+publisher:"Vanderbilt University" +contributor:("M. Douglas LeVan")

Vanderbilt University

1. Brodt, Matthew Ward. Electrospun Nanofiber Electrodes for Hydrogen/Air Proton Exchange Membrane Fuel Cells.

Degree: PhD, Chemical Engineering, 2015, Vanderbilt University

► Nanofiber particle/polymer cathode mats, with an average fiber diameter in the 400-600 nm range, were fabricated by electrospinning mixtures of a proton exchange polymer and… (more)

▼ Nanofiber particle/polymer cathode mats, with an average fiber diameter in the 400-600 nm range, were fabricated by electrospinning mixtures of a proton exchange polymer and commercial Pt/C catalyst particles, incorporated into membrane-electrode-assembles (MEAs), and evaluated in a fuel cell test fixture. Nanofiber cathodes with a commercial Pt/C catalyst and a binder of Nafion and poly(acrylic acid) (PAA) were shown to work extremely well in hydrogen/air fuel cell MEAs. As compared to conventional painted cathode MEAs, they had a higher electrochemical surface area (39-45 m2/g for nanofibers vs. 30-36 m2/g for painted), higher mass activity (~0.16 A/mgPt vs. 0.11 A/mgPt), and higher power output (e.g., 396 mW/cm2 at 0.65 V with H2/air at ambient pressure and a cathode Pt loading of 0.10 mg/cm2 vs. 292 mW/cm2). MEA power output with nanofiber cathodes was insensitive to changes in fiber diameter and Nafion/PAA binder composition, indicating that precise control of these parameters is not required for commercial scale-up. The nanofiber electrode architecture did not significantly change the way fuel cell cathodes degraded during load cycling tests (Pt dissolution tests), but the nanofibers had a clear advantage in power retention after accelerated durability tests that simulate start-stop cycling (carbon corrosion tests). A second generation of nanofiber cathodes was fabricated with a binder of Nafion and poly(vinylidene fluoride) (PVDF). The addition of PVDF altered the hydrophilicity/hydrophobicity of the cathode and slowed the deleterious effects of carbon corrosion. Carbon corrosion rates were the same for both nanofiber and painted Nafion/PVDF cathodes, but the effect of corrosion on power output was much less severe for nanofiber cathodes. Cathodes with a low Nafion/PVDF ratio produced low power initially but the power density increased over the course of a carbon corrosion test. This unusual result was associated with the formation of hydrophilic carbon oxidation species at the catalyst support surface, which increased the hydrophilicity of the cathode. Advisors/Committee Members: David E. Cliffel (committee member), M. Douglas LeVan (committee member), G. Kane Jennings (committee member), Peter N. Pintauro (Committee Chair).

Subjects/Keywords: fuel cells; cathodes; electrospinning; nanofiber electrodes; electrospun electrodes

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Brodt, M. W. (2015). Electrospun Nanofiber Electrodes for Hydrogen/Air Proton Exchange Membrane Fuel Cells. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/13333

Chicago Manual of Style (16^th Edition):

Brodt, Matthew Ward. “Electrospun Nanofiber Electrodes for Hydrogen/Air Proton Exchange Membrane Fuel Cells.” 2015. Doctoral Dissertation, Vanderbilt University. Accessed March 05, 2021. http://hdl.handle.net/1803/13333.

MLA Handbook (7^th Edition):

Brodt, Matthew Ward. “Electrospun Nanofiber Electrodes for Hydrogen/Air Proton Exchange Membrane Fuel Cells.” 2015. Web. 05 Mar 2021.

Vancouver:

Brodt MW. Electrospun Nanofiber Electrodes for Hydrogen/Air Proton Exchange Membrane Fuel Cells. [Internet] [Doctoral dissertation]. Vanderbilt University; 2015. [cited 2021 Mar 05]. Available from: http://hdl.handle.net/1803/13333.

Council of Science Editors:

Brodt MW. Electrospun Nanofiber Electrodes for Hydrogen/Air Proton Exchange Membrane Fuel Cells. [Doctoral Dissertation]. Vanderbilt University; 2015. Available from: http://hdl.handle.net/1803/13333

Vanderbilt University

2. Leamy, Alexandra Kathlene. Role of lipid metabolic pathways in the progression of hepatic lipotoxicity.

Degree: PhD, Chemical Engineering, 2015, Vanderbilt University

URL: http://hdl.handle.net/1803/11066

► The steady rise in Western obesity rates has been closely linked to significant increases in a multitude of accompanying health problems including obesity, type II… (more)

▼ The steady rise in Western obesity rates has been closely linked to significant increases in a multitude of accompanying health problems including obesity, type II diabetes and non-alcoholic fatty liver disease (NAFLD). NAFLD severity ranges from simple steatosis to acute steatohepatitis, but the molecular mechanisms controlling progression of this disease are poorly understood. The liver plays a central role in whole body homeostasis and, therefore, impairments in hepatic function are detrimental to a variety of biological processes. These hepatic dysfunctions are thought to be triggered by elevated free fatty acid flux from either dietary intake or adipose tissue efflux that results in etopic deposition of fat in the liver. It is known to be accompanied by increased signaling thorough cellular stress pathways, oxidant stress and eventual apoptosis. This phenotype is collectively termed hepatic lipotoxicity. Recent literature suggests that elevated free fatty acids (FFAs), especially saturated fatty acids (SFAs), play a central role in lipotoxic mechanisms, both in experimental models and in NAFLD patients. Relevant cellular processes that have been causally linked to lipotoxicity include endoplasmic reticulum (ER) stress, oxidative stress, mitochondrial dysfunction, and apoptosis. In contrast, increased triglyceride synthesis has been shown to have a protective effect against lipotoxicity, despite being one of the hallmark traits of NAFLD. The overarching theme of this dissertation is designing studies to better understand how the degree of intrahepatic lipid saturation controls cell fate in response to an elevated FFA load and the mechanisms through which these fatty acids act. Our results indicate that disordered phospholipid metabolism, specifically over saturation of membrane bilayers initiates a signaling cascade which culminates in cell death. Interventions designed to prevent saturation of the phospholipids improves hepatic cell fate when in environments of saturated fatty acid overload. Developing a more nuanced understanding of the molecular mechanisms underlying NAFLD progression will lead to more targeted and effective therapeutics for this increasingly prevalent disease, which to date has no proven pharmacologic treatment to prevent or reverse its course. Advisors/Committee Members: M. Douglas LeVan (committee member), David Wasserman (committee member), Scott Guelcher (committee member), Jamey Young (Committee Chair).

