+publisher:"Texas A&M University" +contributor:("Batteas, James D")

Texas A&M University

1. He, Xingliang. Synthesis, Characterization, Properties, and Tribological Performance of 2D Nanomaterials.

Degree: PhD, Mechanical Engineering, 2014, Texas A&M University

URL: http://hdl.handle.net/1969.1/152777

► Demand in wear and friction reduction drives continuous development of new lubricant additives for energy saving in wide engineering applications. In the present research, a… (more)

Subjects/Keywords: Lubricant additives; 2D nanomaterials; friction reduction; viscosity modification

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APA (6^th Edition):

He, X. (2014). Synthesis, Characterization, Properties, and Tribological Performance of 2D Nanomaterials. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/152777

Chicago Manual of Style (16^th Edition):

He, Xingliang. “Synthesis, Characterization, Properties, and Tribological Performance of 2D Nanomaterials.” 2014. Doctoral Dissertation, Texas A&M University. Accessed March 04, 2021. http://hdl.handle.net/1969.1/152777.

MLA Handbook (7^th Edition):

He, Xingliang. “Synthesis, Characterization, Properties, and Tribological Performance of 2D Nanomaterials.” 2014. Web. 04 Mar 2021.

Vancouver:

He X. Synthesis, Characterization, Properties, and Tribological Performance of 2D Nanomaterials. [Internet] [Doctoral dissertation]. Texas A&M University; 2014. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/1969.1/152777.

Council of Science Editors:

He X. Synthesis, Characterization, Properties, and Tribological Performance of 2D Nanomaterials. [Doctoral Dissertation]. Texas A&M University; 2014. Available from: http://hdl.handle.net/1969.1/152777

Texas A&M University

2. Werke, Carrie Beth. Chemical and Physical Modification of Graphitic Materials by Oxidative Processes and Solvent Intercalation.

Degree: MS, Chemistry, 2014, Texas A&M University

URL: http://hdl.handle.net/1969.1/153850

► Graphene and graphite are materials of high interest for many applications. In order to increase the possible uses of these materials, more must be understood… (more)

▼ Graphene and graphite are materials of high interest for many applications. In order to increase the possible uses of these materials, more must be understood about how their properties can be modified. One way to modify graphitic properties is by chemical functionalization, such as oxidation. This work looks at two different oxidation techniques for graphite; UV/O3 exposure and biased AFM lithography for broad and local oxidation, respectively. For the supported graphitic samples including graphene, it is important to understand how sample preparation can lead to contamination in addition to investigating how to chemically and physically manipulate the graphitic properties. Three different mechanical exfoliation sample preparations were used to create samples, and each method was investigated with biased lithography. UV/O3 exposure is able to form graphite oxide with only the exposed area undergoing oxidation. It was found that the length of exposure time could be linearly correlated to the amount of defects as determined by Raman spectroscopy. Biased AFM lithography of graphite was also able to oxidize graphite, in a localized pattern instead of entire exposed area. By controlling the lithography conditions, the extent of oxidation in an area could be manipulated. Supported graphitic materials were created via Scotch tape, thermal release tape and water soluble tape. Each tape had unique sample preparation conditions, and each of the three samples yielded single to multilayer graphene surfaces which then underwent biased lithography. Biased lithography on each of these created surfaces demonstrated the impact that sample preparation had on device creation as the samples had unique responses based on which method was used. Scotch tape samples saw growths stemming from the graphitic areas that underwent the biased lithography, thermal release tape samples formed wrinkles in the graphitic region while donuts, on the edges, and the water soluble tape showed oxidation of the graphitic region as well as the formation of bubbles. These bubbles are believed to be due to the solvent intercalation which was able to undergo electrolysis, a novel method for graphitic bubble formation. Advisors/Committee Members: Batteas, James D (advisor), Russell, David H (committee member), Liang, Hong (committee member).

Subjects/Keywords: Graphitic Oxidation; Biased AFM Lithography; Graphitic Bubbles

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APA (6^th Edition):

Werke, C. B. (2014). Chemical and Physical Modification of Graphitic Materials by Oxidative Processes and Solvent Intercalation. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/153850

Chicago Manual of Style (16^th Edition):

Werke, Carrie Beth. “Chemical and Physical Modification of Graphitic Materials by Oxidative Processes and Solvent Intercalation.” 2014. Masters Thesis, Texas A&M University. Accessed March 04, 2021. http://hdl.handle.net/1969.1/153850.

MLA Handbook (7^th Edition):

Werke, Carrie Beth. “Chemical and Physical Modification of Graphitic Materials by Oxidative Processes and Solvent Intercalation.” 2014. Web. 04 Mar 2021.

Vancouver:

Werke CB. Chemical and Physical Modification of Graphitic Materials by Oxidative Processes and Solvent Intercalation. [Internet] [Masters thesis]. Texas A&M University; 2014. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/1969.1/153850.

Council of Science Editors:

Werke CB. Chemical and Physical Modification of Graphitic Materials by Oxidative Processes and Solvent Intercalation. [Masters Thesis]. Texas A&M University; 2014. Available from: http://hdl.handle.net/1969.1/153850

Texas A&M University

3. Park, Kang Han. Investigation of Surfactant, Salt, and Rock Interactions for Performance Improvements of Completion Fluids in the Unconventional Liquids-Rich Reservoir of West Texas.

Degree: MS, Petroleum Engineering, 2018, Texas A&M University

URL: http://hdl.handle.net/1969.1/173500

► Due to their ultra-low permeability and extremely heterogeneous formations, unconventional liquids-rich reservoirs (ULR) need a support of an effective hydraulic fracturing for economic and commercial… (more)

▼ Due to their ultra-low permeability and extremely heterogeneous formations, unconventional liquids-rich reservoirs (ULR) need a support of an effective hydraulic fracturing for economic and commercial oil production. In recent years, the addition of surfactants to the fracturing fluids has been proven to be one of the effective improved oil recovery (IOR) methods in ULR. Meanwhile, rising hydraulic fracturing activities has ignited industrial and environmental concerns for increasing water demand and large volumes of high salinity flowback and produced water. This investigation studies the potential of surfactant and salt mixed aqueous phase solutions for performance improvement of completion fluids, and their interactions with different rock types. This study also provides guidance for the most favorable salt concentration for surfactant-added completion fluids which can potentially lead to economic and environmental benefits. This study focuses on an ULR in West Texas. Five surfactants were selected and mixed at a constant concentration with brines. Brines with nine salinity variations were tested to accurately represent the fluids used or produced in the field, and to determine the most favorable salinity level. All fluids were tested with two different rock types, quartz rich and carbonate rich. Zeta potential, interfacial tension, and contact angle experiments were performed to measure the stability of the liquid film of rock particles, to analyze the impact of surfactant and salt on reducing interfacial tension, and to identify the initial wettability and wettability alteration ability of each fluid, respectively. Then, spontaneous imbibition with timely computer tomography (CT) scans were conducted to visually observe the imbibition performance of completion fluids and to validate correlations between oil recovery and other experimented parameters. Overall, the magnitude of zeta potential, and interfacial tension reduced strongly with increasing salinity, regardless of the presence of surfactant. Also, surfactants mixed with lower salinity brines showed the most effective wettability alteration, and the highest oil recovery factor compared to no or high salinity brines. Similar behaviors and results occurred for all aqueous phase solutions and in both rock types. Among all, wettability of the rock surface was determined to be the most influential factor for oil recovery. Advisors/Committee Members: Schechter, David S (advisor), Zhu, Ding (committee member), Batteas, James D (committee member).

Subjects/Keywords: unconventional; oil; petroleum; surfactant; salinity; rock; surface; wettability; interfacial tension; wettability alteration

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APA (6^th Edition):

Park, K. H. (2018). Investigation of Surfactant, Salt, and Rock Interactions for Performance Improvements of Completion Fluids in the Unconventional Liquids-Rich Reservoir of West Texas. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/173500

Chicago Manual of Style (16^th Edition):

Park, Kang Han. “Investigation of Surfactant, Salt, and Rock Interactions for Performance Improvements of Completion Fluids in the Unconventional Liquids-Rich Reservoir of West Texas.” 2018. Masters Thesis, Texas A&M University. Accessed March 04, 2021. http://hdl.handle.net/1969.1/173500.

MLA Handbook (7^th Edition):

Park, Kang Han. “Investigation of Surfactant, Salt, and Rock Interactions for Performance Improvements of Completion Fluids in the Unconventional Liquids-Rich Reservoir of West Texas.” 2018. Web. 04 Mar 2021.

Vancouver:

Park KH. Investigation of Surfactant, Salt, and Rock Interactions for Performance Improvements of Completion Fluids in the Unconventional Liquids-Rich Reservoir of West Texas. [Internet] [Masters thesis]. Texas A&M University; 2018. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/1969.1/173500.

Council of Science Editors:

Park KH. Investigation of Surfactant, Salt, and Rock Interactions for Performance Improvements of Completion Fluids in the Unconventional Liquids-Rich Reservoir of West Texas. [Masters Thesis]. Texas A&M University; 2018. Available from: http://hdl.handle.net/1969.1/173500

Texas A&M University

4. Minaeian, Mahsa. Scaled-up Purification of Poly(acrylic acid)-Block-Polystyrene Nanoparticles Using Tangential Flow Filtration: A Feasibility Study.

Degree: MS, Chemistry, 2019, Texas A&M University

URL: http://hdl.handle.net/1969.1/188776

► Use of polymeric nanoparticles has gained significant interest in recent years for a wide spectrum of applications such as drug delivery, cell imaging, environmental remediation,… (more)

▼ Use of polymeric nanoparticles has gained significant interest in recent years for a wide spectrum of applications such as drug delivery, cell imaging, environmental remediation, and, electronics. However, many of these nanoparticles have been mainly synthesized at the laboratory scale. Large scale synthesis of these nanoparticles in a cost-effective and reliable fashion could significantly expand their industrial use. In many cases, self-assembly of block polymers into different morphologies involves a transition from a solvated polymer in an organic solvent to a fully aqueous system. Here, the feasibility of using tangential flow filtration (TFF) to scale-up the solution-state transition was studied. A custom-designed and chemically resistant experimental TFF system was built. Nine TFF experiments were performed to study the effects of change of transmembrane pressure, nanoparticles concentration, and hydrophobic/hydrophilic block ratio on solvent removal and nanoparticle size evolution during the diafiltration process. In addition, three batch dialysis experiments were performed to understand the possible extent of scale-up using the proposed system. The designed experimental setup had considerable chemical resistance to many solvents and could be used to conduct small-molecule removal, scaleup, and concentration processes on a wide range of polymers. Feasibility of use of TFF for purification of amphiphilic polymeric nanoparticles with core-shell morphology was demonstrated. Solvent exchange using TFF was considerably faster compared to the traditional batch dialysis system. In TFF experiments, the organic solvent concentration reached the minimum level after 1 hour of in-flow filtration, while it took around 6 hours to reach similar levels of solvent exchange in the batch setting. In addition to an order of magnitude higher processing volumes of TFF compared to dialysis, further scale-up of the TFF process is easily achievable with increasing the membrane area. As expected, higher transmembrane pressure resulted in faster organic solvent removal. The initial nanoparticles concentration had a significant effect on the diameter of the formed structures during the TFF purification, which affected the required purification time. A high ratio of hydrophobic to hydrophilic blocks in a block copolymer increases the chance of precipitation of nanoparticle during TFF, which might terminate the process. Advisors/Committee Members: Wooley, Karen L. (advisor), Batteas, James D. (committee member), Lutkenhaus, Jodie L. (committee member).

Subjects/Keywords: scale-up; tangential flow filtration; polymeric nanoparticles purification; feasibility study

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APA (6^th Edition):

Minaeian, M. (2019). Scaled-up Purification of Poly(acrylic acid)-Block-Polystyrene Nanoparticles Using Tangential Flow Filtration: A Feasibility Study. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/188776

Chicago Manual of Style (16^th Edition):

Minaeian, Mahsa. “Scaled-up Purification of Poly(acrylic acid)-Block-Polystyrene Nanoparticles Using Tangential Flow Filtration: A Feasibility Study.” 2019. Masters Thesis, Texas A&M University. Accessed March 04, 2021. http://hdl.handle.net/1969.1/188776.

MLA Handbook (7^th Edition):

Minaeian, Mahsa. “Scaled-up Purification of Poly(acrylic acid)-Block-Polystyrene Nanoparticles Using Tangential Flow Filtration: A Feasibility Study.” 2019. Web. 04 Mar 2021.

Vancouver:

Minaeian M. Scaled-up Purification of Poly(acrylic acid)-Block-Polystyrene Nanoparticles Using Tangential Flow Filtration: A Feasibility Study. [Internet] [Masters thesis]. Texas A&M University; 2019. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/1969.1/188776.

Council of Science Editors:

Minaeian M. Scaled-up Purification of Poly(acrylic acid)-Block-Polystyrene Nanoparticles Using Tangential Flow Filtration: A Feasibility Study. [Masters Thesis]. Texas A&M University; 2019. Available from: http://hdl.handle.net/1969.1/188776

Texas A&M University

5. Javier, Alnald Caintic. Integrating Experiment and Theory in Electrochemical Surface Science: Studies on the Molecular Adsorption on Noble-Metal Electrode Surfaces by Density Functional Theory, Electron Spectroscopy, and Electrochemistry.

