You searched for +publisher:"Vanderbilt University" +contributor:("Timothy Hanusa").
Showing records 1 – 14 of
14 total matches.
No search limiters apply to these results.
Vanderbilt University
1.
Rigueur, John Lucien.
Multiwalled carbon nanotube films: fabrication techniques and applications.
Degree: PhD, Physics, 2012, Vanderbilt University
URL: http://hdl.handle.net/1803/12114 
► The first part of the dissertation focuses on randomly oriented freestanding films of multi-walled carbon nanotubes (MWCNTs), also known as buckypapers, which have been fabricated…
(more)
▼ The first part of the dissertation focuses on randomly oriented freestanding films of multi-walled carbon nanotubes (MWCNTs), also known as buckypapers, which have been fabricated by a two-step process using electrophoretic deposition (EPD). These multi-walled carbon nanotubes films were cast onto stainless steel electrodes from aqueous suspensions by EPD. Using a facile mechanical cleavage technique, the films were liberated from their underlying electrodes to yield the buckypapers. We investigated the films’ thickness, morphology, and surface topology using, respectively, profilometry, scanning electron microscopy, and atomic force microscopy. Mechanical characterization of the buckypapers revealed the average tensile strength and Young’s modulus to be 14.5 MPa and 3.3 GPa, respectively.
The second part of this dissertation focuses on vertically aligned multi-walled carbon nanotubes. The purpose of our investigation was to optimize the growth of catalyst assisted chemical vapor deposition (CVD) grown carbon nanotubes for use as a photon absorbers in mid- to far-infrared applications. Improvement of the height and density of the carbon nanotubes will effectively increase the films absorptivity, bringing this material closer to an ideal absorber. NASA is currently exploring the use of this technology towards improving the stray light suppression of space flight instruments for future earth and space science missions. Detrimental to these scientific instruments is the stray light that scatters on interior telescope and instrument surfaces, thereby reducing the performance of observational instruments. In order to control this undesired effect, low-reflectance surface treatments are implemented in structural instrument designs. Z306 black paint is traditionally used to absorb stray photons, but advanced absorbers that employ films of multi-walled carbon nanotubes have been shown to provide an order of magnitude improvement over current surface treatments in the UV-visible-near infrared wavelengths. To this end, we varied the thickness of the iron catalyst layer and deposition conditions; varied hydrogen exposure times of substrates to optimize the MWCNT length and film density for efficient absorption of longer wavelength photons. Scanning electron microscopy is used to characterize film density and MWCNT height, and hemispherical reflectance measurements are used to quantify performance of the absorptive films.
Advisors/Committee Members: Timothy Hanusa (Committee Chair).
Subjects/Keywords: blackbody; electrophoretic deposition; chemical vapor deposition; nanotubes
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Rigueur, J. L. (2012). Multiwalled carbon nanotube films: fabrication techniques and applications. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/12114
Chicago Manual of Style (16th Edition):
Rigueur, John Lucien. “Multiwalled carbon nanotube films: fabrication techniques and applications.” 2012. Doctoral Dissertation, Vanderbilt University. Accessed April 11, 2021.
http://hdl.handle.net/1803/12114.
MLA Handbook (7th Edition):
Rigueur, John Lucien. “Multiwalled carbon nanotube films: fabrication techniques and applications.” 2012. Web. 11 Apr 2021.
Vancouver:
Rigueur JL. Multiwalled carbon nanotube films: fabrication techniques and applications. [Internet] [Doctoral dissertation]. Vanderbilt University; 2012. [cited 2021 Apr 11].
Available from: http://hdl.handle.net/1803/12114.
Council of Science Editors:
Rigueur JL. Multiwalled carbon nanotube films: fabrication techniques and applications. [Doctoral Dissertation]. Vanderbilt University; 2012. Available from: http://hdl.handle.net/1803/12114
Vanderbilt University
2.
Meier, Ryan M.
Manganese(II) Indenyl Compounds: Synthesis, Characterization, and Reactivities with Oxygen Donor Ligands.
Degree: PhD, Chemistry, 2012, Vanderbilt University
URL: http://hdl.handle.net/1803/12803
► A series of bis(indenyl)manganese(II) complexes have been synthesized with methyl substituents. These species appear to be high spin with no-evidence of spin-crossover. However, the physical…
(more)
▼ A series of bis(indenyl)manganese(II) complexes have been synthesized with methyl substituents. These species appear to be high spin with no-evidence of spin-crossover. However, the physical structures of these compounds are unique in comparison other bis(indenyl) complexes of first row transition metal complexes. The bis(indenyl)manganese compounds display a very flexible Mn-indenyl interaction that results in oligomerization and polymerization of the compounds unless sufficient steric bulk can be provided.
Dimeric (indenyl)manganese halides can be synthesized by salt metathesis reactions of the appropriate stoichiometries. A few of these compounds react with elemental oxygen at low temperature (-78 °C) and very low oxygen concentrations (< 5ppm). Spectroscopic data suggests the formation of a manganese(III) superoxide complex.
A new synthetic route for the preparation of manganese(II) aryloxide compounds has been developed. Of interesting note is the observation that manganese(II) preferentially coordinates an aryloxide ligand over an indenyl ligand; however, these compounds appear to require sterically bulky phenoxide ligands in order to prevent polymerization and to help solubility.
Advisors/Committee Members: David Wright (committee member), Charles Lukehart (committee member), James Wittig (committee member), Timothy Hanusa (Committee Chair).