Subjects/Keywords: phospholipids; triglyceride synthesis; endoplasmic reticulum stress; saturated fatty acids; lipotoxicity; lipid metabolism

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Leamy, A. K. (2015). Role of lipid metabolic pathways in the progression of hepatic lipotoxicity. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/11066

Chicago Manual of Style (16^th Edition):

Leamy, Alexandra Kathlene. “Role of lipid metabolic pathways in the progression of hepatic lipotoxicity.” 2015. Doctoral Dissertation, Vanderbilt University. Accessed March 05, 2021. http://hdl.handle.net/1803/11066.

MLA Handbook (7^th Edition):

Leamy, Alexandra Kathlene. “Role of lipid metabolic pathways in the progression of hepatic lipotoxicity.” 2015. Web. 05 Mar 2021.

Vancouver:

Leamy AK. Role of lipid metabolic pathways in the progression of hepatic lipotoxicity. [Internet] [Doctoral dissertation]. Vanderbilt University; 2015. [cited 2021 Mar 05]. Available from: http://hdl.handle.net/1803/11066.

Council of Science Editors:

Leamy AK. Role of lipid metabolic pathways in the progression of hepatic lipotoxicity. [Doctoral Dissertation]. Vanderbilt University; 2015. Available from: http://hdl.handle.net/1803/11066

Vanderbilt University

3. House, Dustin L. Applications of the boundary-element method for electrokinetics in microfluidics.

Degree: PhD, Mechanical Engineering, 2012, Vanderbilt University

URL: http://hdl.handle.net/1803/10461

► The use of electric fields to control colloids has proven to be a promising form of actuation for microfluidic devices. However, limiting our ability to… (more)

▼ The use of electric fields to control colloids has proven to be a promising form of actuation for microfluidic devices. However, limiting our ability to exert precise control over colloidal samples using this technique is a lack of understanding of the complex situations of closely-bounded flow and non-spherical particle interaction. Considering the size and shape of biological particles and the size restraints of the channels in which they are contained, these situations are typically unavoidable. For these situations, exact solutions are often unavailable and finite-element methods can be inaccurate and inefficient for the highly distorted electric fields in narrow gap regions. To investigate these electrokinetic scenarios, we develop a boundary-element method (BEM). By reducing the dimension of the computational domain and utilizing quadrature integration, this technique is more efficient and can be much more accurate than volume meshes used by finite-element approaches. After linearizing the governing equations, the BEM is able elucidate the complex interaction among particle, electric field and flow field that is otherwise neglected by other commonly used approximations. We believe the BEM can be an efficient tool for microchannel design and optimization. Thus, the goal of this research is to advance its application within electrokinetics in microfluidics. This is done by developing a 2D and 3D code to simulate particle motion in the presence of electrophoresis, electroosmosis and dielectrophoresis. Three specific problems are considered. First, we model an electrophoretic particle bounded by two parallel walls. In this study, we find that for a tightly-bound particle, the viscous drag is comparable to its electrophoretic effect. Next, we model a particle traveling through a bent pore subject to a dielectrophoretic force. Here, we conclude that the particle's size has an increasingly significant effect on its lateral migration, especially when positioned close to the wall. The third application concerns the dielectrophoretic interaction of two slender particles and formation of particle chains. The two particles are found to realign themselves and then come together, forming a chaining pattern consistent to previous experimental observation. Advisors/Committee Members: M. Douglas LeVan (committee member), Jon Edd (committee member), Deyu Li (committee member), Haoxiang Luo (Committee Chair).

Subjects/Keywords: boundary-element method; electrokinetics; Microfluidics; lab-on-a-chip

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

House, D. L. (2012). Applications of the boundary-element method for electrokinetics in microfluidics. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/10461

Chicago Manual of Style (16^th Edition):

House, Dustin L. “Applications of the boundary-element method for electrokinetics in microfluidics.” 2012. Doctoral Dissertation, Vanderbilt University. Accessed March 05, 2021. http://hdl.handle.net/1803/10461.

MLA Handbook (7^th Edition):

House, Dustin L. “Applications of the boundary-element method for electrokinetics in microfluidics.” 2012. Web. 05 Mar 2021.

Vancouver:

House DL. Applications of the boundary-element method for electrokinetics in microfluidics. [Internet] [Doctoral dissertation]. Vanderbilt University; 2012. [cited 2021 Mar 05]. Available from: http://hdl.handle.net/1803/10461.

Council of Science Editors:

House DL. Applications of the boundary-element method for electrokinetics in microfluidics. [Doctoral Dissertation]. Vanderbilt University; 2012. Available from: http://hdl.handle.net/1803/10461

Vanderbilt University

4. Talley, Anne Douglas. Remodeling Characteristics and in vivo Healing of Low Viscosity Polyurethane Biocomposites for Bone Regeneration.

Degree: PhD, Chemical Engineering, 2016, Vanderbilt University

URL: http://hdl.handle.net/1803/11240

► Approximately 1.5 million bone grafting surgeries are performed annually in the United States for patients suffering traumatic injury, tumor, infection, or degenerative disease. The fiscal… (more)