Degree: PhD, Chemistry, 2013, Texas A&M University

URL: http://hdl.handle.net/1969.1/151363

► Computational techniques based on density functional theory (DFT) and experimental methods based on electrochemistry (EC), electrochemical scanning tunneling microscopy (EC-STM), and high-resolution electron energy loss… (more)

▼ Computational techniques based on density functional theory (DFT) and experimental methods based on electrochemistry (EC), electrochemical scanning tunneling microscopy (EC-STM), and high-resolution electron energy loss spectroscopy (HREELS) were employed to study the adsorption of (i) sulfuric acid on Pd(111), (ii) benzene on Pd(111), (iii) hydroquinone/benzoquinone on Pd(111), (iv) hydroquinone sulfonate/benzoquinone sulfonate on Pd(111), (v) 2,3-dimethylhydroquinone/2,3-dimethylbenzoquinone on Pd(111) and polycrystalline Pd, (vi) hydrogen on 1-6 monolayers (ML) of Pd deposited on a Pt(111) substrate, and (vii) a thiolated iron hydrogenase model complex on polycrystalline Au. In situ EC-STM and DFT investigations of sulfuric acid on a Pd(111) surface indicated that two layers of water molecules and hydronium ions are assembled, non-co-planar with one another, between the rows of surface-coordinated sulfate anions; the layer that is slightly elevated is composed of hydronium counter cations. The STM images of benzene chemisorbed on a Pd(111) electrode surface were simulated and the results suggested that, when the potential of the Pd electrode is held at 0.3 V, benzene is chemisorbed on a 3-fold site; while at 0.55 V, the molecule is adsorbed on a position between a 3-fold and a 2-fold site. Computational and experimental results implied that at low concentrations, hydroquinone sulfonate undergoes oxidative chemisorption forming benzoquinone sulfonate (BQS) on the Pd(111) surface, BQS adopts a flat orientation in which the quinone ring is centered over a 2-fold site, and the C–H and C–S bonds are no longer co-planar with the quinone ring and are slightly tilted, directed away from the surface. At very dilute concentrations, when hydroquinone (H_(2)Q) undergoes oxidative chemisorption producing benzoquinone oriented flat, albeit with a slight tilt, on the Pd(111) surface, the flat-adsorbed quinone ring is centered on a bridge site where the C_(2) axis is rotated 30degree from the [110] direction of the metal substrate, the p-oxygen atoms are located above two-fold sites, and the ring is slightly puckered with the C–H bonds tilted away from the surface at approximately 20degree. When 2,3-dimethylH_(2)Q is chemisorbed on the Pd surface, at low concentrations, 2,3-dimethylH_(2)Q is oxidatively chemisorbed producing 2,3-dimethyl-1,4-benzoquinone oriented flat on the surface, the flat-adsorbed rings are centered above 2-fold sites wherein the C=O bonds are pointing 30degree from the [110] direction of the substrate, the para-oxygen atoms are located above bridge sites, the peripheral bonds are tilted away from the surface at ca. 20degree, and at higher concentrations, oxidative chemisorption occurs through activation of the ring’s C–H bonds yielding edge-oriented 2,3-dimethylH_(2)Q. Electrochemistry and DFT results also implied that at 1-2 ML of Pd on Pt(111), hydrogen is only adsorbed on a hollow site while at 3 ML of Pd or more, atomic hydrogen may be chemisorbed on the 3-fold site or absorbed in the… Advisors/Committee Members: Soriaga, Manuel P (advisor), Balbuena, Perla B (advisor), Batteas, James D (committee member), Capareda, Sergio (committee member), Vigh, Gyula (committee member).

Subjects/Keywords: Electrochemical surface science; Adsorption; Surfaces; Density Functional Theory; Electron Spectroscopy; Electrochemistry

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APA (6^th Edition):

Javier, A. C. (2013). Integrating Experiment and Theory in Electrochemical Surface Science: Studies on the Molecular Adsorption on Noble-Metal Electrode Surfaces by Density Functional Theory, Electron Spectroscopy, and Electrochemistry. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/151363

Chicago Manual of Style (16^th Edition):

Javier, Alnald Caintic. “Integrating Experiment and Theory in Electrochemical Surface Science: Studies on the Molecular Adsorption on Noble-Metal Electrode Surfaces by Density Functional Theory, Electron Spectroscopy, and Electrochemistry.” 2013. Doctoral Dissertation, Texas A&M University. Accessed March 04, 2021. http://hdl.handle.net/1969.1/151363.

MLA Handbook (7^th Edition):

Javier, Alnald Caintic. “Integrating Experiment and Theory in Electrochemical Surface Science: Studies on the Molecular Adsorption on Noble-Metal Electrode Surfaces by Density Functional Theory, Electron Spectroscopy, and Electrochemistry.” 2013. Web. 04 Mar 2021.

Vancouver:

Javier AC. Integrating Experiment and Theory in Electrochemical Surface Science: Studies on the Molecular Adsorption on Noble-Metal Electrode Surfaces by Density Functional Theory, Electron Spectroscopy, and Electrochemistry. [Internet] [Doctoral dissertation]. Texas A&M University; 2013. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/1969.1/151363.

Council of Science Editors:

Javier AC. Integrating Experiment and Theory in Electrochemical Surface Science: Studies on the Molecular Adsorption on Noble-Metal Electrode Surfaces by Density Functional Theory, Electron Spectroscopy, and Electrochemistry. [Doctoral Dissertation]. Texas A&M University; 2013. Available from: http://hdl.handle.net/1969.1/151363

Texas A&M University

6. Pawlicki, Alison Andrea. Charge Transport and Directed Assembly of Nano-confined Porphyrin Molecules on Surfaces: Towards Molecular and Organic Electronics.

Degree: PhD, Materials Science and Engineering, 2016, Texas A&M University

URL: http://hdl.handle.net/1969.1/158965

► Presently, the aim of molecular/organic electronics is to incorporate organic materials into conventional silicon-based devices and complimentary metal-oxide semiconductor (CMOS) technology to expand the functionality… (more)

▼ Presently, the aim of molecular/organic electronics is to incorporate organic materials into conventional silicon-based devices and complimentary metal-oxide semiconductor (CMOS) technology to expand the functionality of electronic devices, exploit bottom-up fabrication techniques, and to achieve nanoscopic dimensions. However, the success of molecular/organic electronics depends upon tailoring the function of devices by intentionally modifying the properties of the molecular components starting at the single molecule level and continuing to fabricate meaningful molecular structures. Here, porphyrins were used as a platform to study the structure/electronic property relationship because they are candidates for molecule-containing devices and have vast chemical tunability. The structure of these porphyrins consists of a macrocycle attached to an alkanethiol tether that bonds to Au surfaces and were assembled within a dodecanethiol (C12) self-assembled monolayer (SAM). The physical morphology of the mixed SAM was examined and manipulated by Atomic Force Microscopy (AFM). The molecular-level morphology and the electronic properties were examined by Scanning Tunneling Microscopy (STM). The porphyrin chemical structure was systematically perturbed and allowed to randomly self-assemble within a C12 SAM. Contrary to original expectations of molecular/organic electronics, chemical structure perturbations did not lead to variations in the electronic properties for single porphyrin molecules with consistent indications of tunneling dominated by the alkanethiol tether. To recover the ability to tune the electronic properties, assemblies large enough to stabilize charge were formed with indications of Coulomb Blockade. However, increasing variations in the relative conductance were observed for increasing assembly size. To interrogate this, the electronic properties were examined as a function of assembly duration and a stark difference in the current-voltage (I-V) characteristics attributed to subtle changes in nearest neighbor interactions. To utilize the electronic properties of porphyrins found here in a pre-defined manner, a facile two-step method was developed to direct porphyrin assembly. First, the surface tether, pentanedithiol (C5DT), was controllably attached to the Au(111) surface in pre-defined geometries. Second, porphyrins were selectively attached to the C5DT by “click” chemistry. Employing this method, porphyrins built-up into a pi-stacked hierarchy on the C5DT domains and displayed the desired I-V characteristics. Advisors/Committee Members: Batteas, James D (advisor), Seminario, Jorge M (committee member), Vaddiraju, Sreeram (committee member), Lucchese, Robert R (committee member).

Subjects/Keywords: organic electronics; molecular electronics; surface science; nanotechnology; charge transport; scanning tunneling microscopy; atomic force microscopy; porphyrin; self-assembly; directed assembly; self assembled monolayer; nanografting; scanning tunneling spectroscopy; current-voltage; tunneling; charge hopping; tunneling decay constant; tunneling efficiency; alkanethiol

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APA (6^th Edition):

Pawlicki, A. A. (2016). Charge Transport and Directed Assembly of Nano-confined Porphyrin Molecules on Surfaces: Towards Molecular and Organic Electronics. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/158965

Chicago Manual of Style (16^th Edition):

Pawlicki, Alison Andrea. “Charge Transport and Directed Assembly of Nano-confined Porphyrin Molecules on Surfaces: Towards Molecular and Organic Electronics.” 2016. Doctoral Dissertation, Texas A&M University. Accessed March 04, 2021. http://hdl.handle.net/1969.1/158965.

MLA Handbook (7^th Edition):

Pawlicki, Alison Andrea. “Charge Transport and Directed Assembly of Nano-confined Porphyrin Molecules on Surfaces: Towards Molecular and Organic Electronics.” 2016. Web. 04 Mar 2021.

Vancouver:

Pawlicki AA. Charge Transport and Directed Assembly of Nano-confined Porphyrin Molecules on Surfaces: Towards Molecular and Organic Electronics. [Internet] [Doctoral dissertation]. Texas A&M University; 2016. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/1969.1/158965.

Council of Science Editors:

Pawlicki AA. Charge Transport and Directed Assembly of Nano-confined Porphyrin Molecules on Surfaces: Towards Molecular and Organic Electronics. [Doctoral Dissertation]. Texas A&M University; 2016. Available from: http://hdl.handle.net/1969.1/158965

Texas A&M University

7. Zigmond, Jennifer Summerhill. Development and Testing of Intricate, Amphiphilic Crosslinked Hyperbranched Fluoropolymers with Integrated Liquid Crystalline Properties as Anti-Icing Coatings in Aerospace and Defense Applications.

Degree: PhD, Chemistry, 2016, Texas A&M University

URL: http://hdl.handle.net/1969.1/158935

► Atmospheric icing, the process by which supercooled water droplets freeze upon contact with a surface, has proven to be devasting when not controlled or prevented.… (more)

▼ Atmospheric icing, the process by which supercooled water droplets freeze upon contact with a surface, has proven to be devasting when not controlled or prevented. Currently, the solution for addressing this problem is the use of deicing fluids, which are toxic and inefficient, leading to the development of intrinsically anti-icing materials to focus on prevention rather than response after manifestation. Amphiphilic polymer coatings have been of particular interest as they are capable of presenting complex nano- and microscopic heterogeneities for inhibition of ice formation, which is not a typical approach toward anti-icing technologies. We have previously synthesized crosslinked networks comprised of hyperbranched fluoropolymers (HBFP) and poly(ethylene glycol) (PEG), which demonstrated superb anti-biofouling capabilities credited to their amphiphilic morphology, nanoscopic surface topography and dynamic surface reorganization. Through the tuning of the amphiphilicity and thermo-responsive molecular ordering of this crosslinked hyperbranched network, we expand the application of these materials by exploiting their characteristics for development of robust, dynamic, anti-icing coatings for aerospace applications. An array of films was synthesized by varying the PEG crosslinker to study the effect of hydrophilic:hydrophobic component ratios on the thermal, mechanical and surface properties. Differential scanning calorimetry (DSC) data show significant reductions in the water melting transition temperatures (-5 ⁰C and -27 ⁰C for free and bound water, respectively). The novel application of this system displays the expansion and diversity of a well-established coating that demonstrates unique water confinement and sequestration behaviors with the ability to reorganize at the surface. Due to its great potential as an anti-icing coating, additional investigations and chemical manipulation of the binary system led to the integration of a thermally-dynamic molecule, a liquid crystalline (LC) moiety. A library of LC systems was developed in order to probe the effects that size, mesophase and topology would have on the water depression efficiency of these materials. An LC monomer was incorporated into the polymer during polymerization in order to enhance the dynamic reorganization of the system during changes in temperature and wetting. The results suggest that the unique LC-HBFP system is a viable option as a dynamic coating for extreme environments. Advisors/Committee Members: Wooley, Karen L (advisor), Batteas, James D (committee member), Wheeler, Steven E (committee member), Liang, Hong (committee member).

Subjects/Keywords: anti-icing; amphiphilic; liquid crystalline; dynamic; coatings

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APA (6^th Edition):

Zigmond, J. S. (2016). Development and Testing of Intricate, Amphiphilic Crosslinked Hyperbranched Fluoropolymers with Integrated Liquid Crystalline Properties as Anti-Icing Coatings in Aerospace and Defense Applications. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/158935

Chicago Manual of Style (16^th Edition):

Zigmond, Jennifer Summerhill. “Development and Testing of Intricate, Amphiphilic Crosslinked Hyperbranched Fluoropolymers with Integrated Liquid Crystalline Properties as Anti-Icing Coatings in Aerospace and Defense Applications.” 2016. Doctoral Dissertation, Texas A&M University. Accessed March 04, 2021. http://hdl.handle.net/1969.1/158935.

MLA Handbook (7^th Edition):

Zigmond, Jennifer Summerhill. “Development and Testing of Intricate, Amphiphilic Crosslinked Hyperbranched Fluoropolymers with Integrated Liquid Crystalline Properties as Anti-Icing Coatings in Aerospace and Defense Applications.” 2016. Web. 04 Mar 2021.

Vancouver:

Zigmond JS. Development and Testing of Intricate, Amphiphilic Crosslinked Hyperbranched Fluoropolymers with Integrated Liquid Crystalline Properties as Anti-Icing Coatings in Aerospace and Defense Applications. [Internet] [Doctoral dissertation]. Texas A&M University; 2016. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/1969.1/158935.

Council of Science Editors:

Zigmond JS. Development and Testing of Intricate, Amphiphilic Crosslinked Hyperbranched Fluoropolymers with Integrated Liquid Crystalline Properties as Anti-Icing Coatings in Aerospace and Defense Applications. [Doctoral Dissertation]. Texas A&M University; 2016. Available from: http://hdl.handle.net/1969.1/158935

Texas A&M University

8. Yao, Haiqing. Surface Functionalization of 1-D and 2-D Carbon-Based Nanomaterials and Their Applications.

Degree: PhD, Materials Science and Engineering, 2015, Texas A&M University

URL: http://hdl.handle.net/1969.1/186996

► Carbon nanotubes (CNTs) and graphene are dominant and emerging carbon-based materials that have attracted extensive attention for potential applications in advanced nanotechnology. The attractiveness of… (more)

▼ Carbon nanotubes (CNTs) and graphene are dominant and emerging carbon-based materials that have attracted extensive attention for potential applications in advanced nanotechnology. The attractiveness of these materials originates from their excellent mechanical, thermal, and electrical properties. However, their insolubility and difficult processability in solvents have significantly limited their use. To solve these problems, surface functionalization is used to increase their solubility, enhance their processability in solvents, and integrate these materials into nanodevices. Conventional methods are being challenged due to their ineffective and insufficient control of the functionalization of CNTs or graphene, which is critical to realize tailored structures with unprecedented optical, electrical and catalytic properties. Further development in this field requires a fundamental understanding of the steps involved in surface functionalization, namely the reaction mechanism(s) and controlled kinetics, to yield tailored structures. The overall objective of my dissertation is to develop new approaches to functionalizing CNTs and graphene, study the functionalization mechanism and kinetics, and fabricate tailored structures with unprecedented properties. The study begins with developing new covalent functionalization methods for CNTs and graphene based on the defect chemistry method. This method is less destructive and more reactive compared to the conjugate structure method. Amination of MWCNTs with octadecylamine on the mutual position of pyracyclene units in the closed caps and pentagons on the MWCNT sidewalls is developed. The functionalized MWCNTs possess controllable surface wettability. For covalent functionalization of GO, dual-function silane agents were reacted with GO through oxygen containing groups. The exposed amine groups of the functionalized GO could effectively template the assembly of Au nanoparticles on the graphene surface with high density and good dispersity. The GO-Au composites exhibit improved surface-enhanced Raman scattering and enhanced efficiency in catalytic applications. For the noncovalent method, ZnO-CNT and ZnO-GO composites were prepared. Due to the electronegative nature of CNTs and GO, ZnO nanoparticles with positive charges can anchor on their surfaces through electrostatic attraction. The creative combination of CNTs or graphene and ZnO leads to higher efficiency and stability for photocatalytic applications than the corresponding components, which makes them a new class of functional materials to advance nanotechnology. Advisors/Committee Members: Su, Hung-Jue (advisor), Bluemel, Janet (committee member), Batteas, James D (committee member), Creasy, Terry (committee member).