Subjects/Keywords: chemistry; organometallic; inorganic
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Meier, R. M. (2012). Manganese(II) Indenyl Compounds: Synthesis, Characterization, and Reactivities with Oxygen Donor Ligands. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/12803
Chicago Manual of Style (16th Edition):
Meier, Ryan M. “Manganese(II) Indenyl Compounds: Synthesis, Characterization, and Reactivities with Oxygen Donor Ligands.” 2012. Doctoral Dissertation, Vanderbilt University. Accessed April 11, 2021.
http://hdl.handle.net/1803/12803.
MLA Handbook (7th Edition):
Meier, Ryan M. “Manganese(II) Indenyl Compounds: Synthesis, Characterization, and Reactivities with Oxygen Donor Ligands.” 2012. Web. 11 Apr 2021.
Vancouver:
Meier RM. Manganese(II) Indenyl Compounds: Synthesis, Characterization, and Reactivities with Oxygen Donor Ligands. [Internet] [Doctoral dissertation]. Vanderbilt University; 2012. [cited 2021 Apr 11].
Available from: http://hdl.handle.net/1803/12803.
Council of Science Editors:
Meier RM. Manganese(II) Indenyl Compounds: Synthesis, Characterization, and Reactivities with Oxygen Donor Ligands. [Doctoral Dissertation]. Vanderbilt University; 2012. Available from: http://hdl.handle.net/1803/12803
Vanderbilt University
3.
Pecyna, Jacek Grzegorz.
Polar and ionic liquid crystals based on the [closo-1-CB9H10]– and [closo-1-CB11H12]– boron clusters.
Degree: PhD, Chemistry, 2015, Vanderbilt University
URL: http://hdl.handle.net/1803/11004
► The subject of this dissertation is the development and evaluation of polar and ionic liquid crystals derived from boron clusters for electrooptical and anisometric ion…
(more)
▼ The subject of this dissertation is the development and evaluation of polar and ionic liquid crystals derived from boron clusters for electrooptical and anisometric ion transport applications.
Liquid crystal is a state of matter characterized by properties intermediate between that of an ordinary liquid (fluidity, molecular disorder) and crystalline solid (long-range orientational and positional order) and is formed by anisometric rod-like, disc-like or bent-core molecules. The choice of the structural elements of the rigid core and flexible tails dictates the type of mesophase and its properties. Polyhedral boron clusters, possessing unusual molecular and electronic properties not offered by other organic molecules, are suitable core element for liquid crystalline materials for advanced applications. Thus, zwitterionic polar materials are derived from [closo-1-CB9H10]– and [closo-1-CB11H12]– anions by substitution with an onium fragment (pyridinium or sulfonium) and one electrically neutral fragment at antipodal positions. The ionic liquid crystals are designed as an ion pair, in which the anisometric anion is the major driver for induction of liquid crystalline properties.
Within this context, practical and efficient synthetic methodologies were developed for functionalization and functional group transformations for anions [closo-1-CB11H12]– and [closo-1-CB9H10]– and a number of new zwitterionic and ionic materials for electroptical and anisometric ion transport applications have been prepared. The resulting zwitterionic and ionic materials were investigated in neat form and as additives to nematic hosts. Thermal, optical, dielectric, and powder X-ray methods were employed to characterize the new materials. They were found to be compatible with the nematic hosts, and they increased the dielectric response of the hosts due to high extrapolated dielectric anisotropy in a range of 18-70. Sulfonium-substituted zwitterions exhibit exclusively a nematic behavior, while pyridinium derivatives form either nematic or smectic phases. Ionic materials were found to have properties characteristic for ionic liquid crystals. Both polar and ionic materials were found to have properties promising for the desired applications.
Advisors/Committee Members: Jeffrey Johnston (committee member), Timothy Hanusa (committee member), Kane Jennings (committee member), Piotr Kaszynski (Committee Chair).
Subjects/Keywords: organic chemistry; boron clusters; liquid crystals; materials science
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Pecyna, J. G. (2015). Polar and ionic liquid crystals based on the [closo-1-CB9H10]– and [closo-1-CB11H12]– boron clusters. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/11004
Chicago Manual of Style (16th Edition):
Pecyna, Jacek Grzegorz. “Polar and ionic liquid crystals based on the [closo-1-CB9H10]– and [closo-1-CB11H12]– boron clusters.” 2015. Doctoral Dissertation, Vanderbilt University. Accessed April 11, 2021.
http://hdl.handle.net/1803/11004.
MLA Handbook (7th Edition):
Pecyna, Jacek Grzegorz. “Polar and ionic liquid crystals based on the [closo-1-CB9H10]– and [closo-1-CB11H12]– boron clusters.” 2015. Web. 11 Apr 2021.
Vancouver:
Pecyna JG. Polar and ionic liquid crystals based on the [closo-1-CB9H10]– and [closo-1-CB11H12]– boron clusters. [Internet] [Doctoral dissertation]. Vanderbilt University; 2015. [cited 2021 Apr 11].
Available from: http://hdl.handle.net/1803/11004.
Council of Science Editors:
Pecyna JG. Polar and ionic liquid crystals based on the [closo-1-CB9H10]– and [closo-1-CB11H12]– boron clusters. [Doctoral Dissertation]. Vanderbilt University; 2015. Available from: http://hdl.handle.net/1803/11004
Vanderbilt University
4.
Gulka, Christopher Peter.
Gold as a Sensing Platform for the Rapid Detection of Explosives and Malarial Biomarkers.