▼ Approximately 1.5 million bone grafting surgeries are performed annually in the United States for patients suffering traumatic injury, tumor, infection, or degenerative disease. The fiscal burden of these procedures is staggering, with an estimated $215 billion annually associated with direct or indirect costs of musculoskeletal conditions. Current treatment options are limited by accessibility, ease of use, and graft remodeling characteristics. Low viscosity (LV) polyurethane biocomposites effectively heal bone defects in a variety of models and are potential candidates for the delivery of recombinant human bone morphogenetic protein-2 (rhBMP-2), a potent growth factor associated with bone remodeling. LV composites are injectable, settable grafts that are easy to deliver and support cellular infiltration and new bone deposition. The aim of this work was to develop low viscosity (LV) polyurethane biocomposites for bone regeneration and to test growth factor release and remodeling characteristics of the LV grafts in vitro and in vivo. The use of rhBMP-2 enhances cellular infiltration and tissue deposition when delivered to a defect site; however, efficacy can depend significantly on the physical and chemical properties of the chosen delivery system. RhBMP-2 release from the LV grafts in vivo was controlled by both Fickian diffusion and polymer degradation, which led to sustained release of growth factor as compared to the bolus release when delivered via a clinically available collagen sponge carrier. When LV grafts were delivered in vivo to both orthopaedic and craniomaxillofacial models, defect healing was enhanced by the introduction of inorganic ceramic particles that act as an osteoconductive scaffold. These compression resistant grafts were mechanically stable without the need for external fixation. Additionally, the remodeling characteristics of the LV grafts were studied to determine fundamental mechanisms of scaffold and matrix degradation. Degradation is partly dependent on active cellular response to the implanted bone graft, which influences both oxidative degradation and osteoclast resorption associated with polymer and ceramic remodeling respectively. Through these studies, the mechanisms of growth factor release and scaffold remodeling were discovered while also revealing the relevance of this system for clinical applications Advisors/Committee Members: Matthew J. Lang (committee member), Julie A. Sterling (committee member), M. Douglas LeVan (committee member), Scott A. Guelcher (Committee Chair).

Subjects/Keywords: bone graft; bone regeneration; polyurethane; osteoclast remodeling; compression resistant; growth factor

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Talley, A. D. (2016). Remodeling Characteristics and in vivo Healing of Low Viscosity Polyurethane Biocomposites for Bone Regeneration. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/11240

Chicago Manual of Style (16^th Edition):

Talley, Anne Douglas. “Remodeling Characteristics and in vivo Healing of Low Viscosity Polyurethane Biocomposites for Bone Regeneration.” 2016. Doctoral Dissertation, Vanderbilt University. Accessed March 05, 2021. http://hdl.handle.net/1803/11240.

MLA Handbook (7^th Edition):

Talley, Anne Douglas. “Remodeling Characteristics and in vivo Healing of Low Viscosity Polyurethane Biocomposites for Bone Regeneration.” 2016. Web. 05 Mar 2021.

Vancouver:

Talley AD. Remodeling Characteristics and in vivo Healing of Low Viscosity Polyurethane Biocomposites for Bone Regeneration. [Internet] [Doctoral dissertation]. Vanderbilt University; 2016. [cited 2021 Mar 05]. Available from: http://hdl.handle.net/1803/11240.

Council of Science Editors:

Talley AD. Remodeling Characteristics and in vivo Healing of Low Viscosity Polyurethane Biocomposites for Bone Regeneration. [Doctoral Dissertation]. Vanderbilt University; 2016. Available from: http://hdl.handle.net/1803/11240

Vanderbilt University

5. Tovar, Trenton Marcus. Adsorption Equilibria and Mass Transfer in Porous Adsorbents.

Degree: PhD, Chemical Engineering, 2016, Vanderbilt University

URL: http://hdl.handle.net/1803/11623

► Adsorption is an interfacial phenomenon in which intermolecular forces between a molecule and a surface create an adsorbed phase with different properties than the bulk… (more)

▼ Adsorption is an interfacial phenomenon in which intermolecular forces between a molecule and a surface create an adsorbed phase with different properties than the bulk fluid. Variation in the adsorbed phase among different adsorbate and solid adsorbent pairs is the driving force for many gas-phase separations. To efficiently design these separation processes, detailed characterization of the adsorbed phase over a range of operating conditions is required. The two main characteristics of the adsorbed phase that need to be well understood are adsorption equilibria and mass transfer rates, i.e. how much and how fast molecules are adsorbed. The purpose of this work is to use fundamental principles of adsorption to measure and interpret adsorption equilibria and mass transfer rates in various systems of interest. A concentration-swing frequency response (CSFR) method was used to measure mass transfer rates of a series of hydrocarbons in BPL activated carbon. Hydrocarbons with different ring and branched structures were used to test for steric effects on diffusion in the amorphous adsorbent. A correlation between rigid-ring structures and lower diffusivity was found. CSFR was also used to measure diffusion rates of CO2 in large single crystals of Cu-BTC, a metal-organic framework (MOF). Many MOFs have been studied as adsorbents for carbon capture and sequestration, but diffusion rates in the literature are scarce. The single crystal morphology of Cu-BTC allowed accurate measurements of micropore diffusion coefficients. Mass transfer rates were also measured on bidisperse pellets of a highly stable MOF, UiO-66, for CO2 and ethane. Macropore diffusion was determined to be the controlling resistance for both adsorbates. Volumetric methods were used to measure high pressure oxygen isotherms on a series of MOFs. MOFs with coordinatively unsaturated Cu metal sites were found to be promising candidates for oxygen storage, with capacities greater than current state of the art adsorbents. Finally, novel adsorbents were synthesized for a CO2 scrubber in a rebreather apparatus. The challenge for these adsorbents was obtaining high CO2 capacities at ambient temperatures, despite low CO2 partial pressures in water saturated conditions, while preventing mass transfer limitations. Advisors/Committee Members: Kenneth A. Debelak (committee member), Paul E. Laibinis (committee member), Eugene J. LeBoeuf (committee member), M. Douglas LeVan (Committee Chair).

Subjects/Keywords: Adsorption; mass transfer; metal-organic framework

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Tovar, T. M. (2016). Adsorption Equilibria and Mass Transfer in Porous Adsorbents. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/11623

Chicago Manual of Style (16^th Edition):

Tovar, Trenton Marcus. “Adsorption Equilibria and Mass Transfer in Porous Adsorbents.” 2016. Doctoral Dissertation, Vanderbilt University. Accessed March 05, 2021. http://hdl.handle.net/1803/11623.

MLA Handbook (7^th Edition):

Tovar, Trenton Marcus. “Adsorption Equilibria and Mass Transfer in Porous Adsorbents.” 2016. Web. 05 Mar 2021.

Vancouver:

Tovar TM. Adsorption Equilibria and Mass Transfer in Porous Adsorbents. [Internet] [Doctoral dissertation]. Vanderbilt University; 2016. [cited 2021 Mar 05]. Available from: http://hdl.handle.net/1803/11623.