Subjects/Keywords: Carbon nanotube; graphene; surface functionalization

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APA (6^th Edition):

Yao, H. (2015). Surface Functionalization of 1-D and 2-D Carbon-Based Nanomaterials and Their Applications. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/186996

Chicago Manual of Style (16^th Edition):

Yao, Haiqing. “Surface Functionalization of 1-D and 2-D Carbon-Based Nanomaterials and Their Applications.” 2015. Doctoral Dissertation, Texas A&M University. Accessed March 04, 2021. http://hdl.handle.net/1969.1/186996.

MLA Handbook (7^th Edition):

Yao, Haiqing. “Surface Functionalization of 1-D and 2-D Carbon-Based Nanomaterials and Their Applications.” 2015. Web. 04 Mar 2021.

Vancouver:

Yao H. Surface Functionalization of 1-D and 2-D Carbon-Based Nanomaterials and Their Applications. [Internet] [Doctoral dissertation]. Texas A&M University; 2015. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/1969.1/186996.

Council of Science Editors:

Yao H. Surface Functionalization of 1-D and 2-D Carbon-Based Nanomaterials and Their Applications. [Doctoral Dissertation]. Texas A&M University; 2015. Available from: http://hdl.handle.net/1969.1/186996

Texas A&M University

9. Lundwall, Matthew James. Characterization and Reaction Studies of Silica Supported Platinum and Rhodium Model Catalysts.

Degree: PhD, Chemistry, 2012, Texas A&M University

URL: http://hdl.handle.net/1969.1/ETD-TAMU-2010-12-8839

► The physical and catalytic properties of silica supported platinum or rhodium model catalysts are studied under both ultra high vacuum (UHV) and elevated pressure reaction… (more)

▼ The physical and catalytic properties of silica supported platinum or rhodium model catalysts are studied under both ultra high vacuum (UHV) and elevated pressure reaction conditions (>1torr). Platinum or rhodium nanoparticles are vapor deposited onto a SiO2/Mo(112) surface and characterized using various surface analytical methods. CO chemisorption is utilized as a surface probe to estimate the concentration of various sites on the nanoparticles through thermal desorption spectroscopy (TDS) and infrared reflection absorption spectroscopy (IRAS) along with microscopy techniques to estimate particle size. The results are compared with hard sphere models of face centered cubic metals described as truncated cubo-octahedron. Results demonstrate the excellent agreement between chemisorption and hard sphere models in estimating the concentration of undercoordinated atoms on the nanoparticle surface. Surfaces are then subjected to high pressure reaction conditions to test the efficacy of utilizing the rate of a chemical reaction to obtain structural information about the surface. The surfaces are translated in-situ to a high pressure reaction cell where both structure insensitive and sensitive reactions are performed. Structure insensitive reactions (e.g. CO oxidation) allow a method to calculate the total active area on a per atom basis for silica supported platinum and rhodium model catalysts under reaction conditions. While structure sensitive reactions allow an estimate of the types of reaction sites, such as step sites (≤C7) under reaction conditions (e.g. n-heptane dehydrocyclization). High pressure structure sensitive reactions (e.g. ethylene hydroformylation) are also shown to drastically alter the morphology of the surface by dispersing nanoparticles leading to inhibition of catalytic pathways. Moreover, the relationships between high index single crystals, oxide supported nanoparticles, and high surface area technical catalysts are established. Overall, the results demonstrate the utility of model catalysts in understanding the structure-activity relationships in heterogeneous catalytic reactions and the usefulness of high pressure reactions as an analytical probe of surface morphology. Advisors/Committee Members: Goodman, D. Wayne (advisor), Batteas, James D. (committee member), Soriaga, Manuel P. (committee member), Shantz, Daniel F. (committee member).

Subjects/Keywords: Platinum; Rhodium; Model Catalysts; nanoparticles; ethylene; carbon monoxide; CO oxidation; hydroformylation; dehydrocyclization

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APA (6^th Edition):

Lundwall, M. J. (2012). Characterization and Reaction Studies of Silica Supported Platinum and Rhodium Model Catalysts. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2010-12-8839

Chicago Manual of Style (16^th Edition):

Lundwall, Matthew James. “Characterization and Reaction Studies of Silica Supported Platinum and Rhodium Model Catalysts.” 2012. Doctoral Dissertation, Texas A&M University. Accessed March 04, 2021. http://hdl.handle.net/1969.1/ETD-TAMU-2010-12-8839.

MLA Handbook (7^th Edition):

Lundwall, Matthew James. “Characterization and Reaction Studies of Silica Supported Platinum and Rhodium Model Catalysts.” 2012. Web. 04 Mar 2021.

Vancouver:

Lundwall MJ. Characterization and Reaction Studies of Silica Supported Platinum and Rhodium Model Catalysts. [Internet] [Doctoral dissertation]. Texas A&M University; 2012. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2010-12-8839.

Council of Science Editors:

Lundwall MJ. Characterization and Reaction Studies of Silica Supported Platinum and Rhodium Model Catalysts. [Doctoral Dissertation]. Texas A&M University; 2012. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2010-12-8839

Texas A&M University

10. Link, Lauren A. Degradable Polycarbonate Networks Derived from Quinic Acid and Designed for Biomedical Applications.

Degree: PhD, Materials Science and Engineering, 2015, Texas A&M University

URL: http://hdl.handle.net/1969.1/156419

► The pursuit of polymers with natural and renewable precursors is driven by two specific aims: (i) to develop sustainable and biodegradable plastics which decrease dependence… (more)

▼ The pursuit of polymers with natural and renewable precursors is driven by two specific aims: (i) to develop sustainable and biodegradable plastics which decrease dependence on petroleum feedstocks and address problems associated with plastic waste and pollution, and (ii) to design novel biomaterials with built-in biocompatibility and the ability to degrade under physiological conditions to produce resorbable natural byproducts. Herein, a new family of nontoxic bio-based polycarbonate networks that exhibit a wide range of achievable thermomechanical properties and have the potential to breakdown hydrolytically into biologically-beneficial and environmentally-benign degradation products is described. The natural product quinic acid, known for its antioxidant and growth-promoting properties, was selected as the monomeric building block, and hydrolytically labile carbonates were selected as the linkages. Solvent-free thiol-ene chemistry was utilized in the copolymerization of tris(alloc) quinic acid and a variety of multifunctional thiol monomers to obtain poly(thioether-co-carbonate) networks. Natural multifunctional thiols derived from lipoic acid, a metabolic antioxidant, were explored to further increase the overall natural content of the material. A wide range of tunable thermomechanical properties including glass transition temperatures from −18 to 65 °C and mechanical characteristics from a rubbery elastomer to a rigid plastic was achieved by careful selection of thiol monomers. Special attention was paid to the characterization of structure-thermomechanical property relationships and how these relationships change under physiological conditions. The short-term mechanical changes triggered by solvent plasticization in a physiologically-relevant environment (PBS, pH 7.4, 37 °C) were observed by submersion dynamic mechanical analysis. The long-term degradation kinetics, including swelling and mass loss, were monitored, and the results showed a range of degradation times from 5 to ~35 weeks based on the crosslink density and hydrophilicity of the polymer network. In vitro cytotoxicity and cell attachment studies were performed, and X-ray imaging contrast properties were observed to investigate the feasibility of the poly(thioether-co-carbonate) networks to serve as platform materials in biomedical applications, specifically as orthopedic implant devices. Overall, by using simple fabrication techniques and reliable chemistry, the poly(thioether-co-carbonate) networks developed in this work represent a versatile and nontoxic family of materials which may be used for to a wide variety of applications. Advisors/Committee Members: Wooley, Karen L (advisor), Grunlan, Melissa A (committee member), Maitland, Duncan J (committee member), Batteas, James D (committee member).

Subjects/Keywords: polycarbonates; thiol-ene; crosslinked networks; degradable; quinic acid

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APA (6^th Edition):

Link, L. A. (2015). Degradable Polycarbonate Networks Derived from Quinic Acid and Designed for Biomedical Applications. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/156419

Chicago Manual of Style (16^th Edition):

Link, Lauren A. “Degradable Polycarbonate Networks Derived from Quinic Acid and Designed for Biomedical Applications.” 2015. Doctoral Dissertation, Texas A&M University. Accessed March 04, 2021. http://hdl.handle.net/1969.1/156419.

MLA Handbook (7^th Edition):

Link, Lauren A. “Degradable Polycarbonate Networks Derived from Quinic Acid and Designed for Biomedical Applications.” 2015. Web. 04 Mar 2021.

Vancouver:

Link LA. Degradable Polycarbonate Networks Derived from Quinic Acid and Designed for Biomedical Applications. [Internet] [Doctoral dissertation]. Texas A&M University; 2015. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/1969.1/156419.

Council of Science Editors:

Link LA. Degradable Polycarbonate Networks Derived from Quinic Acid and Designed for Biomedical Applications. [Doctoral Dissertation]. Texas A&M University; 2015. Available from: http://hdl.handle.net/1969.1/156419

Texas A&M University

11. Nagaraja, Ashvin T. Nanomaterial Modification for Bioconjugation and Enhanced Stability Towards Optical Sensor Development.

Degree: PhD, Biomedical Engineering, 2015, Texas A&M University

URL: http://hdl.handle.net/1969.1/156490

► The evolving field of nanomaterial synthesis needs adaptable techniques for the modification and construction of multifunctional components. In this work, a unique layer-by-layer (LbL) method… (more)

▼ The evolving field of nanomaterial synthesis needs adaptable techniques for the modification and construction of multifunctional components. In this work, a unique layer-by-layer (LbL) method is demonstrated as a generic pathway for nanomaterial stabilization and bioconjugation, facilitating manipulation and handling for new applications. In particular, nanomaterials have unique optical properties that can potentially improve the sensitivity and long-term performance in applications such as optical biosensors, particularly those based on energy transfer. However, the reproducible integration of nanomaterials into stable assays remains a significant challenge. Therefore, the generalized LbL technique was specifically applied towards the fabrication of a novel nanomaterial-enabled optical sensor. The broader implications of this LbL technique on nanoparticles were explored by characterizing the capabilities and performance of multiple nanoscale core materials and prospective polymer coatings. The modified nanomaterials were characterized for their colloidal and optical stability under varying pH, buffer, and ionic strength conditions. A single bilayer coating of weak and weak-strong polymers using the developed procedure was capable of imparting colloidal stability with a minimal hydrodynamic size increase; an essential feature for energy transfer sensors. The application of this LbL coating was demonstrated for the construction of a nanomaterial-enabled energy transfer sensor utilizing concanavalin A (ConA)-coated gold nanorods (energy acceptors) combined with fluorescent gold nanoclusters (NCs) grown within ovalbumin (OVA) (energy donors). The successful construction of the sensor components was verified and the concept demonstrated via reversible quenching in the presence of increasing glucose concentrations. Calcium carbonate was explored as a porous template for the encapsulation of affinity sensing chemistry. The entire process was studied; synthesis of the carbonate template, capsule formation via LbL, and dissolution of carbonate to form a hollow capsule, along with the incorporation of assay components using co-precipitation. The knowledge gained provides fundamental insight for improving the function of sensor schemes utilizing carbonate and to guide future considerations for encapsulation. These results demonstrate significant advances for the reliable fabrication of nanomaterial-enabled optical sensors. The fundamental knowledge and experimental expertise developed shall guide the rational design of future sensor iterations for improved performance. Advisors/Committee Members: McShane, Michael J (advisor), Meissner, Kenith E (committee member), Batteas, James D (committee member), Applegate, Brian E (committee member).

Subjects/Keywords: nanomaterial; sensor; polymer; polyelectrolyte; colloid; bioconjugation; hydrodynamic size; nanoparticle; quantum dot; gold; energy transfer

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APA (6^th Edition):

Nagaraja, A. T. (2015). Nanomaterial Modification for Bioconjugation and Enhanced Stability Towards Optical Sensor Development. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/156490

Chicago Manual of Style (16^th Edition):

Nagaraja, Ashvin T. “Nanomaterial Modification for Bioconjugation and Enhanced Stability Towards Optical Sensor Development.” 2015. Doctoral Dissertation, Texas A&M University. Accessed March 04, 2021. http://hdl.handle.net/1969.1/156490.

MLA Handbook (7^th Edition):

Nagaraja, Ashvin T. “Nanomaterial Modification for Bioconjugation and Enhanced Stability Towards Optical Sensor Development.” 2015. Web. 04 Mar 2021.

Vancouver:

Nagaraja AT. Nanomaterial Modification for Bioconjugation and Enhanced Stability Towards Optical Sensor Development. [Internet] [Doctoral dissertation]. Texas A&M University; 2015. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/1969.1/156490.

Council of Science Editors:

Nagaraja AT. Nanomaterial Modification for Bioconjugation and Enhanced Stability Towards Optical Sensor Development. [Doctoral Dissertation]. Texas A&M University; 2015. Available from: http://hdl.handle.net/1969.1/156490

Texas A&M University

12. Geng, Sheng. Investigation of Hypervelocity Massive Projectile- Graphene Interaction and Characterization of Individual Free-standing Nanoparticles in the Transmission Direction by Massive Cluster Secondary Ion Mass Spectrometry.