Degree: PhD, Chemistry, 2014, Vanderbilt University
URL: http://hdl.handle.net/1803/14626
► Gold’s resistance to oxidation and exhibition of unique chemical and physical properties enable the development of current sensor and diagnostic platforms. This dissertation elucidates novel…
(more)
▼ Gold’s resistance to oxidation and exhibition of unique chemical and physical properties enable the development of current sensor and diagnostic platforms. This dissertation elucidates novel sensor platforms for the rapid detection of explosives and malarial biomarkers, respectively, by exploiting the catalytic and chromogenic properties of nanoscale gold. Initially, bulk gold serves as a substrate to biomimetically recognize explosive small molecules with peptide ligands at the cost of sensitivity. To enhance detection, immobilized gold nanoparticles electrocatalytically facilitate explosive molecule detection in a size-dependent manner. Taking advantage of gold’s optical properties, a colorimetric proof-of-concept assay amenable to the developing world is presented by capturing a malarial protein biomarker, inducing a red-to-purple color change and overcoming many obstacles associated with low-resource diagnostics. To increase biomarker sensitivity, gold-plated polystyrene microspheres mimic the phenomenon elicited by coffee rings to capture and concentrate the protein, allowing for the rapid interpretation of results and providing a simple user interface.
Advisors/Committee Members: Richard Haglund (committee member), Timothy Hanusa (committee member), Darryl Bornhop (committee member), David Wright (Committee Chair).
Subjects/Keywords: coffee ring; malaria; HRP-II; TNT; gold nanoparticles
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Gulka, C. P. (2014). Gold as a Sensing Platform for the Rapid Detection of Explosives and Malarial Biomarkers. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/14626
Chicago Manual of Style (16th Edition):
Gulka, Christopher Peter. “Gold as a Sensing Platform for the Rapid Detection of Explosives and Malarial Biomarkers.” 2014. Doctoral Dissertation, Vanderbilt University. Accessed April 11, 2021.
http://hdl.handle.net/1803/14626.
MLA Handbook (7th Edition):
Gulka, Christopher Peter. “Gold as a Sensing Platform for the Rapid Detection of Explosives and Malarial Biomarkers.” 2014. Web. 11 Apr 2021.
Vancouver:
Gulka CP. Gold as a Sensing Platform for the Rapid Detection of Explosives and Malarial Biomarkers. [Internet] [Doctoral dissertation]. Vanderbilt University; 2014. [cited 2021 Apr 11].
Available from: http://hdl.handle.net/1803/14626.
Council of Science Editors:
Gulka CP. Gold as a Sensing Platform for the Rapid Detection of Explosives and Malarial Biomarkers. [Doctoral Dissertation]. Vanderbilt University; 2014. Available from: http://hdl.handle.net/1803/14626
Vanderbilt University
5.
Ringstrand, Bryan Scott.
Boron Clusters as the Centerpiece of Advanced Liquid Crystals: Fundamental Chemistry and Properties.
Degree: PhD, Chemistry, 2011, Vanderbilt University
URL: http://hdl.handle.net/1803/11205
► Liquid crystals incorporating boron clusters are of interest for electro-optics, ion transport, and fundamental structure-property relationship studies. A liquid crystal is a fluid possessing orientational…
(more)
▼ Liquid crystals incorporating boron clusters are of interest for electro-optics, ion transport,
and fundamental structure-property relationship studies. A liquid crystal is a fluid possessing orientational and positional order between that of the lattice of a solid (long-range orientational and long-range positional order) and the random disorder (no orientational or positional order) of a liquid. Balance between the rigidity of the molecular core and flexible periphery dictates the type of liquid crystalline phase and its stability. Anisometric molecules, typically rods or discs, form liquid crystalline phases. closo-Boron clusters are inorganic structures characterized by highly delocalized bonding and high chemical, oxidative, and thermal stability. These clusters can exist as highly
symmetrical molecules that are either neutral or negatively charged.
Within this framework, a negatively charged boron cluster, [closo-1-CB9H10]-, was exploited as the centerpiece of both zwitterionic and ionic liquid crystalline materials. Access to these materials was limited by the lack of synthetic methodology and understanding of reactive intermediates of the [closo-1-CB9H10]- anion. Therefore, a systematic approach was taken to advance the synthetic and physical-organic chemistry of the [closo-1-CB9H10]- anion within the context of incorporating it into liquid crystalline structures. Once this stepwise approach was completed, the newly discovered methodology was employed in the preparation of advanced liquid crystalline materials containing the [closo-1-CB9H10]- anion.
Both the zwitterionic and ionic materials were studied for liquid crystalline
properties using thermal, optical, and in some cases dielectric and XRD methods. The zwitterionic materials posses large longitudinal dipole moments and were utilized as additives to other liquid crystals, which caused large increases in the dielectric properties
of the bulk material. These findings are promising for electro-optical applications. The
ionic materials displayed typical liquid crystalline behavior expected for ionic
architectures. However, the design of such materials is unique in that the anisometric
anion is the driving force behind the organization of the molecules in the fluid phase.
These types of materials are promising for photo-physical effects and the potential transport of ions for energy storage or delivery.
Advisors/Committee Members: Timothy Hanusa (committee member), Kane Jennings (committee member), Jeffrey Johnston (committee member), Piotr Kaszynski (Committee Chair).
Subjects/Keywords: organic chemistry; materials science; liquid crystals; boron clusters
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Ringstrand, B. S. (2011). Boron Clusters as the Centerpiece of Advanced Liquid Crystals: Fundamental Chemistry and Properties. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/11205
Chicago Manual of Style (16th Edition):
Ringstrand, Bryan Scott. “Boron Clusters as the Centerpiece of Advanced Liquid Crystals: Fundamental Chemistry and Properties.” 2011. Doctoral Dissertation, Vanderbilt University. Accessed April 11, 2021.
http://hdl.handle.net/1803/11205.