Council of Science Editors:

Tovar TM. Adsorption Equilibria and Mass Transfer in Porous Adsorbents. [Doctoral Dissertation]. Vanderbilt University; 2016. Available from: http://hdl.handle.net/1803/11623

Vanderbilt University

6. Hall, Carl Alan. Instability of premixed lean hydrogen laminar tubular flames.

Degree: PhD, Mechanical Engineering, 2016, Vanderbilt University

URL: http://hdl.handle.net/1803/10671

► Combustion at the conditions found in practical applications is extremely complex and must be well characterized to support the next generation of combustors. This task… (more)

▼ Combustion at the conditions found in practical applications is extremely complex and must be well characterized to support the next generation of combustors. This task is extremely difficult both experimentally and numerically, where the fast timescales and small spatial scales restrict complete characterization. This complexity is mitigated for numerical simulations through the use of computationally efficient models that approximate problem physics. Limitations arise in validating these approximations, due to the inability to experimentally measure the required quantities combined with the prohibitive numerical cost of performing detailed simulations. Fundamental investigations address this difficulty—simplified flame geometries can be examined in more complete detail and can be used to support the validation of modeling approximations. Presented here is the experimental and numerical characterization of premixed laminar tubular flames fueled with dilute lean hydrogen mixtures. This fundamental flame geometry exhibits structure similar to practical turbulent flames (locally varying curvature with extinction zones), yet retains a time independent 2D planar structure. This aspect greatly reduces the experimental and computational requirements, permitting: (1) a more complete experimental and numerical characterization and (2) detailed numerical experiments to directly validate modeling approximations. Experimental measurements using non-intrusive laser diagnostic techniques are presented that provide 2D spatially resolved and quantitative measurements of temperature, major species, and two minor species (H and OH) through flame cross-sections. The detailed flame structure is then simulated using a 2D fully-implicit primitive variable finite difference formulation that includes multicomponent transport and detailed chemical kinetics. Comparisons between the experimental and numerical data sets are presented and show overall good agreement, though with significant quantitative discrepancies. These discrepancies are examined, and are further investigated with numerical experiments to better elucidate the dependence of cellular flame appearance on experimentally controlled variables. The cellular tubular flame is found to be highly sensitive geometry that may be used for validating diffusive transport modeling approximations. This capability is exemplified through the development of a simple and accurate approximation for thermal diffusion (i.e. Soret effect) that is suitable for practical combustion codes. Advisors/Committee Members: Haoxiang Luo (committee member), M. Douglas LeVan (committee member), Amrutur V. Anilkumar (committee member), Deyu Li (committee member), Robert W. Pitz (Committee Chair).

Subjects/Keywords: laser diagnostics; laminar flame; thermal-diffusive instability; cellular flame

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Hall, C. A. (2016). Instability of premixed lean hydrogen laminar tubular flames. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/10671

Chicago Manual of Style (16^th Edition):

Hall, Carl Alan. “Instability of premixed lean hydrogen laminar tubular flames.” 2016. Doctoral Dissertation, Vanderbilt University. Accessed March 05, 2021. http://hdl.handle.net/1803/10671.

MLA Handbook (7^th Edition):

Hall, Carl Alan. “Instability of premixed lean hydrogen laminar tubular flames.” 2016. Web. 05 Mar 2021.

Vancouver:

Hall CA. Instability of premixed lean hydrogen laminar tubular flames. [Internet] [Doctoral dissertation]. Vanderbilt University; 2016. [cited 2021 Mar 05]. Available from: http://hdl.handle.net/1803/10671.

Council of Science Editors:

Hall CA. Instability of premixed lean hydrogen laminar tubular flames. [Doctoral Dissertation]. Vanderbilt University; 2016. Available from: http://hdl.handle.net/1803/10671

Vanderbilt University

7. Mitchell, Lucas Alexander. Adsorption of light gases and gas mixtures on zeolites and nanoporous carbons.

Degree: PhD, Chemical Engineering, 2014, Vanderbilt University

URL: http://hdl.handle.net/1803/10942

► The ability to accurately predict mixture adsorption equilibrium is vital for future gas separation technologies. This research concentrates on the investigation and prediction of adsorption… (more)

▼ The ability to accurately predict mixture adsorption equilibrium is vital for future gas separation technologies. This research concentrates on the investigation and prediction of adsorption equilibrium of pure components and gas mixtures. The systems studied are of importance to the field of personal medical oxygen generation. Two commercial adsorbents are investigated: a LiLSX zeolite and a carbon molecular sieve. Adsorption equilibria are measured on the LiLSX zeolite for nitrogen and oxygen, both as pure gases and binary mixtures. The binary measurements consist of Henry’s law behavior with one component in excess as well as binary isotherms for a range of compositions. Binary Henry’s law behavior is modeled by adding virial excess mixture coefficients to the ideal adsorbed solution theory. The mixture coefficients are evaluated solely from the binary Henry’s law behavior, and the binary isotherms for a range of compositions are predicted accurately. Adsorption isotherms are measured on the carbon molecular sieve for oxygen, nitrogen, and argon at pressures up to 100 bar. The capacities of the gases are higher than expected, with the carbon molecular sieve having capacities higher than BPL activated carbon and capacities similar to a superactivated carbon. An approach to model adsorption of pure gases using classical density functional theory is developed. Fundamental measure theory is used as an accurate method to describe the hard sphere interaction potential. To address the intermolecular and intramolecular attractive potentials, a version of the statistical associating fluid theory is used. The new approach models adsorption of molecules of increasing complexity on flat walls, with predictions comparing well with simulation data in the literature. The new approach is extended by incorporating the 10-4-3 Steele potential to describe slit-shaped carbon pores. Nitrogen is first modeled inside the pores, where the density profiles are combined to produce a pore size distribution and describe the nitrogen isotherm. Pore density profiles are modeled for n-pentane and, using the pore size distribution obtained from nitrogen, a pentane isotherm is shown to agree well with experimental data. Advisors/Committee Members: G. Kane Jennings (committee member), Peter T. Cummings (committee member), Sandra J. Rosenthal (committee member), M. Douglas LeVan (Committee Chair).

Subjects/Keywords: DFT; Henrys Law; mixtures; adsorption; zeolites; carbon

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Mitchell, L. A. (2014). Adsorption of light gases and gas mixtures on zeolites and nanoporous carbons. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/10942

Chicago Manual of Style (16^th Edition):

Mitchell, Lucas Alexander. “Adsorption of light gases and gas mixtures on zeolites and nanoporous carbons.” 2014. Doctoral Dissertation, Vanderbilt University. Accessed March 05, 2021. http://hdl.handle.net/1803/10942.