Degree: PhD, Chemistry, 2017, Texas A&M University

URL: http://hdl.handle.net/1969.1/161315

► It has been shown that secondary ion emission from ultra-thin foils is notably enhanced in the transmission direction. This feature should be of interest for… (more)

▼ It has been shown that secondary ion emission from ultra-thin foils is notably enhanced in the transmission direction. This feature should be of interest for examining nano-objects. A pre-requisite is to deposit them on as thin a support as possible. For this study graphene was chosen. Free-standing graphene was bombarded alone and with deposition of dispersed nanoparticles in a setup enabling bombardment at 0⁰ and secondary ion (SI) detection in transmission in-line with the incident projectiles. C¹,2+ 60 and Au⁴⁺ 400 at impact energies of ∼0.4, 0.8 and 1.2 keV/atom respectively were used as primary ions. The experiments were run as a sequence of single projectile impacts with each time separate recording of the SIs identified via ToF-MS. In order to improve the understanding of the graphene as a potential quasi-immaterial substrate for the deposition of sub-monolayer nanoparticles, the 1-layer and 4-layer graphene were impacted by the individual 25 and 50 keV C¹,2+ 60 projectiles and negative SIs and secondary electrons (SEs) were collected in the transmission direction. The yields of C− n (n ≤ 4) are above 10% and decrease exponentially with n. The results are explained with the aid of molecular dynamics (MD) simulation. The ionization probability was estimated by comparing the SI yields of C− n to the yields of C 0 n from MD simulation. The ions come from the thermally excited rim of the impact hole damped by cluster fragmentation and electron detachment. The SE probability distributions are Poisson-like, and on average 3 thermal electrons are emitted per impact. The interaction of a 2D projectile on a 2D target is fundamentally different from that on a 3D material. 1-layer graphene was also impacted by the 440-540 keV Au4+ 400 projectiles in both positive and negative ion modes in the transmission direction. The projectiles penetrated the graphene and the Au± 1−3 fragment ions were observed as well as C± n. During the impact, ∼15% of the initial kinetic energy is lost. The Au projectiles are neutralized when approaching the graphene, and then partially ionized again (positively and negatively) via electron tunneling from the hot rims of the impact hole on graphene. The projectiles obtain an internal energy of ∼500 eV (∼4900 K) after the impact. They undergo a ∼90 step fragmentation with the ejection of Au1 atoms in the experimental time range of ∼0.1 µs. Individual free-standing 5 nm gold nanoparticles coated with dodecanethiol were deposited on graphene film and bombarded with Au⁴⁺ 400 and C¹,2+ 60 . The graphene substrate contributed few SIs beyond m/z 120, facilitating the detection of moieties attached to the nanoparticles. Compared to reflection SIMS, transmission SIMS shows a ∼4 times higher effective yield of molecular ions from the dodecanethiol coating. The SI yields from Au⁴⁺ 400 impact are ∼3 times higher than those from C²⁺ 60 impact. The yield of the dodecanethiol molecular ion is 1.0 × 10^−4 from the Au⁴⁺ 400 bombardment and 3.0 × 10^−5 from the C²⁺ 60 bombardment. In this case,… Advisors/Committee Members: Schweikert, Emile A (advisor), Russell, David H (committee member), Batteas, James D (committee member), Grunlan, Jaime C (committee member).

Subjects/Keywords: Secondary ion mass spectrometry; Gold nanoparticles; graphene; Projectile-2D material interaction

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APA (6^th Edition):

Geng, S. (2017). Investigation of Hypervelocity Massive Projectile- Graphene Interaction and Characterization of Individual Free-standing Nanoparticles in the Transmission Direction by Massive Cluster Secondary Ion Mass Spectrometry. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/161315

Chicago Manual of Style (16^th Edition):

Geng, Sheng. “Investigation of Hypervelocity Massive Projectile- Graphene Interaction and Characterization of Individual Free-standing Nanoparticles in the Transmission Direction by Massive Cluster Secondary Ion Mass Spectrometry.” 2017. Doctoral Dissertation, Texas A&M University. Accessed March 04, 2021. http://hdl.handle.net/1969.1/161315.

MLA Handbook (7^th Edition):

Geng, Sheng. “Investigation of Hypervelocity Massive Projectile- Graphene Interaction and Characterization of Individual Free-standing Nanoparticles in the Transmission Direction by Massive Cluster Secondary Ion Mass Spectrometry.” 2017. Web. 04 Mar 2021.

Vancouver:

Geng S. Investigation of Hypervelocity Massive Projectile- Graphene Interaction and Characterization of Individual Free-standing Nanoparticles in the Transmission Direction by Massive Cluster Secondary Ion Mass Spectrometry. [Internet] [Doctoral dissertation]. Texas A&M University; 2017. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/1969.1/161315.

Council of Science Editors:

Geng S. Investigation of Hypervelocity Massive Projectile- Graphene Interaction and Characterization of Individual Free-standing Nanoparticles in the Transmission Direction by Massive Cluster Secondary Ion Mass Spectrometry. [Doctoral Dissertation]. Texas A&M University; 2017. Available from: http://hdl.handle.net/1969.1/161315

Texas A&M University

13. Seetho, Kellie. Developing New Methodologies for Anti-Fouling Polymeric Network Syntheses, Orthogonal Modifications, and Applications in Marine Environment.

Degree: PhD, Chemistry, 2016, Texas A&M University

URL: http://hdl.handle.net/1969.1/174228

► Biofouling on ship hulls and other surfaces calls for immediate attention as fouling organisms increase both friction and weight of vessels, resulting in wasted fuel… (more)

▼ Biofouling on ship hulls and other surfaces calls for immediate attention as fouling organisms increase both friction and weight of vessels, resulting in wasted fuel consumption, travel time, and cleaning resources. There are currently many efforts to develop polymeric networks as anti-fouling coatings to replace traditional anti-fouling paints, which contain toxic compounds. This dissertation focuses on the development of new methodologies for anti-fouling polymeric network syntheses, orthogonal modifications, characterization and anti-fouling properties for marine anti-fouling applications. A terpolymer network based on hyperbranched fluoropolymers crosslinked with poly(ethylene glycol) and polydimethylsiloxane that displayed improved fouling releasing properties was generated. Methodologies and experiments were designed and performed to investigate the stability and crosslinking efficiency of the network when the crosslinking polymers were increased. The concept of using a three-component system was retained while changing each component. A ternary network of silsesquioxanes, an amphiphilic fluorinated compound and sulfobetaines was generated by thiol-ene click chemistry and to form coatings. The anti-fouling performances of the coatings were then tested against various marine fouling organisms. A facile, two-step modification to generate an amphiphilic zwitterionic copolymer from a commodity copolymer was also explored. A copolymer containing hydrophobic units and reactive units was synthesized and subsequently modified to produce an amphiphilic, zwitterionic polymer. The amphiphilic zwitterionic polymer was covalently attached onto silanized glass with different crosslinking extents to form amphiphilic crosslinked networks. The surface properties of the resultant polymer coating can be easily tuned by varying the extent of cross-linking in the network. Anti-fouling studies of bovine serum albumin and Ulva zoospores suggest that this system displayed potential as an anti-fouling material. Lastly, the thermal and mechanical properties of zwitterionic vs. blended ionic polymers were investigated. Different charged polymers were prepared by functionalizing poly[(allyl glycidyl ether)-b-(ethylene oxide)-b-(allyl glycidyl ether)] (P(AGE-b-EO-b-AGE)) with different charged thiols through highly efficient photoinitiated thiol-ene chemistry. Equimolar amounts of polymers with positive charged side chains and negative charged side chains were then mixed together and compared to polymers with zwitterionic side chains that possess similar charge densities. The bulk polymers were characterized by thermogravimetric analysis, differential scanning calorimetry, and dynamic mechanical thermal analysis to study the effect of the nature of ionic interactions of the charged polymers. Advisors/Committee Members: Wooley, Karen L (advisor), Bergbreiter, David E (committee member), Batteas, James D (committee member), Grunlan, Melissa A (committee member).

Subjects/Keywords: anti-fouling; polymer

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APA (6^th Edition):

Seetho, K. (2016). Developing New Methodologies for Anti-Fouling Polymeric Network Syntheses, Orthogonal Modifications, and Applications in Marine Environment. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/174228

Chicago Manual of Style (16^th Edition):

Seetho, Kellie. “Developing New Methodologies for Anti-Fouling Polymeric Network Syntheses, Orthogonal Modifications, and Applications in Marine Environment.” 2016. Doctoral Dissertation, Texas A&M University. Accessed March 04, 2021. http://hdl.handle.net/1969.1/174228.

MLA Handbook (7^th Edition):

Seetho, Kellie. “Developing New Methodologies for Anti-Fouling Polymeric Network Syntheses, Orthogonal Modifications, and Applications in Marine Environment.” 2016. Web. 04 Mar 2021.

Vancouver:

Seetho K. Developing New Methodologies for Anti-Fouling Polymeric Network Syntheses, Orthogonal Modifications, and Applications in Marine Environment. [Internet] [Doctoral dissertation]. Texas A&M University; 2016. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/1969.1/174228.

Council of Science Editors:

Seetho K. Developing New Methodologies for Anti-Fouling Polymeric Network Syntheses, Orthogonal Modifications, and Applications in Marine Environment. [Doctoral Dissertation]. Texas A&M University; 2016. Available from: http://hdl.handle.net/1969.1/174228

Texas A&M University

14. Hosseinali, Farzad. Surface Attributes and Multiscale Frictional Properties of Cotton (Gossypium Hirsutum L.) Fibers.

Degree: PhD, Biological and Agricultural Engineering, 2018, Texas A&M University

URL: http://hdl.handle.net/1969.1/173290

► Frictional properties of fiber assemblies from different cotton varieties were investigated using a sliding friction tester. Results indicated that frictional characteristics of cotton fibers varied… (more)

▼ Frictional properties of fiber assemblies from different cotton varieties were investigated using a sliding friction tester. Results indicated that frictional characteristics of cotton fibers varied significantly among varieties. A significant, negative correlation between friction coefficient (μ) and fiber yellowness and a strong positive correlation between μ and short-fiber content were observed. Multilinear regression analysis showed that fiber friction is a complex phenomenon that depends on fiber dimensional, mechanical, and surface properties. In addition, a fiber simulation model was developed to explain the partial relationships between the fiber dimensional properties and its frictional characteristics. The model shows that, for assemblies of fibers with the same mass and equal average mean length, the true contact area increases with decreasing fiber maturity and fineness. In the second phase of this research, surface of cotton fibers from two different samples—with statistically distinct macroscale frictional properties—were further characterized at the nanoscale using various atomic force microscope (AFM) operation modes. A cotton fiber surface is naturally coated with a few hundred nanometer-thick layer of lipids, fatty acids, alcohols, and pectins, collectively called the cotton cuticular wax. Surface topography and friction images of the fibers were obtained with conventional contact mode AFM. The nanomechanical property images—such as adhesion and deformation—were obtained in force tapping mode. The results indicate that fibers with higher macroscale friction were also associated with higher nanoscale friction, adhesion, and deformation. The differences in nanoscale friction, adhesion, and deformation signals is attributed to fiber surface hydrophobicity and stiffness, which in turn may depend on the waxy layer thickness, fatty acids hydrocarbon chain length, and film viscosity. Advisors/Committee Members: Thomasson, John A (advisor), Batteas, James D (committee member), Hequet, Eric F (committee member), Fernando, Sandun (committee member).

Subjects/Keywords: Cotton fiber; Friction; Fiber Modeling; Nanofriction

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APA (6^th Edition):

Hosseinali, F. (2018). Surface Attributes and Multiscale Frictional Properties of Cotton (Gossypium Hirsutum L.) Fibers. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/173290

Chicago Manual of Style (16^th Edition):

Hosseinali, Farzad. “Surface Attributes and Multiscale Frictional Properties of Cotton (Gossypium Hirsutum L.) Fibers.” 2018. Doctoral Dissertation, Texas A&M University. Accessed March 04, 2021. http://hdl.handle.net/1969.1/173290.

MLA Handbook (7^th Edition):

Hosseinali, Farzad. “Surface Attributes and Multiscale Frictional Properties of Cotton (Gossypium Hirsutum L.) Fibers.” 2018. Web. 04 Mar 2021.

Vancouver:

Hosseinali F. Surface Attributes and Multiscale Frictional Properties of Cotton (Gossypium Hirsutum L.) Fibers. [Internet] [Doctoral dissertation]. Texas A&M University; 2018. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/1969.1/173290.

Council of Science Editors:

Hosseinali F. Surface Attributes and Multiscale Frictional Properties of Cotton (Gossypium Hirsutum L.) Fibers. [Doctoral Dissertation]. Texas A&M University; 2018. Available from: http://hdl.handle.net/1969.1/173290

Texas A&M University

15. Silveira, Joshua A. Development of Ion Mobility-mass Spectrometry Instrumentation to Probe the Conformations and Capture the Solution to Gas Phase Transition of Electrosprayed Biomolecules.

Degree: PhD, Chemistry, 2013, Texas A&M University

URL: http://hdl.handle.net/1969.1/151729

► Recent progress has been made developing ion mobility-mass spectrometry (IM-MS) instruments for biophysical studies; however, experimental techniques that can probe the structure and/or dynamics of… (more)

▼ Recent progress has been made developing ion mobility-mass spectrometry (IM-MS) instruments for biophysical studies; however, experimental techniques that can probe the structure and/or dynamics of biomolecules at intermediate extents of hydration are limited and little is known about the final stages of desolvation during electrospray ionization (ESI). Here, ion optical devices, analytical methodology, and instrument platforms are developed to study the conformations of structurally labile biomolecules (i.e., peptides and proteins) produced upon ESI and provide new insight into their solution to gas phase evolution. First, fundamental principles of periodic focusing ion mobility spectrometry are comprehensively discussed. Radial ion confinement is attributed to a collisionally dampened effective potential that ultimately results in high ion transmission. Detailed equations of motion are derived that culminate into useful methodology for accurate determination of peptide and protein collision cross section values via inclusion of a mobility dampening coefficient. Second, evaporation of water from extensively hydrated protons and peptides formed by ESI is examined for the first time using a new cryogenic (80 K) IM-MS instrument platform. Key parameters that influence the cluster distributions are critically examined. In agreement with previous studies, the findings indicate that water evaporation is largely dependent upon the particular charge-carrying species within the cluster. IM-MS results for protonated water clusters suggest that the special stability of the well-known H^(+)(H_(2)O)_(n) (n = 21) “magic number” cluster is attributed to the presence of a compact clathrate cage isomer produced upon ESI. Peptide studies are also presented in which specific and nonspecific solvation is observed for gramicidin S [GS + 2H]^(2+) (H_(2)O)_(n) (n = 0 to 26) and bradykinin [BK + 2H]^(2+) (H_(2)O)_(n) (n = 0 to 73), respectively. However in the case of substance P, [SP + 3H]^(3+), the results demonstrate that a compact dehydrated conformer population (resulting from the evaporative ESI process) can be kinetically trapped on the time scale of several milliseconds, even when an extended coil conformation is energetically favorable in the gas phase. Advisors/Committee Members: Russell, David H (advisor), Batteas, James D (committee member), Schweikert, Emile A (committee member), Musser, Siegfried M (committee member).

Subjects/Keywords: mass spectrometry; ion mobility spectrometry; periodic focusing ion guide; gas phase hydration

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APA (6^th Edition):

Silveira, J. A. (2013). Development of Ion Mobility-mass Spectrometry Instrumentation to Probe the Conformations and Capture the Solution to Gas Phase Transition of Electrosprayed Biomolecules. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/151729

Chicago Manual of Style (16^th Edition):

Silveira, Joshua A. “Development of Ion Mobility-mass Spectrometry Instrumentation to Probe the Conformations and Capture the Solution to Gas Phase Transition of Electrosprayed Biomolecules.” 2013. Doctoral Dissertation, Texas A&M University. Accessed March 04, 2021. http://hdl.handle.net/1969.1/151729.