MLA Handbook (7th Edition):
Ringstrand, Bryan Scott. “Boron Clusters as the Centerpiece of Advanced Liquid Crystals: Fundamental Chemistry and Properties.” 2011. Web. 11 Apr 2021.
Vancouver:
Ringstrand BS. Boron Clusters as the Centerpiece of Advanced Liquid Crystals: Fundamental Chemistry and Properties. [Internet] [Doctoral dissertation]. Vanderbilt University; 2011. [cited 2021 Apr 11].
Available from: http://hdl.handle.net/1803/11205.
Council of Science Editors:
Ringstrand BS. Boron Clusters as the Centerpiece of Advanced Liquid Crystals: Fundamental Chemistry and Properties. [Doctoral Dissertation]. Vanderbilt University; 2011. Available from: http://hdl.handle.net/1803/11205
Vanderbilt University
6.
Jackson, Enrique Monte.
Development and Thermal Properties of Carbon Nanotube-Polymer Composites.
Degree: PhD, Interdisciplinary Materials Science, 2014, Vanderbilt University
URL: http://hdl.handle.net/1803/14782
► The favorable conductive properties of carbon nanotubes (CNTs) offer opportunities for constructing CNT-based nanocomposites with improved thermal conduction for a range of potential applications. Such…
(more)
▼ The favorable conductive properties of carbon nanotubes (CNTs) offer opportunities for constructing CNT-based nanocomposites with improved thermal conduction for a range of potential applications. Such lightweight composite materials are expected to have thermal properties that depend on their CNT volume fraction and operating temperature. The construction of CNT-based nanocomposites is challenged by the available processing methods for CNTs that are compatible with the construction of multi-laminated composite structures.
The overall goal of this effort is to develop enhanced thermal properties in carbon nanotube-polymer composites that can replace traditional aerospace metallic materials to reduce the weight in space structures. The key innovation of this dissertation is in dispersing the carbon nanotubes onto a prepreg composite structure that sustains thermal storage and increase the thermal transport to support scientific instrumentation to more effectively radiate heat from a composite structure while increasing the thermal properties. The employed structures consisted of individual plies of IM7 prepreg composite with an embedded 8552 epoxy that were each coated with a CNT layer and then combined into the final composite structure using a vacuum-based hand layup technique for curing the 8552 epoxy. The composites were investigated by Raman spectroscopy, thermogravimetric analysis, thermal diffusivity, and differential scanning calorimetry.
With varying the concentration of SWCNT up to 30 wt% to the IM7 prepreg composite, its heat capacity sustained over the tested temperature range and its through-thickness thermal diffusivity increased by 30% vs. the virgin composite material. By modeling, such additions of randomly oriented SWCNTs are suggested to increase the in-plane thermal conductivity by 120 to 150% over the temperature range of 120 to 470 K and by 30% in the through-thickness direction. A possible explanation of these improvements in the thermal conductivities are the reductions of the interfacial resistances between the SWCNTs, the 8552 epoxy, and the IM7 composite.
The developed methods provide the opportunity for enhancing the thermal properties of a composite through the use of CNTs as additives. Such improvements would be particularly useful in aerospace applications for solar arrays, fairings, and thermal radiators.
Advisors/Committee Members: Dr. Yaqiong Xu (committee member), Dr. Timothy Hanusa (committee member), Dr. Paul Laibinis (Committee Chair).
Subjects/Keywords: carbon nanotubes; composites; thermal conductivity
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Jackson, E. M. (2014). Development and Thermal Properties of Carbon Nanotube-Polymer Composites. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/14782
Chicago Manual of Style (16th Edition):
Jackson, Enrique Monte. “Development and Thermal Properties of Carbon Nanotube-Polymer Composites.” 2014. Doctoral Dissertation, Vanderbilt University. Accessed April 11, 2021.
http://hdl.handle.net/1803/14782.
MLA Handbook (7th Edition):
Jackson, Enrique Monte. “Development and Thermal Properties of Carbon Nanotube-Polymer Composites.” 2014. Web. 11 Apr 2021.
Vancouver:
Jackson EM. Development and Thermal Properties of Carbon Nanotube-Polymer Composites. [Internet] [Doctoral dissertation]. Vanderbilt University; 2014. [cited 2021 Apr 11].
Available from: http://hdl.handle.net/1803/14782.
Council of Science Editors:
Jackson EM. Development and Thermal Properties of Carbon Nanotube-Polymer Composites. [Doctoral Dissertation]. Vanderbilt University; 2014. Available from: http://hdl.handle.net/1803/14782
Vanderbilt University
7.
Covington, Cody Lance.
Chiroptical Spectroscopic Studies on Surfactants, Other Aggregating Systems, and Natural Products.
Degree: PhD, Chemistry, 2016, Vanderbilt University
URL: http://hdl.handle.net/1803/11624
► Recent experimental studies have shown unexpected chiroptical response from some chiral surfactant molecules. In these cases, the magnitude of the specific optical rotation was seen…
(more)
▼ Recent experimental studies have shown unexpected chiroptical response from some chiral surfactant molecules. In these cases, the magnitude of the specific optical rotation was seen to change as a function of surfactant concentration, which is considered to be due to molecular aggregation and contrary to that known for typical organic molecules. To explain these experimental results on the +10,000 atom surfactant systems, non-traditional methods are necessary. To that end, a large number of molecular dynamics simulations, quantum mechanical calculations, and extensive analysis have been performed on a model system, the lauryl ester of phenylalanine. Monomer-dimer equilibrium, representing the simplest form of aggregation, and its influence on the Horeau effect, have also been investigated using pantolactone and 2-hydroxy-3-pinanone as test cases. Also a novel chiroptical spectral analysis method utilizing the Dissymmetry Factor (DF) spectrum has been developed. Studies ranging from rigid to flexible molecules have demonstrated the advantages of the DF method, especially when several diastereomers are involved. Using the DF spectrum as an additional means of analysis, the previously undetermined absolute configurations of four natural products have been determined.