MLA Handbook (7^th Edition):

Mitchell, Lucas Alexander. “Adsorption of light gases and gas mixtures on zeolites and nanoporous carbons.” 2014. Web. 05 Mar 2021.

Vancouver:

Mitchell LA. Adsorption of light gases and gas mixtures on zeolites and nanoporous carbons. [Internet] [Doctoral dissertation]. Vanderbilt University; 2014. [cited 2021 Mar 05]. Available from: http://hdl.handle.net/1803/10942.

Council of Science Editors:

Mitchell LA. Adsorption of light gases and gas mixtures on zeolites and nanoporous carbons. [Doctoral Dissertation]. Vanderbilt University; 2014. Available from: http://hdl.handle.net/1803/10942

Vanderbilt University

8. Templeton, Neil Andrew. 13C metabolic flux analysis of recombinant Chinese hamster ovary (CHO) cell cultures.

Degree: PhD, Chemical Engineering, 2014, Vanderbilt University

URL: http://hdl.handle.net/1803/14754

► We have applied 13C metabolic flux analysis (13C MFA) to develop a system-wide understanding of the central carbon metabolism of Chinese hamster ovary (CHO) cells,… (more)

▼ We have applied 13C metabolic flux analysis (13C MFA) to develop a system-wide understanding of the central carbon metabolism of Chinese hamster ovary (CHO) cells, the most widely used host for industrial production of monoclonal antibodies (mAbs) and other therapeutic proteins. First, we assessed dynamic changes in CHO metabolism during four different stages of a fed-batch culture to discover metabolic phenotypes that were associated with peak mAb productivity. While glycolytic metabolism dominated during the initial growth phase, enhanced oxidative metabolism involving increased citric acid cycle (CAC) flux and oxidative pentose phosphate pathway (oxPPP) activity prevailed during later phases when mAb production was highest. Next, we applied 13C MFA to examine CHO lines that had been engineered to express Bcl-2Δ, an engineered anti-apoptotic protein, to elucidate its impact on cell growth and metabolism. Not only was integrated viable cell density (IVCD) and culture longevity increased by Bcl-2Δ, but the intracellular fate of pyruvate was significantly altered over the entire course of a batch culture. More pyruvate was oxidized by mitochondrial CAC metabolism during the initial lactate-producing phase, and more lactate was consumed relative to glucose during the later lactate-consuming phase of culture. Finally, 13C MFA was applied to compare the metabolic phenotypes of nine different mAb secreting CHO lines, as well as three non-producing host lines. Among four clones that did not express Bcl-2Δ, a linear correlation was found between specific antibody productivity and total NADH production (an indicator of oxidative metabolism). Expression of Bcl-2Δ led to a general increase in NADH production that was accompanied by even greater specific mAb productivity. Overall, an in-depth quantification of CHO intracellular metabolism was accomplished by this dissertation, with multiple findings that are applicable to industrial antibody production. Advisors/Committee Members: M. Douglas LeVan (committee member), Scott A. Guelcher (committee member), David L. Tabb (committee member), Jamey D. Young (Committee Chair).

Subjects/Keywords: bioreactor; metabolism; lactate; CHO; MFA; monoclonal antibody production

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Templeton, N. A. (2014). 13C metabolic flux analysis of recombinant Chinese hamster ovary (CHO) cell cultures. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/14754

Chicago Manual of Style (16^th Edition):

Templeton, Neil Andrew. “13C metabolic flux analysis of recombinant Chinese hamster ovary (CHO) cell cultures.” 2014. Doctoral Dissertation, Vanderbilt University. Accessed March 05, 2021. http://hdl.handle.net/1803/14754.

MLA Handbook (7^th Edition):

Templeton, Neil Andrew. “13C metabolic flux analysis of recombinant Chinese hamster ovary (CHO) cell cultures.” 2014. Web. 05 Mar 2021.

Vancouver:

Templeton NA. 13C metabolic flux analysis of recombinant Chinese hamster ovary (CHO) cell cultures. [Internet] [Doctoral dissertation]. Vanderbilt University; 2014. [cited 2021 Mar 05]. Available from: http://hdl.handle.net/1803/14754.

Council of Science Editors:

Templeton NA. 13C metabolic flux analysis of recombinant Chinese hamster ovary (CHO) cell cultures. [Doctoral Dissertation]. Vanderbilt University; 2014. Available from: http://hdl.handle.net/1803/14754

Vanderbilt University

9. Wan, Li. Understanding the Nanoconfined Fluid via Absolute Free Energy Determination.

Degree: PhD, Chemical Engineering, 2015, Vanderbilt University

URL: http://hdl.handle.net/1803/10898

► In recent years, the development of microelectromechanical systems (MEMS) and nanoelectromechanical systems (NEMS) has received intense attention and effort. However, studies on nanoconfined fluid phase… (more)

▼ In recent years, the development of microelectromechanical systems (MEMS) and nanoelectromechanical systems (NEMS) has received intense attention and effort. However, studies on nanoconfined fluid phase behavior has given rise to a vigorous debate that began in the early 1990s. While experiments by Klein and coworkers suggest the formation of a nanoconfinement-induced solid phase as the separation of two solid walls is reduced below seven molecular layers, experiments by Granick and coworkers instead suggest that a glassy state is formed, since no yield stress was observed in their experiment and the measured viscosity increase is significantly smaller. Simulation studies have intrinsic molecular resolution and hence no such observational problems, but the lack of a clear demonstration that the observed solid-like structure is an equilibrated structure, has hindered wide acceptance of the results of these studies. To determine whether a structure is metastable, the key measurement required is the free energy of the system. We concentrate our studies on development and applications of absolute free energy calculation methodology, specifically for nanoconfined systems, and uses the absolute free energy to reach a conclusive understanding of nanoconfined fluid phase behavior. Based on free energy measurements conducted in this dissertation research, we reveal the thermodynamic role of wall-fluid interaction, wall-wall separation and fluid-wall particle size ratio, in determining nanoconfined phase behavior. Finally, according to investigations on the central layers of nanoconfined system with artificially increased density, we demonstrate the potential of jammed atoms in destabilizing the nanoconfinement-induced solid structure. This finding suggests one possible explanation of the divergent experimental results. In this picture, we find there are discrete solid states at separations around integer numbers of ideal layers, as opposed to a conventional fluid-solid transition. Advisors/Committee Members: Clare M. McCabe (committee member), M. Douglas LeVan (committee member), Terry P. Lybrand (committee member), Peter T. Cummings (Committee Chair).