MLA Handbook (7^th Edition):

Silveira, Joshua A. “Development of Ion Mobility-mass Spectrometry Instrumentation to Probe the Conformations and Capture the Solution to Gas Phase Transition of Electrosprayed Biomolecules.” 2013. Web. 04 Mar 2021.

Vancouver:

Silveira JA. Development of Ion Mobility-mass Spectrometry Instrumentation to Probe the Conformations and Capture the Solution to Gas Phase Transition of Electrosprayed Biomolecules. [Internet] [Doctoral dissertation]. Texas A&M University; 2013. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/1969.1/151729.

Council of Science Editors:

Silveira JA. Development of Ion Mobility-mass Spectrometry Instrumentation to Probe the Conformations and Capture the Solution to Gas Phase Transition of Electrosprayed Biomolecules. [Doctoral Dissertation]. Texas A&M University; 2013. Available from: http://hdl.handle.net/1969.1/151729

Texas A&M University

16. Pravitasari, Arika. Tuning the Optical Properties of Nanoscale Materials on Surfaces Through Controlled Exchange Reactions on Cadmium Selenide Quantum Dots and Patterning of Gold and QD Nanoparticle Arrays.

Degree: PhD, Chemistry, 2013, Texas A&M University

URL: http://hdl.handle.net/1969.1/151756

► This work focused on the integration of CdSe quantum dots (QDs) and Au nanoparticles (NPs) as building blocks for the development of quantum dot and… (more)

▼ This work focused on the integration of CdSe quantum dots (QDs) and Au nanoparticles (NPs) as building blocks for the development of quantum dot and plasmonic based optical and sensing devices. The manipulation of nanomaterials was performed to tune their surface and optical properties to study their fundamental chemical and physical processes as well as their applications. First, the cation exchange reactions between CdSe QDs and Ag+ cations were explored as the surface properties of the QDs were altered. The surface properties of CdSe QDs were tuned by local exposure of laser through photopatterning. The CdSe QDs with different surface properties altered by photopatterning were then exposed to a solution of increasing Ag+ concentrations. The decrease in the photoluminescence intensity of CdSe QDs were monitored and used as an indication for the cation exchange reactions taking place. Photoluminescence data confirmed that the cation exchange reactions exhibited different efficiencies for QDs that were photo-altered in comparison to pristine QDs. The second area of the study employed the use of directed assembly to fabricate pattern arrays of Au NPs. Fabrication of metallic nanostructure arrays using polystyrene (PS) microspheres often required the use of photo-resist, chemical etching and metal evaporation processes, here they were use to direct the assembly of colloidal Au nanoparticles (NPs) by simple evaporative processes. This created an inexpensive and simple bench-top method for bottom-up fabrication of metallic nanostructure arrays. Optimum parameter for the formation of uniform Au nanoring arrays was achieved by controlling the relative humidity (RH) and the relative concentration of Au NPs to PS microspheres. The fabricated Au nanostructure arrays serve as great platforms not only for future applications in plasmonic based sensing and optical devices but also for the fundamental studies of their localized surface plasmon resonance (LSPR). An alternative method of patterning, a combination between the use of a self-assembled monolayer (SAM) molecular linker and PS mask fabricated via polydimethylsiloxane (PDMS) micro-stamp was also discussed briefly. Particle lithography is a versatile method and can be used to fabricate pattern array of different nanomaterials with similar surface affinities. It was then modified to reduce the non-specific binding of CdSe QDs forming uniform nanoring arrays. The photoluminescence of the fabricated CdSe nanoring arrays was then altered to locally tune their surface and optical properties. This allowed for the post-fabrication surface modification of each nanoring for the creation of CdSe nanoring arrays of different surface and optical properties. Advisors/Committee Members: Batteas, James D (advisor), Son, Dong Hee (committee member), Schweikert, Emile A (committee member), Grunlan, Jaime (committee member).

Subjects/Keywords: CdSe quantum dots; cation exchange; Au nanoparticle arrays; particle lithography

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APA (6^th Edition):

Pravitasari, A. (2013). Tuning the Optical Properties of Nanoscale Materials on Surfaces Through Controlled Exchange Reactions on Cadmium Selenide Quantum Dots and Patterning of Gold and QD Nanoparticle Arrays. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/151756

Chicago Manual of Style (16^th Edition):

Pravitasari, Arika. “Tuning the Optical Properties of Nanoscale Materials on Surfaces Through Controlled Exchange Reactions on Cadmium Selenide Quantum Dots and Patterning of Gold and QD Nanoparticle Arrays.” 2013. Doctoral Dissertation, Texas A&M University. Accessed March 04, 2021. http://hdl.handle.net/1969.1/151756.

MLA Handbook (7^th Edition):

Pravitasari, Arika. “Tuning the Optical Properties of Nanoscale Materials on Surfaces Through Controlled Exchange Reactions on Cadmium Selenide Quantum Dots and Patterning of Gold and QD Nanoparticle Arrays.” 2013. Web. 04 Mar 2021.

Vancouver:

Pravitasari A. Tuning the Optical Properties of Nanoscale Materials on Surfaces Through Controlled Exchange Reactions on Cadmium Selenide Quantum Dots and Patterning of Gold and QD Nanoparticle Arrays. [Internet] [Doctoral dissertation]. Texas A&M University; 2013. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/1969.1/151756.

Council of Science Editors:

Pravitasari A. Tuning the Optical Properties of Nanoscale Materials on Surfaces Through Controlled Exchange Reactions on Cadmium Selenide Quantum Dots and Patterning of Gold and QD Nanoparticle Arrays. [Doctoral Dissertation]. Texas A&M University; 2013. Available from: http://hdl.handle.net/1969.1/151756

Texas A&M University

17. Gamez, Roberto. Development of and Application of Plasmonic Nanomaterials for Mass Spectrometry Based Biosensing.

Degree: PhD, Chemistry, 2014, Texas A&M University

URL: http://hdl.handle.net/1969.1/152818

► The use of nanomaterials for sensing and biological applications has recently gained interest owing to the unique physical, chemical and optical properties that arise when… (more)

▼ The use of nanomaterials for sensing and biological applications has recently gained interest owing to the unique physical, chemical and optical properties that arise when materials are reduced to the nanoscale. The unique optical properties exhibited by gold (Au) and silver (Ag) nanomaterials have made for versatile platforms in a wide range of applications including surface plasmon biosensing techniques and laser desorption/ionization mass spectrometry (LDI-MS). A primary driver for this work is the relative ease performing surface modifications to nanoparticles (NPs), which can be used to enhance the selectivity of ionization and/or facilitate analyte capture. The research presented here focuses on the development of AuNP and AgNP based biosensors for selective capture and ionization of low abundance compounds from complex mixtures and subsequent detection by LDI-MS and Matrix Assisted Laser Desorption Ionization- Mass Spectrometry (MALDI-MS). First, a ‘strategy’ for selective capture and ionization of specific compound classes based on chemical derivatization of gold nanorods (AuNRs) and infrared laser desorption ionization (IR-LDI) is described. LDI is performed at near infrared wavelengths (1064 nm) that overlap with the longitudinal surface plasmon resonance (LSPR) mode of AuNRs which allows absorbed energy from the laser to facilitate the desorption and ionization of the analyte. Capture of hydrophobic species using surfactant coated AuNRs and subsequent detection by IR-LDI-MS was also demonstrated in these experiments. Second, the fabrication of a label-free MS and optical detection based biosensor platform consisting of a phospholipid layer partially tethered to the surface of a gold nanorod for the detection of low abundance lipophilic analytes from complex mixtures is described. In these experiments, stable phospholipid capped AuNRs are produced by tethering some of the phospholipids to the surface of the AuNRs though a covalent, gold-thiol linkage. The effectiveness of the biosensor is demonstrated for the label-free detection of a membrane active lipophilic drug from aqueous solution and of a lipopeptide from fetal bovine serum. Lastly, porous AgNP embedded thin films were fabricated by the sol-gel method and utilized as matrix-free LDI-MS biosensors applicable to several chemical classes. In these experiments, UV laser irradiation (337 nm) of the AgNP facilitates desorption and ionization of a number of peptides, triglycerides, and phospholipids. Preferential ionization of sterols from vesicles composed of olefinic phosphosphatidylcholines is also demonstrated. Advisors/Committee Members: Russell, David H (advisor), Batteas, James D (committee member), Schweikert, Emile A (committee member), Pellois, Jean-Phillipe (committee member).

Subjects/Keywords: Mass Spectrometry; Gold Nanorods; Gold Nanoparticles; Sol-Gel; Silver Nanoparticles

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APA (6^th Edition):

Gamez, R. (2014). Development of and Application of Plasmonic Nanomaterials for Mass Spectrometry Based Biosensing. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/152818

Chicago Manual of Style (16^th Edition):

Gamez, Roberto. “Development of and Application of Plasmonic Nanomaterials for Mass Spectrometry Based Biosensing.” 2014. Doctoral Dissertation, Texas A&M University. Accessed March 04, 2021. http://hdl.handle.net/1969.1/152818.

MLA Handbook (7^th Edition):

Gamez, Roberto. “Development of and Application of Plasmonic Nanomaterials for Mass Spectrometry Based Biosensing.” 2014. Web. 04 Mar 2021.

Vancouver:

Gamez R. Development of and Application of Plasmonic Nanomaterials for Mass Spectrometry Based Biosensing. [Internet] [Doctoral dissertation]. Texas A&M University; 2014. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/1969.1/152818.

Council of Science Editors:

Gamez R. Development of and Application of Plasmonic Nanomaterials for Mass Spectrometry Based Biosensing. [Doctoral Dissertation]. Texas A&M University; 2014. Available from: http://hdl.handle.net/1969.1/152818

Texas A&M University

18. Ewers, Bradley William. Geometric Nanoconfinement Effects on the Electronic and Mechanical Properties of Self-Assembled Molecular Systems.

Degree: PhD, Chemistry, 2014, Texas A&M University

URL: http://hdl.handle.net/1969.1/153823

► With the ongoing research and development of nanoscale technologies and materials, it becomes increasingly important to understand how local environment influences molecular and material properties.… (more)

▼ With the ongoing research and development of nanoscale technologies and materials, it becomes increasingly important to understand how local environment influences molecular and material properties. An important factor in this regard is geometric nanoconfinement, for example, the restriction of molecules to nanostructure surfaces. The bulk or average characteristics of materials and molecules do not appropriately define their behavior in these circumstances, and highly localized measurement techniques developed to specifically identify the influence of confinement on their properties is essential to understanding their characteristics and behavior. In this dissertation, two forms of geometric confinement are considered in the context of different molecular properties. First, the role of radial confinement on the tribological properties of self-assembled monolayers (SAMs) is considered. SAMs are an excellent model lubricant for experimental studies of boundary lubrication, and they have been employed as boundary lubricant additives and surface coatings. The lubricated contacts of technologically relevant surfaces, however, consist of asperity interactions, and the summit curvature of these asperities can impact the critical cohesive forces from which the properties of the SAM are derived. Molecular dynamics simulation was employed to understand the influence of nanoscopic surface curvature, as well as surface coverage density, two factors which together contribute to the cohesive forces of SAMs, on their tribological properties. In particular their dissipative potential and effective surface protection were examined, as well as the influence of these factors on the contact mechanics of functionalized nanoasperity contacts. Another mode of geometric confinement studiedin this work is two-dimensional nanoconfinement of molecules and its influence on the mechanism of charge transport in molecular systems. Effective control of charge transport in molecules is essential for molecular modification of CMOS technologies, and is critical in controlling charge carrier dynamics in dye-sensitized photovoltaics. In this work, the size dependence of the electronic properties of thiol-tethered zinc porphyrin aggregateson the Au(111) surface was investigated. AFM nanolithography was used to confine these molecules within an alkanethiol matrix on the Au(111) surface, forming molecular islands of specific dimensions to investigate the relationship between island size and charge transport, demonstrating a shift from tunneling based charge transport to the more tunable and efficient charge hopping based transport. Advisors/Committee Members: Batteas, James D (advisor), Wooley, Karen L (committee member), Wheeler, Steven E (committee member), Polycarpou, Andreas A (committee member).

Subjects/Keywords: tribology; charge transport; porphyrin; molecular dynamics; scanning tunneling microscopy; atomic force microscopy; nanolithography

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APA (6^th Edition):

Ewers, B. W. (2014). Geometric Nanoconfinement Effects on the Electronic and Mechanical Properties of Self-Assembled Molecular Systems. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/153823

Chicago Manual of Style (16^th Edition):

Ewers, Bradley William. “Geometric Nanoconfinement Effects on the Electronic and Mechanical Properties of Self-Assembled Molecular Systems.” 2014. Doctoral Dissertation, Texas A&M University. Accessed March 04, 2021. http://hdl.handle.net/1969.1/153823.

MLA Handbook (7^th Edition):

Ewers, Bradley William. “Geometric Nanoconfinement Effects on the Electronic and Mechanical Properties of Self-Assembled Molecular Systems.” 2014. Web. 04 Mar 2021.

Vancouver:

Ewers BW. Geometric Nanoconfinement Effects on the Electronic and Mechanical Properties of Self-Assembled Molecular Systems. [Internet] [Doctoral dissertation]. Texas A&M University; 2014. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/1969.1/153823.

Council of Science Editors:

Ewers BW. Geometric Nanoconfinement Effects on the Electronic and Mechanical Properties of Self-Assembled Molecular Systems. [Doctoral Dissertation]. Texas A&M University; 2014. Available from: http://hdl.handle.net/1969.1/153823

Texas A&M University

19. Liu, Chunming. Protein Separation and Label-Free Detection on Supported Lipid Bilayers.

Degree: PhD, Chemistry, 2012, Texas A&M University

URL: http://hdl.handle.net/1969.1/ETD-TAMU-2012-08-11754

► Membrane-bound proteins and charged lipids are separated based on their charge-to-size ratio by electrophoretic-electroosmotic focusing (EEF) method on supported lipid bilayers (SLBs). EEF uses opposing… (more)

▼ Membrane-bound proteins and charged lipids are separated based on their charge-to-size ratio by electrophoretic-electroosmotic focusing (EEF) method on supported lipid bilayers (SLBs). EEF uses opposing electrophoretic and electroosmotic forces to focus and separate proteins and lipids into narrow bands from an initially homogeneous mixture. Membrane-associated species were focused into specific positions within the SLB in a highly repeatable fashion. The steady-state focusing positions of the proteins could be predicted and controlled by tuning experimental conditions, such as buffer pH, ionic strength, electric field and temperature. Careful tuning of the variables should enable one to separate mixtures of membrane proteins with only subtle differences. The EEF technique was found to be an effective way to separate protein mixtures with low initial concentrations and it overcame diffusive peak broadening problem. A "SLB differentiation" post-separation SLB treatment method was also developed by using magnetic particles to rapidly slice the whole SLB into many small patches after electrophoretic separation, while keeping the majority of materials on surface and avoiding the use of chemical reactions. Label-free detection techniques were also developed based on EEF on SLBs. First, a new separation based label-free detection method was developed based on the change of focusing position of fluorescently labeled ligands. This technique is capable of simultaneous detecting multiple protein competitive binding on the same ligand on SLBs. Low concentration protein can be detected in the presence of interfering proteins and high concentration of BSA. The fluorescent ligands were moved to different focusing positions in a charged SLB patch by different binding proteins. Both free ligand and protein bound ligand concentrations were obtained. Therefore, both protein identity and quantity information were obtained simultaneously. Second, the focusing position of fluorescent biomarkers on SLB was used to monitor the phospholipase D catalyzed hydrolysis of phosphatidylcholine (PC) to form phosphatidic acid (PA), which is involved with the change of charge on the phospholipids. The focusing position of fluorescent membrane-bound biomarker in the EEF experiment is directly determined by the negative charge density on SLB. Other enzyme reactions involved with the change of phospholipids charge can be monitored in a label-free fashion in a similar way. Advisors/Committee Members: Cremer, Paul S. (advisor), Batteas, James D. (committee member), Hilty, Christian (committee member), Musser, Siegfried M. (committee member).