Advisors/Committee Members: Timothy Hanusa (committee member), Terry Lybrand (committee member), Janet Macdonald (committee member), Kalman Varga (committee member), Prasad Polavarapu (Committee Chair).
Subjects/Keywords: chiroptical spectroscopy
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Covington, C. L. (2016). Chiroptical Spectroscopic Studies on Surfactants, Other Aggregating Systems, and Natural Products. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/11624
Chicago Manual of Style (16th Edition):
Covington, Cody Lance. “Chiroptical Spectroscopic Studies on Surfactants, Other Aggregating Systems, and Natural Products.” 2016. Doctoral Dissertation, Vanderbilt University. Accessed April 11, 2021.
http://hdl.handle.net/1803/11624.
MLA Handbook (7th Edition):
Covington, Cody Lance. “Chiroptical Spectroscopic Studies on Surfactants, Other Aggregating Systems, and Natural Products.” 2016. Web. 11 Apr 2021.
Vancouver:
Covington CL. Chiroptical Spectroscopic Studies on Surfactants, Other Aggregating Systems, and Natural Products. [Internet] [Doctoral dissertation]. Vanderbilt University; 2016. [cited 2021 Apr 11].
Available from: http://hdl.handle.net/1803/11624.
Council of Science Editors:
Covington CL. Chiroptical Spectroscopic Studies on Surfactants, Other Aggregating Systems, and Natural Products. [Doctoral Dissertation]. Vanderbilt University; 2016. Available from: http://hdl.handle.net/1803/11624
Vanderbilt University
8.
He, Weidong.
Ultra-small nanocrystals: synthesis, optical and magnetic properties, oriented attachment, and film assembly.
Degree: PhD, Interdisciplinary Materials Science, 2012, Vanderbilt University
URL: http://hdl.handle.net/1803/15320
► This dissertation focuses on the colloidal synthesis, and size-dependent optical & magnetic properties of several nanocrystals, such as EuX (X=O, S, Se, Te), Eu2O2S, and…
(more)
▼ This dissertation focuses on the colloidal synthesis, and size-dependent optical & magnetic properties of several nanocrystals, such as EuX (X=O, S, Se, Te), Eu2O2S, and Te nanoparticles and nanorods. Significant Néel temperature enhancement and diamagnetic-magnetism transition were observed in EuTe and Eu2O2S nanocrystals, respectively. To better control the synthesis and improve the properties of these materials, the reaction kinetics and growth mechanism of EuS nanocrystals were evaluated using our newly-derived analytical expression for van der Waals interaction between a growing nanorod and an attaching nanoparticle. Towards the application of these nanocrystals, the synthesized nanocrystals were deposited into uniform nano-films using an automatic electrophoretic deposition technique.
Advisors/Committee Members: Timothy Hanusa (committee member), Kalman Varga (committee member), Jason Valentine (committee member), James H. Dickerson (Committee Chair).
Subjects/Keywords: van der Waals interaction; nanoparticles; optical; magnetic; oriented attachment; electrophoretic deposition
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
He, W. (2012). Ultra-small nanocrystals: synthesis, optical and magnetic properties, oriented attachment, and film assembly. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/15320
Chicago Manual of Style (16th Edition):
He, Weidong. “Ultra-small nanocrystals: synthesis, optical and magnetic properties, oriented attachment, and film assembly.” 2012. Doctoral Dissertation, Vanderbilt University. Accessed April 11, 2021.
http://hdl.handle.net/1803/15320.
MLA Handbook (7th Edition):
He, Weidong. “Ultra-small nanocrystals: synthesis, optical and magnetic properties, oriented attachment, and film assembly.” 2012. Web. 11 Apr 2021.
Vancouver:
He W. Ultra-small nanocrystals: synthesis, optical and magnetic properties, oriented attachment, and film assembly. [Internet] [Doctoral dissertation]. Vanderbilt University; 2012. [cited 2021 Apr 11].
Available from: http://hdl.handle.net/1803/15320.
Council of Science Editors:
He W. Ultra-small nanocrystals: synthesis, optical and magnetic properties, oriented attachment, and film assembly. [Doctoral Dissertation]. Vanderbilt University; 2012. Available from: http://hdl.handle.net/1803/15320
Vanderbilt University
9.
Sims, Artez Laurant.
Development and Application of Dendritic Systems for Targeted Intracellular Delivery.
Degree: PhD, Chemistry, 2013, Vanderbilt University
URL: http://hdl.handle.net/1803/12538
► This project reports the synthesis of several dendritic polymers towards applications in intracellular transport. The structures discussed feature variations in core, periphery, and branched units…
(more)
▼ This project reports the synthesis of several dendritic polymers towards applications in intracellular transport. The structures discussed feature variations in core, periphery, and branched units all of which are manipulated to create sophisticated designs of delivery.
One of the dendrimers reported is designed to provide delivery into the cellular cytoplasm. An alternative synthesis for this second generation dendritic transporter is presented and used to attach novel antibodies. In this approach, conjugation of transporter and single-chained antibody is used for viral therapy. Comparatively, the bioconjugate is demonstrated to achieve viral inhibition against cells infected with rotavirus more effectively than antibody alone. The investigation utilizes a novel approach for viral treatment.