Subjects/Keywords: Nanoconfined Fluid; Phase Transition; Free Energy

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Wan, L. (2015). Understanding the Nanoconfined Fluid via Absolute Free Energy Determination. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/10898

Chicago Manual of Style (16^th Edition):

Wan, Li. “Understanding the Nanoconfined Fluid via Absolute Free Energy Determination.” 2015. Doctoral Dissertation, Vanderbilt University. Accessed March 05, 2021. http://hdl.handle.net/1803/10898.

MLA Handbook (7^th Edition):

Wan, Li. “Understanding the Nanoconfined Fluid via Absolute Free Energy Determination.” 2015. Web. 05 Mar 2021.

Vancouver:

Wan L. Understanding the Nanoconfined Fluid via Absolute Free Energy Determination. [Internet] [Doctoral dissertation]. Vanderbilt University; 2015. [cited 2021 Mar 05]. Available from: http://hdl.handle.net/1803/10898.

Council of Science Editors:

Wan L. Understanding the Nanoconfined Fluid via Absolute Free Energy Determination. [Doctoral Dissertation]. Vanderbilt University; 2015. Available from: http://hdl.handle.net/1803/10898

Vanderbilt University

10. Harl, Robert Randall, Jr. Processing considerations for the combustion synthesis of yttrium aluminum garnet powders.

Degree: PhD, Chemical Engineering, 2013, Vanderbilt University

URL: http://hdl.handle.net/1803/15039

► Combustion synthesis leverages the exothermic reaction between a fuel and an oxidizer to provide the energy needed to form crystalline refractory oxides. In many cases… (more)

▼ Combustion synthesis leverages the exothermic reaction between a fuel and an oxidizer to provide the energy needed to form crystalline refractory oxides. In many cases combustion syntheses are less energy intensive and require fewer processing steps than traditional ceramic oxide processes. However, the properties of materials produced by combustion syntheses can depend on many processing parameters, such as the type of fuel used, the fuel to oxidizer ratio, coordinating characteristics of the fuel, the rate of heating the reactant solution. This work reports the results of process optimization and materials characterization studies of three ceramic oxides: yttrium aluminum garnet (YAG), lanthanum zirconate (LZO) and yttrium borate (YBO). Cerium and/or europium dopants were incorporated into these three host lattices to enhance their photoluminescent (PL) properties. The effects of process parameters on the crystallinity, composition, and PL emission intensity of the synthesized materials were investigated. We show that mixing urea and citric acid fuels decreases the PL intensity of YAG:Ce1% compared to using either pure urea or pure citric acid. Characterization of the material found that the material synthesized using only citric acid contained the most YAG phase and that the decrease in PL intensity is likely due to dopant segregation. We show that the heating rate used to raise the reactant solution to the ignition temperature also affected the crystallinity of the synthesized material. Thermogravimetric analysis and differential scanning calorimetry identified a heating rate that produced the maximum heat of combustion. Transmission electron micrographs of the synthesized material show that heating rates affect the morphology of the material. The YBO process optimization involved adding additional fuel and oxidizer to compensate for the lack of a boron-based oxidizer and included a post-synthesis anneal. The effect of proton irradiation on the PL of these materials was tested. The PL of YAG and LZO was not affected by a fluence of 1x10¹⁶ protons/cm², however the PL intensity of YBO decreased with doses of 1x10¹⁴ protons/cm² and above. Advisors/Committee Members: D. Greg Walker (committee member), Kenneth Debelak (committee member), M. Douglas LeVan (committee member), Bridget R. Rogers (Committee Chair).

Subjects/Keywords: YAG; TGA; thermogravimetric analysis; combustion synthesis; differential scanning calorimetry; photoluminescence; XRD; DSC; XPS

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Harl, Robert Randall, J. (2013). Processing considerations for the combustion synthesis of yttrium aluminum garnet powders. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/15039

Chicago Manual of Style (16^th Edition):

Harl, Robert Randall, Jr. “Processing considerations for the combustion synthesis of yttrium aluminum garnet powders.” 2013. Doctoral Dissertation, Vanderbilt University. Accessed March 05, 2021. http://hdl.handle.net/1803/15039.

MLA Handbook (7^th Edition):

Harl, Robert Randall, Jr. “Processing considerations for the combustion synthesis of yttrium aluminum garnet powders.” 2013. Web. 05 Mar 2021.

Vancouver:

Harl, Robert Randall J. Processing considerations for the combustion synthesis of yttrium aluminum garnet powders. [Internet] [Doctoral dissertation]. Vanderbilt University; 2013. [cited 2021 Mar 05]. Available from: http://hdl.handle.net/1803/15039.

Council of Science Editors:

Harl, Robert Randall J. Processing considerations for the combustion synthesis of yttrium aluminum garnet powders. [Doctoral Dissertation]. Vanderbilt University; 2013. Available from: http://hdl.handle.net/1803/15039

Vanderbilt University

11. Giesy, Timothy Joel. Characterization of mass transfer in adsorbents for use in oxygen separation from air.

Degree: PhD, Chemical Engineering, 2014, Vanderbilt University

URL: http://hdl.handle.net/1803/10939

► Production of high-purity oxygen from air by pressure-swing adsorption (PSA) is of interest for a variety of applications. One recognized area for which this technology… (more)

▼ Production of high-purity oxygen from air by pressure-swing adsorption (PSA) is of interest for a variety of applications. One recognized area for which this technology could be particularly useful is the development of a source of medical oxygen for ill or injured astronauts. Currently, medical oxygen in space is provided in the form of compressed oxygen tanks, which are heavy, offer a limited supply of oxygen, and can cause the oxygen concentration limit in the atmosphere of the International Space Station to be exceeded. Oxygen separation by PSA offers potential solutions to each of these problems, but current PSA technologies are still too large and energy-inefficient to be employed in space. Of fundamental importance to the development of next-generation PSA technologies that can meet the demands of space-related applications is the characterization of the adsorption rates of atmospheric gases on new adsorbents. Frequency response (FR) techniques are among the most effective techniques for studying adsorption rates, as they are able to distinguish between different transport mechanisms that can govern the rate of adsorption. This work comprises FR studies of adsorption rates in gas/adsorbent systems that are vital to the development of rapid PSA technologies designed to produce high-purity oxygen from air. First, a novel apparatus is presented, which is capable of performing three different types of FR experiments. Then, the new apparatus is used to characterize adsorption rates of CO2 on 13X zeolite; pure O2, N2, and Ar on carbon molecular sieve (CMS); binary mixtures of O2 and Ar on CMS; and O2 and N2 on LiX zeolite. In these systems, the governing transport mechanisms are identified and useful rate parameters are measured. The insights gained through this work should prove useful to the advancement of PSA-based oxygen purification technologies and should also contribute significantly to the broader aim of advancing the present understanding of gas transport in adsorbents. Advisors/Committee Members: Kenneth A. Debelak (committee member), Peter N. Pintauro (committee member), Eugene J. LeBoeuf (committee member), M. Douglas LeVan (Committee Chair).