Subjects/Keywords: Supported Lipid Bilayer; Electrophoretic-Electroosmotic Focusing; Protein Separation; Label-Free Detection

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APA (6^th Edition):

Liu, C. (2012). Protein Separation and Label-Free Detection on Supported Lipid Bilayers. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2012-08-11754

Chicago Manual of Style (16^th Edition):

Liu, Chunming. “Protein Separation and Label-Free Detection on Supported Lipid Bilayers.” 2012. Doctoral Dissertation, Texas A&M University. Accessed March 04, 2021. http://hdl.handle.net/1969.1/ETD-TAMU-2012-08-11754.

MLA Handbook (7^th Edition):

Liu, Chunming. “Protein Separation and Label-Free Detection on Supported Lipid Bilayers.” 2012. Web. 04 Mar 2021.

Vancouver:

Liu C. Protein Separation and Label-Free Detection on Supported Lipid Bilayers. [Internet] [Doctoral dissertation]. Texas A&M University; 2012. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2012-08-11754.

Council of Science Editors:

Liu C. Protein Separation and Label-Free Detection on Supported Lipid Bilayers. [Doctoral Dissertation]. Texas A&M University; 2012. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2012-08-11754

Texas A&M University

20. Chang, Chi-Yuan 1980-. Electrical and Optical Characterization of Nanoscale Materials for Electronics.

Degree: PhD, Chemistry, 2012, Texas A&M University

URL: http://hdl.handle.net/1969.1/148119

► Due to a lack of fundamental knowledge about the role of molecular structures in molecular electronic devices, this research is focused on the development of… (more)

▼ Due to a lack of fundamental knowledge about the role of molecular structures in molecular electronic devices, this research is focused on the development of instruments to understand the relation between device design and the electronic properties of electroactive components. The overall goal is to apply this insight to obtain a more efficient and reliable scheme and greater functional control over each component. This work developed a fabrication method for porphyrinoids on graphene-based field effect transistors (FETs), and a chemical sensing platform under an ambient environment by integrating a tip-enhanced Raman spectroscope (TERS), atomic force microscope (AFM), and electronic testing circuit. The study is divided into three aspects. The first is aimed at demonstrating fabrication processes of nanoscale FETs of graphene and porphyrinoid composites based entirely on scanning probe lithography (SPL). A nanoshaving mechanism was used to define patterns on octadecanethiol self-assembled monolayers on gold film evaporated on graphene flakes, followed by metal wet etching and/or oxygen plasma etching to develop patterns on Au films and graphene, respectively. The integrity and optoelectronic properties were examined to validate the processes. The second area of study focused on the development of the chemical sensing platform, enabling chemical changes to be monitored during charge transports under an ambient environment. The localized Raman enhancement was induced by exciting surface plasmon resonance in nanoscale silver enhancing probes made by thermal silver evaporation on sharp AFM tips. As the system was designed along an off-axis illumination/collection scheme, it was demonstrated that it was capable of observing molecular decomposition on opaque and conductive substrates induced by an electric bias. The third line of work proposed a novel TERS system and a probe preparation method. Silver nanowires mounted on AFM tips were used to locally enhance the Raman scattering. The observed Raman enhancement allows quick chemical analysis from a nanoscale region, and thus enables chemical mapping beyond the diffraction limit. Compared with other TERS geometries, the new optical design not only allows analysis on large or opaque samples, but also simplifies the design of the optical components and the alignment processes of the setup. Advisors/Committee Members: Batteas, James D (advisor), Son, Dong Hee (committee member), Liang, Hong (committee member), Cremer, Paul S (committee member).

Subjects/Keywords: Nanowire; Nanolithography; FET; TERS; Tip-enhanced Raman; Graphene

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APA (6^th Edition):

Chang, C. 1. (2012). Electrical and Optical Characterization of Nanoscale Materials for Electronics. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/148119

Chicago Manual of Style (16^th Edition):

Chang, Chi-Yuan 1980-. “Electrical and Optical Characterization of Nanoscale Materials for Electronics.” 2012. Doctoral Dissertation, Texas A&M University. Accessed March 04, 2021. http://hdl.handle.net/1969.1/148119.

MLA Handbook (7^th Edition):

Chang, Chi-Yuan 1980-. “Electrical and Optical Characterization of Nanoscale Materials for Electronics.” 2012. Web. 04 Mar 2021.

Vancouver:

Chang C1. Electrical and Optical Characterization of Nanoscale Materials for Electronics. [Internet] [Doctoral dissertation]. Texas A&M University; 2012. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/1969.1/148119.

Council of Science Editors:

Chang C1. Electrical and Optical Characterization of Nanoscale Materials for Electronics. [Doctoral Dissertation]. Texas A&M University; 2012. Available from: http://hdl.handle.net/1969.1/148119

Texas A&M University

21. Cummins, Kyle. Interfacial Properties of Ultrathin- Film Metal Electrodes: Studies by Combined Electron Spectroscopy and Electrochemistry.

Degree: PhD, Chemistry, 2012, Texas A&M University

URL: http://hdl.handle.net/1969.1/ETD-TAMU-2012-05-11199

► A pair of studies investigating the deposition and surface chemical properties of ultrathin metal films were pursued: (i) Pt-Co alloys on Mo(110); and (ii) Pd… (more)

▼ A pair of studies investigating the deposition and surface chemical properties of ultrathin metal films were pursued: (i) Pt-Co alloys on Mo(110); and (ii) Pd on Pt(111). Experimental measurement was based on a combination of electron spectroscopy (low energy ion scattering spectroscopy, X-ray photoelectron spectroscopy, Auger electron spectroscopy, and low energy electron diffraction) and electrochemistry (voltage efficiency, voltammetry, and coulometry). Mixed-metal preparation of Pt-Co films by thermal vapor deposition (TVD) resulted in a thin-film binary alloy. Careful analysis revealed a substantial divergence between the composition at the interface and that in the interior. This outcome was observed for all compositions and allowed for the construction of a ?surface phase diagram?. The proclivities of the alloys of pre-selected compositions towards enhanced catalysis of the oxygen-reduction reaction were assessed in terms of their voltage efficiencies, as manifested by the open-circuit potential (OCP) in O2-saturated dilute sulfuric acid electrolyte. The particular alloy surface, Pt3Co (XPt=3,XCo=1), whether from the thin film or a bulk single crystal, exhibited the highest OCP, a significant improvement over pure Pt but still appreciably lower than the thermodynamic limit. Under test conditions, the degradation of thusly-prepared films was primarily due to Co corrosion. Ultrathin Pd films on well-defined Pt(111) surfaces, with coverages from 0.5 to 8 monolayers (ML), were prepared by surface-limited redox replacement reaction (galvanic exchange) of underpotentially deposited Cu. Spectroscopic data revealed that films prepared in this manner are elementally pure, pseudomorphic to the substrate, and stable, independent of the surface coverage (?) of palladium. Analysis of the voltammetric profiles in the hydrogen evolution region revealed unique properties of hydrogen adsorption unseen in bulk electrodes. Notably, at 1 ML coverage, a step-free film was produced that did not exhibit hydrogen absorption. At higher coverages, digital (layer-by-layer) deposition gave way to 3D islands in a Stranski- Krastanov growth mode; under these conditions, onset of bulk-like behavior was observed. This method makes possible the synthesis of well-ordered noble-metal films in the absence of high-temperature treatment Advisors/Committee Members: Soriaga, Manuel P. (advisor), Vigh, Gyula (committee member), Batteas, James D. (committee member), Zhang, Xinghang (committee member).

Subjects/Keywords: UHV-EC; interfacial electrochemistry; platinum; cobalt; Pt-Co; thin films; alloys; Pt(111); ORR; UPD; galvanic displacement; SLR3; surface limited redox replacement reaction

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APA (6^th Edition):

Cummins, K. (2012). Interfacial Properties of Ultrathin- Film Metal Electrodes: Studies by Combined Electron Spectroscopy and Electrochemistry. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2012-05-11199

Chicago Manual of Style (16^th Edition):

Cummins, Kyle. “Interfacial Properties of Ultrathin- Film Metal Electrodes: Studies by Combined Electron Spectroscopy and Electrochemistry.” 2012. Doctoral Dissertation, Texas A&M University. Accessed March 04, 2021. http://hdl.handle.net/1969.1/ETD-TAMU-2012-05-11199.

MLA Handbook (7^th Edition):

Cummins, Kyle. “Interfacial Properties of Ultrathin- Film Metal Electrodes: Studies by Combined Electron Spectroscopy and Electrochemistry.” 2012. Web. 04 Mar 2021.

Vancouver:

Cummins K. Interfacial Properties of Ultrathin- Film Metal Electrodes: Studies by Combined Electron Spectroscopy and Electrochemistry. [Internet] [Doctoral dissertation]. Texas A&M University; 2012. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2012-05-11199.

Council of Science Editors:

Cummins K. Interfacial Properties of Ultrathin- Film Metal Electrodes: Studies by Combined Electron Spectroscopy and Electrochemistry. [Doctoral Dissertation]. Texas A&M University; 2012. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2012-05-11199

Texas A&M University

22. Zhou, Zihao. Scanning Tunneling Microscopy Studies of Metal Clusters Supported on Graphene and Silica Thin Film.

Degree: PhD, Chemistry, 2012, Texas A&M University

URL: http://hdl.handle.net/1969.1/ETD-TAMU-2012-08-11409

► The understanding of nucleation and growth of metals on a planar support at the atomic level is critical for both surface science research and heterogeneous… (more)

▼ The understanding of nucleation and growth of metals on a planar support at the atomic level is critical for both surface science research and heterogeneous catalysis studies. In this dissertation, two planar substrates, including graphene and ultra-thin silica film were employed for supported model catalysts studies. The structure and stability of several catalytically important metals supported on these two substrates were thoroughly investigated using scanning tunneling microscopy (STM) coupled with other traditional surface science techniques. In the study of the graphene/Ru(0001) system, the key factors that govern the growth and distribution of metals on the graphene have been studied based on different behaviors of five transition metals, namely Pt, Rh, Pd, Co, and Au supported on the template of a graphene moire pattern formed on Ru(0001). Both metal-carbon (M-C) bond strength and metal cohesive energies play significant roles in the cluster formation process and the M-C bond strength is the most important factor that affects the morphology of clusters at the initial stages of growth. Interestingly, Au exhibits two-dimensional (2-D) structures that span several moire unit cells. Preliminary data obtained by dosing molecular oxygen onto CO pre-covered Au islands suggest that the 2-D Au islands catalyze the oxidation of CO. Moreover, graphene/Ru(0001) system was modified by introducing transition metals, oxygen or carbon at the interface between the graphene and Ru(0001). Our STM results reveal that the geometric and/or electronic structure of graphene can be adjusted correspondingly. In the study of the silica thin film system, the structure of silica was carefully investigated and our STM images favor for the [SiO4] cluster model rather than the network structure. The nucleation and adsorption of three metals, namely Rh, Pt and Pd show that the bond strength between the metal atom and Si is the key factor that determines the nucleation sites at the initial stages of metal deposition. The annealing effect studies reveal that Rh and Pt atoms diffuse beneath the silica film and form the 2-D islands that are covered with a silica thin film. In contrast, the formation of Pd silicide was observed upon annealing to high temperatures. Advisors/Committee Members: Goodman, David W. (advisor), Batteas, James D. (advisor), Agnolet, Glenn (committee member), Lucchese, Robert R. (committee member).

Subjects/Keywords: STM; Graphene; Silica Film; Metal Clusters; Au

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APA (6^th Edition):

Zhou, Z. (2012). Scanning Tunneling Microscopy Studies of Metal Clusters Supported on Graphene and Silica Thin Film. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2012-08-11409

Chicago Manual of Style (16^th Edition):

Zhou, Zihao. “Scanning Tunneling Microscopy Studies of Metal Clusters Supported on Graphene and Silica Thin Film.” 2012. Doctoral Dissertation, Texas A&M University. Accessed March 04, 2021. http://hdl.handle.net/1969.1/ETD-TAMU-2012-08-11409.

MLA Handbook (7^th Edition):

Zhou, Zihao. “Scanning Tunneling Microscopy Studies of Metal Clusters Supported on Graphene and Silica Thin Film.” 2012. Web. 04 Mar 2021.

Vancouver:

Zhou Z. Scanning Tunneling Microscopy Studies of Metal Clusters Supported on Graphene and Silica Thin Film. [Internet] [Doctoral dissertation]. Texas A&M University; 2012. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2012-08-11409.