To extend the utility of dendrimers a library of third generation dendrimers were also created. As a synthetic advantage, the structures undergo a facile preparation process and demonstrate the potential for creating systems featuring polyvalent peripheries. Using this approach, third generation structures are developed featuring emanating units containing ethyl and hexy alkyl units and guanidine head groups.
Additional application of this synthetic route is used to construct third generation dendrimers for delivery to the mitochondria. The dendrimers are modified with various ratios of lipophilic and cationic functionality at the periphery. Investigation of the construct featuring an equal distribution of perpheritic lipophilic and cationic functional groups demonstrates mitochondria targeting. The findings from these investigations highlight approaches using dendrimers to facilitate cellular delivery for therapeutic application.
Advisors/Committee Members: Timothy Hanusa (committee member), David Wright (committee member), James E. Crowe Jr. (committee member), Eva M. Harth (Committee Chair).
Subjects/Keywords: colocalization; rotavirus treatment; dendrimers
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Sims, A. L. (2013). Development and Application of Dendritic Systems for Targeted Intracellular Delivery. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/12538
Chicago Manual of Style (16th Edition):
Sims, Artez Laurant. “Development and Application of Dendritic Systems for Targeted Intracellular Delivery.” 2013. Doctoral Dissertation, Vanderbilt University. Accessed April 11, 2021.
http://hdl.handle.net/1803/12538.
MLA Handbook (7th Edition):
Sims, Artez Laurant. “Development and Application of Dendritic Systems for Targeted Intracellular Delivery.” 2013. Web. 11 Apr 2021.
Vancouver:
Sims AL. Development and Application of Dendritic Systems for Targeted Intracellular Delivery. [Internet] [Doctoral dissertation]. Vanderbilt University; 2013. [cited 2021 Apr 11].
Available from: http://hdl.handle.net/1803/12538.
Council of Science Editors:
Sims AL. Development and Application of Dendritic Systems for Targeted Intracellular Delivery. [Doctoral Dissertation]. Vanderbilt University; 2013. Available from: http://hdl.handle.net/1803/12538
Vanderbilt University
10.
Gilbert Corder, Stephanie Nicole.
Ultrafast relaxation dynamics and optical properties of GaAs and GaAs-based heterostructures.
Degree: PhD, Interdisciplinary Materials Science, 2014, Vanderbilt University
URL: http://hdl.handle.net/1803/14568
► Three previously unreported photo-carrier relaxation pathways are presented and discussed in GaAs-based systems. In bulk GaAs, a transient bleach of the spin-split exciton transition 1s->2p…
(more)
▼ Three previously unreported photo-carrier relaxation pathways are presented and discussed in GaAs-based systems. In bulk GaAs, a transient bleach of the spin-split exciton transition 1s->2p is reported following photo-excitation at low temperatures and is likely caused by final state blocking of the 2p_1 exciton level. The bleach of the 1s->2p_-1 transition is delayed with respect to that of the free carriers and 1s->2p_+1, suggesting electronic relaxation occurs through two simultaneous mechanisms: elastic scattering between quantized conduction band states and spin-dependent relaxation through the 2p_1 exciton states. For ErAs:GaAs composites, the response at short time delays is completely dependent on the occupation of the interface trap state between the ErAs nanoparticles and the GaAs matrix. Occupation of the interface state depends on the photo-carrier energy, carrier density, and trap density. Carrier scattering from the interface state plays a large role in the response as it prevents full relaxation of the system on ultrashort timescales. The composite ErAs:GaAs systems also exhibit an oscillatory response highly suggestive of surface plasmon polaritons at the interface between the semi-metallic ErAs and semiconducting GaAs, which couple to the GaAs phonon modes. The oscillation frequencies are observed to follow the same trend with volume fraction as the static absorption resonance peaks, suggesting different nanoparticle size distributions exist with different ErAs incorporation.
Advisors/Committee Members: Jimmy Davidson (committee member), Kalman Varga (committee member), Richard Haglund (committee member), Timothy Hanusa (committee member), Norman Tolk (Committee Chair).
Subjects/Keywords: Ultrafast dynamics; gallium arsenide; carrier relaxation; spectroscopy; semiconductors; photonics; optics
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Gilbert Corder, S. N. (2014). Ultrafast relaxation dynamics and optical properties of GaAs and GaAs-based heterostructures. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/14568
Chicago Manual of Style (16th Edition):
Gilbert Corder, Stephanie Nicole. “Ultrafast relaxation dynamics and optical properties of GaAs and GaAs-based heterostructures.” 2014. Doctoral Dissertation, Vanderbilt University. Accessed April 11, 2021.
http://hdl.handle.net/1803/14568.
MLA Handbook (7th Edition):
Gilbert Corder, Stephanie Nicole. “Ultrafast relaxation dynamics and optical properties of GaAs and GaAs-based heterostructures.” 2014. Web. 11 Apr 2021.
Vancouver:
Gilbert Corder SN. Ultrafast relaxation dynamics and optical properties of GaAs and GaAs-based heterostructures. [Internet] [Doctoral dissertation]. Vanderbilt University; 2014. [cited 2021 Apr 11].
Available from: http://hdl.handle.net/1803/14568.
Council of Science Editors:
Gilbert Corder SN. Ultrafast relaxation dynamics and optical properties of GaAs and GaAs-based heterostructures. [Doctoral Dissertation]. Vanderbilt University; 2014. Available from: http://hdl.handle.net/1803/14568
Vanderbilt University
11.
Marvel, Robert Edward.
Physics and Processing of Vanadium Dioxide for Optical Devices.