Subjects/Keywords: gas diffusion; adsorption dynamics

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Giesy, T. J. (2014). Characterization of mass transfer in adsorbents for use in oxygen separation from air. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/10939

Chicago Manual of Style (16^th Edition):

Giesy, Timothy Joel. “Characterization of mass transfer in adsorbents for use in oxygen separation from air.” 2014. Doctoral Dissertation, Vanderbilt University. Accessed March 05, 2021. http://hdl.handle.net/1803/10939.

MLA Handbook (7^th Edition):

Giesy, Timothy Joel. “Characterization of mass transfer in adsorbents for use in oxygen separation from air.” 2014. Web. 05 Mar 2021.

Vancouver:

Giesy TJ. Characterization of mass transfer in adsorbents for use in oxygen separation from air. [Internet] [Doctoral dissertation]. Vanderbilt University; 2014. [cited 2021 Mar 05]. Available from: http://hdl.handle.net/1803/10939.

Council of Science Editors:

Giesy TJ. Characterization of mass transfer in adsorbents for use in oxygen separation from air. [Doctoral Dissertation]. Vanderbilt University; 2014. Available from: http://hdl.handle.net/1803/10939

Vanderbilt University

12. McNew, Coy Phillip. The Attachment of Colloidal Particles to Environmentally Relevant Surfaces: Effect of Ionic Strength, Particle Shape, and Physicochemical Properties.

Degree: PhD, Environmental Engineering, 2015, Vanderbilt University

URL: http://hdl.handle.net/1803/15082

► The sharp increase in production of engineered nanomaterials (ENMs) combined with their high potential for aquatic toxicity, mean that understanding the transport of these materials… (more)

▼ The sharp increase in production of engineered nanomaterials (ENMs) combined with their high potential for aquatic toxicity, mean that understanding the transport of these materials throughout the environment is of utmost importance. In the presence of environmentally relevant surfaces, the relationship between particle attachment and relevant variables was quantitatively investigated and reported. Increasing temperature greatly altered the attachment onto two different humic substances by altering the hydration, and therefore confirmation, of the natural organic matter (NOM) matrix. By increasing the hydration of the NOM layer, the matrix swelled, allowing for more surface area for particle attachment and an increase in possible sorption sites. Similarly, high ionic strengths caused the NOM layer to condense, reducing surface area and sorption sites for particle attachment and effectively lowering particle attachment efficiency. The shape of the particle itself also played a role in attachment. A humic acid layer showed preference to smaller, more spherical particles due to the size of the voids within the layer, raising attachment efficiency for the smaller, spherical particles only, while a smoother, more condensed layer did not. As ionic strength increased, however, the layer condensed and the preference vanished. Finally, a predictive model for attachment efficiency was developed using a machine learning approach and trained on a database containing all the data gathered in this work combined with all currently available, relevant attachment efficiency literature. The model employed 13 training features, each of which was a physicochemical characteristic of the particle, surface, or solution system, to predict attachment efficiency with relatively high performance. The most important features for predicting attachment efficiency were also identified. The results presented in this work improve the understanding of particle attachment efficiency by identifying important variables, explaining why these variables have an effect on attachment efficiency, and also providing an empirical predictive model for attachment efficiency. By applying this approach to other areas of particle transport, we can close the gap between experimental and modeling efforts, advancing transport knowledge as quickly and efficiently as possible. Only by closing this gap can we expect to understand particle transport in a system as complex as the natural environment. Advisors/Committee Members: Yusong Li (committee member), Alan Bowers (committee member), M. Douglas LeVan (committee member), George Hornberger (committee member), Eugene J. LeBoeuf (Committee Chair).

Subjects/Keywords: transport; nanoparticle; nanomaterial; colloid; QCM; machine learning

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

McNew, C. P. (2015). The Attachment of Colloidal Particles to Environmentally Relevant Surfaces: Effect of Ionic Strength, Particle Shape, and Physicochemical Properties. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/15082

Chicago Manual of Style (16^th Edition):

McNew, Coy Phillip. “The Attachment of Colloidal Particles to Environmentally Relevant Surfaces: Effect of Ionic Strength, Particle Shape, and Physicochemical Properties.” 2015. Doctoral Dissertation, Vanderbilt University. Accessed March 05, 2021. http://hdl.handle.net/1803/15082.

MLA Handbook (7^th Edition):

McNew, Coy Phillip. “The Attachment of Colloidal Particles to Environmentally Relevant Surfaces: Effect of Ionic Strength, Particle Shape, and Physicochemical Properties.” 2015. Web. 05 Mar 2021.

Vancouver:

McNew CP. The Attachment of Colloidal Particles to Environmentally Relevant Surfaces: Effect of Ionic Strength, Particle Shape, and Physicochemical Properties. [Internet] [Doctoral dissertation]. Vanderbilt University; 2015. [cited 2021 Mar 05]. Available from: http://hdl.handle.net/1803/15082.