Council of Science Editors:

Zhou Z. Scanning Tunneling Microscopy Studies of Metal Clusters Supported on Graphene and Silica Thin Film. [Doctoral Dissertation]. Texas A&M University; 2012. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2012-08-11409

Texas A&M University

23. Spear, Jessica. Understanding and Controlling the Tribological Properties of Graphene on Rough Surfaces.

Degree: PhD, Chemistry, 2015, Texas A&M University

URL: http://hdl.handle.net/1969.1/156401

► Understanding and controlling friction, adhesion and wear is critical for the continued growth and utilization of emerging nanotechnologies such as micro- and nano-electromechanical systems devices… (more)

▼ Understanding and controlling friction, adhesion and wear is critical for the continued growth and utilization of emerging nanotechnologies such as micro- and nano-electromechanical systems devices (NEMS/MEMS). The challenge of operating NEMS/MEMS with contacting interfaces stems from the large surface-to-volume ratio of these devices where surface forces dominate the interfacial interactions. Capillary forces, even in low humidity, can increase adhesion causing high friction and sticking as well as catalyzing wear on the surface. In addition, the nanoscale roughness of surfaces leads to high pressures and shear forces at asperity-asperity contacts, ultimately leading to device failure. To mitigate friction and wear of silicon surfaces, two-dimensional solid state lubricants such as graphene have drawn increased interest due to the rapid development of fabrication techniques. One of the newest carbon nanomaterials, graphene is a single atomic layer of highly ordered pyrolytic graphite. Studies over the past decade on graphene have elucidated a variety of unique properties such as large out-of-plane flexibility, strong in-plane modulus and chemical inertness which have made it an ideal candidate for use as a protective surface coating. Although graphene can easily adopt a similar morphology to its underlying substrate, the properties of graphene are largely influenced by its environmental and substrate interactions. To better understand and address the challenges of graphene’s substrate mediated properties for applications to NEMS/MEMS, this dissertation includes research on the fundamental interactions between graphene and rough substrates. Using Atomic Force Microscopy, the morphology of graphene on rough surfaces was shown to partially conform to the substrate roughness as a result of the size and spacing of the nanoparticle asperities and a balance between the interfacial adhesion and strain in the graphene lattice. This type of morphology decreases the contact between graphene and the substrate resulting in a weakly bound state that is undesirable for use as a protective coating. However, exploring the mechanical properties showed that under increased loading the conformity could be controllably increased and the frictional properties showed a dependence on the asperity-asperity contact area unique to these types of rough substrate geometries. Based on these results, further research was explored to control the tribological properties of graphene by systematically changing the nanoscale roughness and surface chemistry to increase graphene adhesion to the substrate for better friction modification. Advisors/Committee Members: Batteas, James D (advisor), Son, Dong H (committee member), Grunla, Jaime C (committee member), Schweikert, Emile A (committee member).

Subjects/Keywords: Graphene; Friction; AFM

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APA (6^th Edition):

Spear, J. (2015). Understanding and Controlling the Tribological Properties of Graphene on Rough Surfaces. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/156401

Chicago Manual of Style (16^th Edition):

Spear, Jessica. “Understanding and Controlling the Tribological Properties of Graphene on Rough Surfaces.” 2015. Doctoral Dissertation, Texas A&M University. Accessed March 04, 2021. http://hdl.handle.net/1969.1/156401.

MLA Handbook (7^th Edition):

Spear, Jessica. “Understanding and Controlling the Tribological Properties of Graphene on Rough Surfaces.” 2015. Web. 04 Mar 2021.

Vancouver:

Spear J. Understanding and Controlling the Tribological Properties of Graphene on Rough Surfaces. [Internet] [Doctoral dissertation]. Texas A&M University; 2015. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/1969.1/156401.

Council of Science Editors:

Spear J. Understanding and Controlling the Tribological Properties of Graphene on Rough Surfaces. [Doctoral Dissertation]. Texas A&M University; 2015. Available from: http://hdl.handle.net/1969.1/156401

Texas A&M University

24. Alvarez Ortiz, Johannes Orlando. Wettability Alteration Using Surfactants to Improve Oil Recovery from Unconventional Liquid Reservoirs.

Degree: PhD, Petroleum Engineering, 2017, Texas A&M University

URL: http://hdl.handle.net/1969.1/165825

► Improving oil recovery from unconventional liquid reservoirs (ULR) is a major challenge, and knowledge of recovery mechanisms and interaction of completion fluid additives with the… (more)

▼ Improving oil recovery from unconventional liquid reservoirs (ULR) is a major challenge, and knowledge of recovery mechanisms and interaction of completion fluid additives with the rock is fundamental in tackling the problem. Fracture treatment performance and consequently oil recovery could be improved by adding surfactants to stimulation fluids to promote imbibition by wettability alteration and interfacial tension (IFT) reduction. The Young-Laplace equation relates the capillary pressure to IFT and contact angle. Thus, it follows that capillarity is significant in nanopores associated with ULR and complex as the contact angle (CA) and IFT varies simultaneously. This study analyzes the potential of improving oil recovery by imbibition using different groups of surfactants as additives to completion fluids by characterizing their interaction with oil and heterogeneous siliceous and carbonate ULR samples from the Wolfcamp, Eagle Ford, Bakken and Barnet formations as well as the effect of wettability modification and IFT reduction in maximizing well performance after stimulation. A correlated set of experiments were proposed beginning by characterizing ULR rocks and fluids and evaluating original wettability by measuring CA and zeta-potential. Then, different types of surfactants were evaluated to gauge their effectiveness in altering wettability and IFT. In addition, adsorption measurements were performed to calculate the amount of surfactant adsorbed into the rock. Moreover, spontaneous imbibition experiments were carried out in conjunction with CT scan technology to measure oil recovery, fluid penetration (imbibition) and change of fluid saturation in the rock samples with time. Then, a core-flooding system was designed to be combined with the CT scanner to experimentally simulate the fracture-treatment and to represent surfactant imbibition in an ULR core fracture during a soaking and flowback production scheme. The results showed that surfactant solutions are capable of altering ULR wettability to water-wet with moderate reduction of IFT. However, the extent of wettability alteration strongly depends on rock lithology, surfactant and oil type. Surfactant adsorption measurements also showed the dependence of rock lithology on surfactant performance. Moreover, spontaneous imbibition and core-flooding experiments suggested that wettability alteration and IFT reduction are beneficial to oil recovery as evidenced by the improved oil recovery when surfactants were used. These findings were consistent with CA, zeta potential, surfactant adsorption and IFT measurements. Next, to scale our laboratory results, imbibition rates and dimensionless time scaling curves were generated corroborating that fracture density and rock-fluid interactions are key parameters for oil recovery. From the results obtained, it can be concluded that moderate IFT reduction in addition to significant wettability alteration has optimum effect on improving oil recovery from these ULR. These findings provide insight in designing completion… Advisors/Committee Members: Schechter, David S (advisor), Barrufet, Maria A (committee member), Akkutlu, Ibrahim Y (committee member), Batteas, James D (committee member).

Subjects/Keywords: Wettability; Unconventional Liquid Reservoirs; Surfactants; Imbibition; Shale; Wolfcamp; Eagle Ford; Bakken; Barnett

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APA (6^th Edition):

Alvarez Ortiz, J. O. (2017). Wettability Alteration Using Surfactants to Improve Oil Recovery from Unconventional Liquid Reservoirs. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/165825

Chicago Manual of Style (16^th Edition):

Alvarez Ortiz, Johannes Orlando. “Wettability Alteration Using Surfactants to Improve Oil Recovery from Unconventional Liquid Reservoirs.” 2017. Doctoral Dissertation, Texas A&M University. Accessed March 04, 2021. http://hdl.handle.net/1969.1/165825.

MLA Handbook (7^th Edition):

Alvarez Ortiz, Johannes Orlando. “Wettability Alteration Using Surfactants to Improve Oil Recovery from Unconventional Liquid Reservoirs.” 2017. Web. 04 Mar 2021.

Vancouver:

Alvarez Ortiz JO. Wettability Alteration Using Surfactants to Improve Oil Recovery from Unconventional Liquid Reservoirs. [Internet] [Doctoral dissertation]. Texas A&M University; 2017. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/1969.1/165825.

Council of Science Editors:

Alvarez Ortiz JO. Wettability Alteration Using Surfactants to Improve Oil Recovery from Unconventional Liquid Reservoirs. [Doctoral Dissertation]. Texas A&M University; 2017. Available from: http://hdl.handle.net/1969.1/165825

Texas A&M University

25. Parobek, David G. Transition Metal Doping of Semiconductor Quantum Dots for Enhanced Hot Electron Generation Under Visible Excitation.

Degree: PhD, Chemistry, 2020, Texas A&M University

URL: http://hdl.handle.net/1969.1/192456

► Hot charge carrier generation and extraction from semiconducting and metal nanoparticle materials have been heavily researched from their potential to preform chemistry that regular electrons… (more)

▼ Hot charge carrier generation and extraction from semiconducting and metal nanoparticle materials have been heavily researched from their potential to preform chemistry that regular electrons are not capable of. One major hurdle that inhibits the practical use of hot electrons is the need for high energy photons or high photon fluxes for their generation in most semiconductors, which is not readily available through solar radiation. Noble metal nanoparticles are able to generate hot electrons under visible radiation but due to the low relative energy of the hot electrons their use for jumping over energetic barriers and photocatalysis is limited. Colloidal semiconductor nanocrystals have been at the forefront of nanoscience research from the wide range of interesting properties that are imparted on them from quantum confinement effects that result in new physical processes when compared to their bulk counterparts. The promising optical properties of these materials with high quantum yields and photostability has made them useful in biological, photovoltaic, photocatalytic, and optoelectronic applications. In 3-dimensional confined quantum dots, the excitonic wavefunction can extend throughout the volume of the structure yielding greater sensitivity to the addition of dopants, further increasing the ability to manipulate the optical properties. Doping Mn in II-VI quantum dots has been of interest from the many optical and magnetic properties that it imparts on the host structure. The ⁴T₁ – ⁶A₁ transition has a low probability to occur from its small cross section due to its spin forbidden nature, relying on energy transfer from the host structure. The forbidden nature of this transition results in long millisecond photoluminescence lifetimes. The long lifetime of the Mn excited state is able to facilitate hot electron generation under low intensity cw excitation via two photon upconversion. This process occurs as follows: the first photon creates an exciton that has energy transfer to the Mn followed by another exciton being formed which the Mn undergoes back energy transfer excited state electron 2 eV further into the conduction band. The hot electrons generated in this have the ability to outcompete regular electrons in photocatalysis, the ability to be photoemitted from the quantum dot, and pass through an insulating barrier. While these results show the capability of hot electrons, the hot electron generation efficiency is still low which creates the need to explore new material systems that have higher inherent quantum yields to better facilitate this process. To circumvent this issue, cesium lead halide perovskite nanocrystals, which have photoluminescence quantum yields near unity, were explored as new material system for hot electron generation. The synthetic background for Mn doping in CsPbCl₃ and CsPbBr₃ was developed which will allow for the verification and study of the hot electron generation for this material. A new photoinduced anion exchange method was also developed which can allow for greater… Advisors/Committee Members: Son, Dong Hee (advisor), Batteas, James D (committee member), Sheldon, Matthew (committee member), Grunlan, Jamie (committee member).

Subjects/Keywords: Hot electron; Semiconductor Quantum Dots; Photocatalysis

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APA (6^th Edition):

Parobek, D. G. (2020). Transition Metal Doping of Semiconductor Quantum Dots for Enhanced Hot Electron Generation Under Visible Excitation. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/192456

Chicago Manual of Style (16^th Edition):

Parobek, David G. “Transition Metal Doping of Semiconductor Quantum Dots for Enhanced Hot Electron Generation Under Visible Excitation.” 2020. Doctoral Dissertation, Texas A&M University. Accessed March 04, 2021. http://hdl.handle.net/1969.1/192456.

MLA Handbook (7^th Edition):

Parobek, David G. “Transition Metal Doping of Semiconductor Quantum Dots for Enhanced Hot Electron Generation Under Visible Excitation.” 2020. Web. 04 Mar 2021.

Vancouver:

Parobek DG. Transition Metal Doping of Semiconductor Quantum Dots for Enhanced Hot Electron Generation Under Visible Excitation. [Internet] [Doctoral dissertation]. Texas A&M University; 2020. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/1969.1/192456.

Council of Science Editors:

Parobek DG. Transition Metal Doping of Semiconductor Quantum Dots for Enhanced Hot Electron Generation Under Visible Excitation. [Doctoral Dissertation]. Texas A&M University; 2020. Available from: http://hdl.handle.net/1969.1/192456

26. Bellido Sosa, Edson. Computational Study of the Development of Graphene Based Devices.

Degree: MS, Materials Science and Engineering, 2012, Texas A&M University

URL: http://hdl.handle.net/1969.1/ETD-TAMU-2011-12-10396

► Graphene is a promising material for many technological applications. To realize these applications, new fabrication techniques that allow precise control of the physical properties, as… (more)

▼ Graphene is a promising material for many technological applications. To realize these applications, new fabrication techniques that allow precise control of the physical properties, as well as large scale integration between single devices are needed. In this work, a series of studies are performed in order to develop graphene based devices. First, using MD simulations we study the effects of irradiating graphene with a carbon ion atom at several positions and energies from 0.1 eV to 100 keV. The simulations show four types of processes adsorption, reflection, transmission, and vacancy formation. At energies below 10 eV the dominant process is reflection, between 10 and 100 eV is adsorption, and between 100 eV and 100 keV the dominant process is transmission. Vacancy formation is a low rate process that takes place at energies above 30 eV. Three types of defects were found: adatom, single vacancy, and 5-8-5 defect formed from a double vacancy defect. Also a bottom-up fabrication method is studied, in this method, the controlled folding of graphene structures, driven by molecular interactions with water nanodroplets, is analyzed considering the interactions with substrates such as SiO2, HMDS and IPA on SiO2. When the graphene is supported on SiO2, the attraction between graphene and the substrate prevents graphene from folding but if the substrate has HMDS or IPA, the interaction between graphene and the substrate is weak, and depending on the geometry of the graphene structure, folding is possible. Finally, to evaluate the characteristics of graphene based devices, we model the vibrational bending modes of graphene ribbons with different dimensions. The resonant frequencies of the ribbons and relations between the size of the ribbon and their resonant frequencies are calculated. The interaction of a graphene vibronic device with water and IPA molecules are simulated and demonstrate that this device can be used as a sensitive vibronic molecular sensor that is able to distinguish the chemical nature of the detected molecule. Also, the electrical properties of the graphene vibronic with armchair and zigzag border are calculated; the latter has the potential to generate THz electrical signals as demonstrated in this work. Advisors/Committee Members: Seminario, Jorge M. (advisor), Balbuena, Perla B. (committee member), Batteas, James D. (committee member).

Subjects/Keywords: graphene; THz; vibronics; electronics; folding; ion bombardment; lithography; sensor; TeraHertz; defects; devices

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APA (6^th Edition):

Bellido Sosa, E. (2012). Computational Study of the Development of Graphene Based Devices. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2011-12-10396

Chicago Manual of Style (16^th Edition):

Bellido Sosa, Edson. “Computational Study of the Development of Graphene Based Devices.” 2012. Masters Thesis, Texas A&M University. Accessed March 04, 2021. http://hdl.handle.net/1969.1/ETD-TAMU-2011-12-10396.

MLA Handbook (7^th Edition):

Bellido Sosa, Edson. “Computational Study of the Development of Graphene Based Devices.” 2012. Web. 04 Mar 2021.

Vancouver:

Bellido Sosa E. Computational Study of the Development of Graphene Based Devices. [Internet] [Masters thesis]. Texas A&M University; 2012. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2011-12-10396.

Council of Science Editors:

Bellido Sosa E. Computational Study of the Development of Graphene Based Devices. [Masters Thesis]. Texas A&M University; 2012. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2011-12-10396

27. Chang, Chin-Yuan. Kinetics of an Inverse Temperature Transition Process and Its Application on Supported Lipid Bilayer.