Degree: PhD, Interdisciplinary Materials Science, 2016, Vanderbilt University
URL: http://hdl.handle.net/1803/10429
► This dissertation examines the fundamental physical properties and material processing methods required to design and fabricate the next generation of optical modulators based on the…
(more)
▼ This dissertation examines the fundamental physical properties and material processing methods required to design and fabricate the next generation of optical modulators based on the vanadium dioxide metal-insulator transition. All-optical devices capable of performing at GHz speeds, which are only limited by the laser pulse duration, were designed, fabricated and tested. Broad-band pump-probe experiments examined the femtosecond phase transition dynamics in vanadium dioxide when excited at a range of wavelengths from 400 nm to 1500 nm and indicate that THz modulation speeds could be achieved. In addition, fabrication methods and doping were explored as paths to tune the phase transition properties. The optical modulator design and material performance are discussed in the context of current state-of-the-art technology.
Advisors/Committee Members: Timothy Hanusa (committee member), Norman Tolk (committee member), Bridget Rogers (committee member), Richard Haglund (Committee Chair), Jason Valentine (Committee Chair).
Subjects/Keywords: laser spectroscopy; optical devices; vanadium dioxide; optical properties
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Marvel, R. E. (2016). Physics and Processing of Vanadium Dioxide for Optical Devices. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/10429
Chicago Manual of Style (16th Edition):
Marvel, Robert Edward. “Physics and Processing of Vanadium Dioxide for Optical Devices.” 2016. Doctoral Dissertation, Vanderbilt University. Accessed April 11, 2021.
http://hdl.handle.net/1803/10429.
MLA Handbook (7th Edition):
Marvel, Robert Edward. “Physics and Processing of Vanadium Dioxide for Optical Devices.” 2016. Web. 11 Apr 2021.
Vancouver:
Marvel RE. Physics and Processing of Vanadium Dioxide for Optical Devices. [Internet] [Doctoral dissertation]. Vanderbilt University; 2016. [cited 2021 Apr 11].
Available from: http://hdl.handle.net/1803/10429.
Council of Science Editors:
Marvel RE. Physics and Processing of Vanadium Dioxide for Optical Devices. [Doctoral Dissertation]. Vanderbilt University; 2016. Available from: http://hdl.handle.net/1803/10429
Vanderbilt University
12.
Gregory, Justin Mark.
Effect of Electron and Phonon Excitation on the Optical Properties of Indirect Gap Semiconductors.
Degree: PhD, Interdisciplinary Materials Science, 2013, Vanderbilt University
URL: http://hdl.handle.net/1803/10889
► The interaction of electrons and phonons with the properties of semiconducting crystals continues to be a fascinating and highly fruitful field of study. This dissertation…
(more)
▼ The interaction of electrons and phonons with the properties of semiconducting crystals continues to be a fascinating and highly fruitful field of study. This dissertation addresses two research problems under the general heading of electron and phonon effects on the optical properties of indirect gap semiconductors.
The first problem concerns nonlinear (multi-photon) absorption in germanium crystals, a topic of interest for the telecommunications industry as well as to the basic scientist. Using a combination of infrared transmittance experiments and numerical analysis, the two- and three-photon absorption coefficients β and γ for germanium have been evaluated over the range of wavelengths from 2.8 µm to 5.2 μm. The ratios of the coefficients across the direct/indirect gap transitions and between the two-and three-photon cases, which are less susceptible to experimental uncertainties than the absolute coefficients, have also been determined. Comparison with theoretical studies shows excellent agreement.
The second problem addresses the optical characteristics of ion-bombarded diamond crystals, which is a swiftly developing field due to diamond’s current status as the material of choice for hosting photonic and quantum information devices. The ultrafast optical technique known as coherent acoustic phonon interferometry has been applied to He ion irradiated diamond crystals for the purpose of determining the optical modification induced by the implantation damage. The experimental results provide information about the variation at in the complex refractive indices of the implanted specimens as well as the variation in the photoelastic tensor. A simple phenomenological model quantitatively describing the damage-induced optical modification has been developed which accurately predicts the experimental observations, and may prove to be a useful tool for quantum device design.
Advisors/Committee Members: Jim Davidson (committee member), Leonard Feldman (committee member), Timothy Hanusa (committee member), Sokrates Pantelides (committee member), Ronald Schrimpf (committee member), Norman Tolk (Committee Chair).
Subjects/Keywords: ion implantation; diamond; multiphoton absorption; germanium; refractive index; photoelasticity
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Gregory, J. M. (2013). Effect of Electron and Phonon Excitation on the Optical Properties of Indirect Gap Semiconductors. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/10889
Chicago Manual of Style (16th Edition):
Gregory, Justin Mark. “Effect of Electron and Phonon Excitation on the Optical Properties of Indirect Gap Semiconductors.” 2013. Doctoral Dissertation, Vanderbilt University. Accessed April 11, 2021.
http://hdl.handle.net/1803/10889.
MLA Handbook (7th Edition):
Gregory, Justin Mark. “Effect of Electron and Phonon Excitation on the Optical Properties of Indirect Gap Semiconductors.” 2013. Web. 11 Apr 2021.
Vancouver:
Gregory JM. Effect of Electron and Phonon Excitation on the Optical Properties of Indirect Gap Semiconductors. [Internet] [Doctoral dissertation]. Vanderbilt University; 2013. [cited 2021 Apr 11].
Available from: http://hdl.handle.net/1803/10889.
Council of Science Editors:
Gregory JM. Effect of Electron and Phonon Excitation on the Optical Properties of Indirect Gap Semiconductors. [Doctoral Dissertation]. Vanderbilt University; 2013. Available from: http://hdl.handle.net/1803/10889
Vanderbilt University
13.
Gren, Cameron Karl.
Synthesis and structures of main group organometallic complexes with sterically bulky allyl ligands.
Degree: PhD, Chemistry, 2009, Vanderbilt University
URL: http://hdl.handle.net/1803/13483
► This work focuses on the synthesis and characterization of substituted allyl complexes of alkali metals and post-transition elements. The use of bulky trimethylsilyl substituents on…
(more)
▼ This work focuses on the synthesis and characterization of substituted allyl complexes of alkali metals and post-transition elements. The use of bulky trimethylsilyl substituents on the allyl ligands has afforded isolable and thermally stable compounds of lithium, sodium, potassium, zinc, and gallium. The discussion of the resulting structurally characterized allyl-metal complexes focuses on the variation in bonding modes displayed by the allyl ligand. An attempt is made to determine a set of quantitative guidelines which can be used to classify the bonding in these and other similar organometallic complexes.
An additional interaction displayed by the group of alkali metal tris(allyl Œ)zincates described in this work is the propensity for cation-pi interactions between the pendant arms of the sigma-bonded allyl ligands and lithium, sodium, or potassium. This characteristic is explored both through experimental means (single crystal X-ray structure analysis and solution NMR spectroscopy) and through density functional theory calculations.
Advisors/Committee Members: Bridget Rogers (committee member), Eva Harth (committee member), David Wright (committee member), Charles Lukehart (committee member), Timothy Hanusa (Committee Chair).
Subjects/Keywords: cation-pi; alkali metal; zincate; organometallic; allyl; main group
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Gren, C. K. (2009). Synthesis and structures of main group organometallic complexes with sterically bulky allyl ligands. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/13483
Chicago Manual of Style (16th Edition):
Gren, Cameron Karl. “Synthesis and structures of main group organometallic complexes with sterically bulky allyl ligands.” 2009. Doctoral Dissertation, Vanderbilt University. Accessed April 11, 2021.
http://hdl.handle.net/1803/13483.
MLA Handbook (7th Edition):
Gren, Cameron Karl. “Synthesis and structures of main group organometallic complexes with sterically bulky allyl ligands.” 2009. Web. 11 Apr 2021.
Vancouver:
Gren CK. Synthesis and structures of main group organometallic complexes with sterically bulky allyl ligands. [Internet] [Doctoral dissertation]. Vanderbilt University; 2009. [cited 2021 Apr 11].
Available from: http://hdl.handle.net/1803/13483.
Council of Science Editors:
Gren CK. Synthesis and structures of main group organometallic complexes with sterically bulky allyl ligands. [Doctoral Dissertation]. Vanderbilt University; 2009. Available from: http://hdl.handle.net/1803/13483
Vanderbilt University
14.
Hansel, Rachael Ann.
Phosphor thermometry using rare-earth doped materials.
Degree: PhD, Interdisciplinary Materials Science, 2010, Vanderbilt University
URL: http://hdl.handle.net/1803/13826
► The goal of this work was to determine the luminescent lifetime of these phosphor materials as a function of temperature. Cerium-doped yttrium aluminum garnet and…
(more)
▼ The goal of this work was to determine the luminescent lifetime of these phosphor
materials as a function of temperature. Cerium-doped yttrium aluminum garnet and
europium-doped pyrochlores were synthesized using combustion synthesis. The
phosphors were characterized using X-ray diffraction, transmission electron microscopy,
and photoluminescence spectroscopy. Lifetime measurements were taken over a range of
temperatures. The garnet materials exhibited thermal quenching between 30-125 ◦ C . In
contrast, the pyrochlore materials did not exhibit thermal quenching until well past 300 ◦ C
. The results presented in this work have shown that high energy states, such as the charge
transfer state or the d -orbitals, play a key role in the thermal quenching properties of
materials. For Ce-doped materials, our results indicate that materials which cause the
splitting of the d -orbitals to increase will cause the emission from the d1
→ 4 f transition
to thermally quench at higher temperatures. The lifetime of the 5 D0
→ 4 f emission line of
Eu3+ is dependent on the location of the charge transfer state. We suggest that the reason
higher quenching temperature are observed in materials such as YBO3 : Eu and the other
pyrochlores is because these materials have high-energy charge transfer states. Tuning
Eu3+ materials to maximize the energy of the charge transfer state may improve thermal
quenching properties of thermographic phosphors.
Advisors/Committee Members: Charles Lukhart, Ph.D. (committee member), Richard Haglund, Ph.D. (committee member), Timothy Hanusa, Ph.D. (committee member), Stephen W. Allison, Ph.D. (committee member), D. Greg Walker, Ph.D. (Committee Chair).
Subjects/Keywords: thermometry; pyrochlores; garnets; luminescent lifetime; temperature; phosphors
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Hansel, R. A. (2010). Phosphor thermometry using rare-earth doped materials. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/13826
Chicago Manual of Style (16th Edition):
Hansel, Rachael Ann. “Phosphor thermometry using rare-earth doped materials.” 2010. Doctoral Dissertation, Vanderbilt University. Accessed April 11, 2021.
http://hdl.handle.net/1803/13826.
MLA Handbook (7th Edition):
Hansel, Rachael Ann. “Phosphor thermometry using rare-earth doped materials.” 2010. Web. 11 Apr 2021.
Vancouver:
Hansel RA. Phosphor thermometry using rare-earth doped materials. [Internet] [Doctoral dissertation]. Vanderbilt University; 2010. [cited 2021 Apr 11].
Available from: http://hdl.handle.net/1803/13826.
Council of Science Editors:
Hansel RA. Phosphor thermometry using rare-earth doped materials. [Doctoral Dissertation]. Vanderbilt University; 2010. Available from: http://hdl.handle.net/1803/13826
. 
Open Access Theses and Dissertations