Degree: PhD, Chemistry, 2011, Texas A&M University

URL: http://hdl.handle.net/1969.1/ETD-TAMU-2010-08-8358

► This dissertation focuses on the study of inverse temperature transition processes of the poly(N-isopropylacrylamide) (PNIPAM) and the elastin-like polypeptides (ELPs). A novel temperature jump microfluidic… (more)

▼ This dissertation focuses on the study of inverse temperature transition processes of the poly(N-isopropylacrylamide) (PNIPAM) and the elastin-like polypeptides (ELPs). A novel temperature jump microfluidic system is introduced and this system shows the ability to measure the kinetics of the PNIPAM and the ELPs collapse without a heat transfer problem. The conformational change of the ELPs during the phase transition process is utilized as a nanoscale protein filter to modulate ligandreceptor binding events on supported lipid bilayers (SLBs). This research study is divided into three main parts. The first part is the development of the temperature jump microfluidics. The kinetics of PNIPAM collapse is used as a model system to show the capability of this new device to measure millisecond time scale phase transition processes. The effects of salts on the kinetics of PNIPAM collapse are also shown in this part. To our knowledge, this is the first study which shows the effects of salts on PNIPAM collapse kinetics. The second part of this research is the application of the novel temperature jump microfluidics. The hydrophobic collapse of ELPs composed of identical sequence but different chain length is investigated. By controlling the molecular weight of the ELPs, the thermodynamic contributions from intermolecular hydrophobic interactions, and intramolecular hydrophobic interactions could be calculated individually for this unique system. The third part is the application of the phase transition property of ELPs. The ELPs are conjugated on the surface of the SLBs as a nanoscale protein filter. The conformation of the ELPs can be modulated by ionic strength of the buffer solution or ambient temperature. The ELPs conjugated SLBs platform showed the ability to block IgG binding to biotin conjugated on the SLBs when the ELPs were in the extended coil state and open the access for protein to bind to biotin in compact globule conformation. Advisors/Committee Members: Cremer, Paul S. (advisor), Batteas, James D. (committee member), Scholtz, J. Martin (committee member), Schweikert, Emile (committee member).

Subjects/Keywords: supported lipid bilayers; ELP; PNIPAM; microfluidics; polymer collapse

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APA (6^th Edition):

Chang, C. (2011). Kinetics of an Inverse Temperature Transition Process and Its Application on Supported Lipid Bilayer. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2010-08-8358

Chicago Manual of Style (16^th Edition):

Chang, Chin-Yuan. “Kinetics of an Inverse Temperature Transition Process and Its Application on Supported Lipid Bilayer.” 2011. Doctoral Dissertation, Texas A&M University. Accessed March 04, 2021. http://hdl.handle.net/1969.1/ETD-TAMU-2010-08-8358.

MLA Handbook (7^th Edition):

Chang, Chin-Yuan. “Kinetics of an Inverse Temperature Transition Process and Its Application on Supported Lipid Bilayer.” 2011. Web. 04 Mar 2021.

Vancouver:

Chang C. Kinetics of an Inverse Temperature Transition Process and Its Application on Supported Lipid Bilayer. [Internet] [Doctoral dissertation]. Texas A&M University; 2011. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2010-08-8358.

Council of Science Editors:

Chang C. Kinetics of an Inverse Temperature Transition Process and Its Application on Supported Lipid Bilayer. [Doctoral Dissertation]. Texas A&M University; 2011. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2010-08-8358

28. Chen, Jixin. Nanofabrication, Plasmon Enhanced Fluorescence and Photo-oxidation Kinetics of CdSe Nanoparticles.

Degree: PhD, Chemistry, 2011, Texas A&M University

URL: http://hdl.handle.net/1969.1/ETD-TAMU-2010-05-7771

► Unconventional nanofabrication techniques; both those which have been newly developed and those under development, had brought inexpensive, facile, yet high quality means to fabricate nanostructures… (more)

▼ Unconventional nanofabrication techniques; both those which have been newly developed and those under development, had brought inexpensive, facile, yet high quality means to fabricate nanostructures that have feature sizes of less than 100 nm in industry and academia. This dissertation focuses on developing unconventional fabrication techniques, building studying platforms, and studying the mechanisms behind them. The studies are divided into two main facets and four chapters. The first facet, in Chapter II and Chapter III, deals with the research and development of different nanofabrication techniques and nanostructures. These techniques include litho-synthesis, colloidal lithography, and photolithography. The nanostructures that were fabricated by these techniques include the metal nanoparticle arrays, and the self-assembled CdSe nanoring arrays. At the same time, the dissertation provides mechanisms and models to describe the physical and chemical nature of these techniques. The second area of this study, in Chapter III to Chapter V, presents the applications of these nanostructures in fundamental studies, i.e. the mechanisms of plasmon enhanced fluorescence and photo-oxidation kinetics of CdSe quantum dots, and applications such as molecular sensing and material fabrication. More specifically, these applications include tuning the optical properties of CdSe quantum dots, biomodification of CdSe quantum dots, and copper ion detection using plasmon and photo enhanced CdSe quantum dots. We have successfully accomplished our research goals in this dissertation. Firstly, we were able to tune the emission wavelength of quantum dots, blue-shifted for up to 45 nm, and their surface functionalization with photo-oxidation. A kinetic model to calculate the photo-oxidation rates was established. Secondly, we established a simple mathematical model to explain the mechanism of plasmon enhanced fluoresce of quantum dots. Our calculation and experimental data support the fluorescence resonance energy transfer (FRET) mechanism between quantum dots and the metal nanoparticles. Thirdly, we successfully pattered the CdSe quantum dots (diameter ~4 nm) into nanorings with tunable diameters and annular sizes on different substrates. We also established a physical model to quantitatively explain the mechanism with the forces that involved in the formation of the nanorings. Advisors/Committee Members: Batteas, James D. (advisor), Cremer, Paul S. (advisor), Goodman, D. W. (committee member), Cheng, Zhengdong (committee member).

Subjects/Keywords: colloidal CdSe quantum dots/nanoparticles/nanocrystals; photo-oxidation/photocorrosion; kinetics; thiol capping ligands; photo-brightening/darkening/blueing; bio-conjugation/functionalization; Nanoring; plasmon enhanced fluorescence; lithography

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APA (6^th Edition):

Chen, J. (2011). Nanofabrication, Plasmon Enhanced Fluorescence and Photo-oxidation Kinetics of CdSe Nanoparticles. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2010-05-7771

Chicago Manual of Style (16^th Edition):

Chen, Jixin. “Nanofabrication, Plasmon Enhanced Fluorescence and Photo-oxidation Kinetics of CdSe Nanoparticles.” 2011. Doctoral Dissertation, Texas A&M University. Accessed March 04, 2021. http://hdl.handle.net/1969.1/ETD-TAMU-2010-05-7771.

MLA Handbook (7^th Edition):

Chen, Jixin. “Nanofabrication, Plasmon Enhanced Fluorescence and Photo-oxidation Kinetics of CdSe Nanoparticles.” 2011. Web. 04 Mar 2021.

Vancouver:

Chen J. Nanofabrication, Plasmon Enhanced Fluorescence and Photo-oxidation Kinetics of CdSe Nanoparticles. [Internet] [Doctoral dissertation]. Texas A&M University; 2011. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2010-05-7771.

Council of Science Editors:

Chen J. Nanofabrication, Plasmon Enhanced Fluorescence and Photo-oxidation Kinetics of CdSe Nanoparticles. [Doctoral Dissertation]. Texas A&M University; 2011. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2010-05-7771

29. Chan, Yang-Hsiang. Applications of Self-assembly for Molecular Electronics, Plasmon Coupling, and Ion Sensing.

Degree: PhD, Chemistry, 2011, Texas A&M University

URL: http://hdl.handle.net/1969.1/ETD-TAMU-2010-05-7805

► This dissertation focused on the applications of self-assembled monolayers (SAMs) technique for the investigation of molecule based electronics, plasmon coupling between CdSe quantum dots and… (more)

▼ This dissertation focused on the applications of self-assembled monolayers (SAMs) technique for the investigation of molecule based electronics, plasmon coupling between CdSe quantum dots and metal nanoparticles (MNPs), and copper ion detection using enhanced emission of CdSe quantum dots (QDs). The SAMs technique provides an approach to establish a robust, two-dimensional and densely packed structure which can be formed on metal or semiconductor surfaces. This allows for the design of molecular assemblies that can be used to understand the details of molecular conduction by employing various electrical testbeds. In this work, the strategy of molecular assemblies was used to pattern metal nanoparticles on GaAs surfaces, thereby furnishing a platform to explore the interactions between QDs and MNPs. The enhanced emission of CdSe QDs by MNPs was then used as a probe for ultrasensitive, cheap, and rapid copper(II) detection. The study is divided into three main facets. The first one aimed at controlling electron transport behavior through porphyrins on surfaces with an eye toward optoelectronic and light harvesting applications. The binding of the porphyrin molecules to Au surfaces, pre-covered with a dodecanethiol matrix, was characterized by FTIR, XPS, AFM, STM, of. This study has shown that the perfluoro coupling group between the porphyrin macrocycle and the thiol tether may provide a means of controlling the tunneling behavior. The second area of this study focused on the design of a simple platform to examine the coupling between metal nanostructures and quantum dot assemblies. Here we demonstrate that by using a patterned array of Au or Ag nanoparticles on GaAs, plasmon enhanced photoluminescence (PL) can be directly measured and quantified by direct scaling of regions with and without metal nanostructures. The third field presented a simple manner for using the enhanced PL of CdSe QDs as a probe for ultrasensitive Cu2+ ion detection and quantitative analysis. The PL of QDs was enhanced by two processes: first, photobrightening of the material, and second, plasmonic enhancement by coupling with Ag nanoprisms. This strong PL leads to a high sensitivity of the QDs over a wide dynamic range for Cu2+ detection, as Cu2+ efficiently quenches the QD emission. Advisors/Committee Members: Batteas, James D. (advisor), Schweikert, Emile A. (committee member), Liang, Hong (committee member), Goodman, Wayne D. (committee member).

Subjects/Keywords: CdSe QDs; plasmon coupling; Cu2+ ion sensor; porphyrin SAMs

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APA (6^th Edition):

Chan, Y. (2011). Applications of Self-assembly for Molecular Electronics, Plasmon Coupling, and Ion Sensing. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2010-05-7805

Chicago Manual of Style (16^th Edition):

Chan, Yang-Hsiang. “Applications of Self-assembly for Molecular Electronics, Plasmon Coupling, and Ion Sensing.” 2011. Doctoral Dissertation, Texas A&M University. Accessed March 04, 2021. http://hdl.handle.net/1969.1/ETD-TAMU-2010-05-7805.

MLA Handbook (7^th Edition):

Chan, Yang-Hsiang. “Applications of Self-assembly for Molecular Electronics, Plasmon Coupling, and Ion Sensing.” 2011. Web. 04 Mar 2021.

Vancouver:

Chan Y. Applications of Self-assembly for Molecular Electronics, Plasmon Coupling, and Ion Sensing. [Internet] [Doctoral dissertation]. Texas A&M University; 2011. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2010-05-7805.

Council of Science Editors:

Chan Y. Applications of Self-assembly for Molecular Electronics, Plasmon Coupling, and Ion Sensing. [Doctoral Dissertation]. Texas A&M University; 2011. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2010-05-7805

30. Fu, Hui. Stimuli-responsive Polymers in Solution and on Grafted Surfaces.

Degree: PhD, Chemistry, 2011, Texas A&M University

URL: http://hdl.handle.net/1969.1/ETD-TAMU-2010-05-7792

► Thermoresponsive polymers such as poly(N-isopropylacrylamide) (PNIPAM) have lower critical solution temperature (LCST) in aqueous solutions. Below the LCST, these polymers are hydrophilic with an extended… (more)

▼ Thermoresponsive polymers such as poly(N-isopropylacrylamide) (PNIPAM) have lower critical solution temperature (LCST) in aqueous solutions. Below the LCST, these polymers are hydrophilic with an extended coil conformation. Above the LCST, they undergo a sharp phase transition to form a collapsed hydrophobic conformation. The LCSTs are also affected by cosolutes and the effects of anions on LCSTs follow the Hofmeister series. We successfully used a simple digital melting point apparatus to study the effects of heating rates, solvent compositions, cosolutes, and redox state, on the LCSTs of thermoresponsive polymers. Moreover, the temperature range of the apparatus allowed for analyses at much higher temperatures and provides a simple way to examine irregular clouding behavior in more complex systems. Meanwhile, stimuli-responsive surfaces grafted with thermoresponsive polymers can switch from hydrophilic to hydrophobic thermally. As the LCST can be subsequently changed with the addition of salts, the salt effects on the wettability of these thermoresponsive surfaces will dramatically impact the surface performance. In this dissertation, I prepared PNIPAM/SiO2 nanocomposite surfaces by a covalent layer-by- layer assembly procedure and such surfaces were then used in studies of salts effects on surface wettability. Both the effects of anions and cations on the changes of advancing angles (Delta Theta a) of the PNIPAM/SiO2 nanocomposite surfaces were significant (Delta Theta a up to 90 degrees). The anion effects on the surface wettability followed the Hofmeister effect as expected. Parallel studies on solution showed that variation of cations had a large effect on the LCST of PNIPAM too. Moreover, analyses of the Theta a and LCST data using activity instead of using concentration showed different orders for the cation effects which were readily grouped by the cation charge numbers. No difference was seen for the anion effects in similar studies. AFM studies showed that surface morphology changes were correlated with the Delta Theta a. Advisors/Committee Members: Bergbreiter, David E. (advisor), Singleton, Daniel A. (committee member), Batteas, James D. (committee member), Grunlan, Melissa A. (committee member).

Subjects/Keywords: Stimuli-responsive; Lower critical solution temperature; nanocomposite surface; cation effect; anion effect

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APA (6^th Edition):

Fu, H. (2011). Stimuli-responsive Polymers in Solution and on Grafted Surfaces. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2010-05-7792

Chicago Manual of Style (16^th Edition):

Fu, Hui. “Stimuli-responsive Polymers in Solution and on Grafted Surfaces.” 2011. Doctoral Dissertation, Texas A&M University. Accessed March 04, 2021. http://hdl.handle.net/1969.1/ETD-TAMU-2010-05-7792.

MLA Handbook (7^th Edition):

Fu, Hui. “Stimuli-responsive Polymers in Solution and on Grafted Surfaces.” 2011. Web. 04 Mar 2021.

Vancouver:

Fu H. Stimuli-responsive Polymers in Solution and on Grafted Surfaces. [Internet] [Doctoral dissertation]. Texas A&M University; 2011. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2010-05-7792.

Council of Science Editors:

Fu H. Stimuli-responsive Polymers in Solution and on Grafted Surfaces. [Doctoral Dissertation]. Texas A&M University; 2011. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2010-05-7792

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