Council of Science Editors:

McNew CP. The Attachment of Colloidal Particles to Environmentally Relevant Surfaces: Effect of Ionic Strength, Particle Shape, and Physicochemical Properties. [Doctoral Dissertation]. Vanderbilt University; 2015. Available from: http://hdl.handle.net/1803/15082

Vanderbilt University

13. Furtado, Amanda M. B. Novel Nanoporous Composite Materials for Light Gas Adsorption.

Degree: PhD, Chemical Engineering, 2012, Vanderbilt University

URL: http://hdl.handle.net/1803/11404

► This research addresses the synthesis and development of biphasic, nanoporous composite materials for use in single pass filters of various types for the removal of… (more)

▼ This research addresses the synthesis and development of biphasic, nanoporous composite materials for use in single pass filters of various types for the removal of light acidic and basic gases from humid air. Potential applications of the new adsorbent materials range from military and first responder protective masks to industrial filters. Research into several different composite materials is considered, including mesoporous silica impregnated with metal salts, a metal organic phase, carbonaceous phases, and organoalkoxysilanes. The research also includes an organoalkoxysilane-modified zirconium hydroxide composite. The materials are characterized using a plethora of analytical techniques including nitrogen isotherms, BET surface areas, X-ray diffraction, thermogravimetric analysis, X-ray photoelectron spectroscopy, scanning electron microscopy, and Fourier transform infrared spectroscopy. They are also tested for light gas capacities of ammonia and sulfur dioxide using a breakthrough apparatus. Of the materials reviewed in this work, the organoalkoxysilane-modified composites exhibit the highest single pass capacities for sulfur dioxide, a representative acidic gas, and ammonia, a representative basic gas. A siliceous MCM-41 support provides high capacity for ammonia, and a zirconium hydroxide support provides high capacity for sulfur dioxide. Functional groups including carbonyls and amines grafted onto the supports provide ammonia and sulfur dioxide capacity, respectively. Two organoalkoxysilane molecules have also been grafted onto the supports to optimize the capacities. For example, MCM-41 has been grafted with 3-aminopropyltriethoxysilane, which contains an amine functional group, as well as 3-triethoxypropylsilyl isocyanate, which contains a carbonyl group, to produce an adsorbent with high capacities for both sulfur dioxide and ammonia. The resulting biphasic materials have high adsorption capacities for these gases, and the adsorbents can be easily tuned to capture a predominant amount of either gas. Advisors/Committee Members: Scott Guelcher (committee member), G. Kane Jennings (committee member), Bridget Rogers (committee member), Eugene LeBoeuf (committee member), M. Douglas LeVan (Committee Chair).

Subjects/Keywords: chemisorption; MCM-41; nanoporous composites; toxic industrial chemicals; adsorption; ordered mesoporous silica

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Furtado, A. M. B. (2012). Novel Nanoporous Composite Materials for Light Gas Adsorption. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/11404

Chicago Manual of Style (16^th Edition):

Furtado, Amanda M B. “Novel Nanoporous Composite Materials for Light Gas Adsorption.” 2012. Doctoral Dissertation, Vanderbilt University. Accessed March 05, 2021. http://hdl.handle.net/1803/11404.

MLA Handbook (7^th Edition):

Furtado, Amanda M B. “Novel Nanoporous Composite Materials for Light Gas Adsorption.” 2012. Web. 05 Mar 2021.

Vancouver:

Furtado AMB. Novel Nanoporous Composite Materials for Light Gas Adsorption. [Internet] [Doctoral dissertation]. Vanderbilt University; 2012. [cited 2021 Mar 05]. Available from: http://hdl.handle.net/1803/11404.

Council of Science Editors:

Furtado AMB. Novel Nanoporous Composite Materials for Light Gas Adsorption. [Doctoral Dissertation]. Vanderbilt University; 2012. Available from: http://hdl.handle.net/1803/11404

Vanderbilt University

14. Barpaga, Dushyant. Synthesis and Characterization of Novel Nanoporous Materials for Acidic and Basic Gas Adsorption.

Degree: PhD, Chemical Engineering, 2016, Vanderbilt University

URL: http://hdl.handle.net/1803/10870

► Adsorbent technology employing specificity towards a broad range of target molecules is becoming increasingly important for a variety of applications such as filtration, separation, purification… (more)

▼ Adsorbent technology employing specificity towards a broad range of target molecules is becoming increasingly important for a variety of applications such as filtration, separation, purification and/or storage of fluids. The development of newer, more efficient adsorbent materials is a growing concern for civilian, first responder, and military uses. This dissertation is focused on the synthesis and characterization of novel, nanoporous adsorbents incorporated with metal salts either by further functionalization of pre-synthesized substrates or as precursors in the formation of porous composites like metal-organic frameworks (MOFs). The biphasic substrate primarily used in this work was made up of mesoporous silica derived from MCM-41 and a microporous carbon made from a polymerized alcohol. This carbon silica composite (CSC) was further functionalized by various water-soluble metal salts through single salt impregnations as well as dual salt incorporation. The effectiveness of salt-functionalized CSCs was measured via breakthrough capacities for low concentrations of NH3 and SO2. Materials with high adsorption performance for both of these targets, representative of acidic and basic gases, were obtained with potential broad-scale, commercial applicability for a diverse set of adsorbates. In brief, the incorporation of potassium carbonate increased the alkalinity of the adsorbent thereby promoting SO2 adsorption. Similarly, the incorporation of zinc chloride increased the acidity of the adsorbent resulting in enhanced NH3 adsorption. The addition of K2CO3 and ZnCl2 on the same adsorbent was shown to consolidate high adsorption performance for both of these toxic industrial chemicals (TICs). Interestingly, upon incorporation of the two water-soluble impregnants, a reaction to form an insoluble precipitate within the substrate via in-pore synthesis occurs. This dual salt functionalization leading to the in-pore synthesis of insoluble precipitates was also performed using various combinations of metal chlorides with potassium salts. Differences in the pH of salt-incorporated substrates provided an understanding of cation and anion dependence in functionalized materials for NH3 and SO2 adsorption. With MOFs, a characterization analysis was performed to interpret the degradation (or lack thereof) of chemical bonds within the framework that were susceptible to water adsorption. Advisors/Committee Members: Peter N. Pintauro (committee member), Sandra J. Rosenthal (committee member), G. Kane Jennings (committee member), M. Douglas LeVan (Committee Chair).

Subjects/Keywords: adsorbent materials; NH3; SO2; MOFs; metal salts; CSC; MCM-41

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Barpaga, D. (2016). Synthesis and Characterization of Novel Nanoporous Materials for Acidic and Basic Gas Adsorption. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/10870

Chicago Manual of Style (16^th Edition):

Barpaga, Dushyant. “Synthesis and Characterization of Novel Nanoporous Materials for Acidic and Basic Gas Adsorption.” 2016. Doctoral Dissertation, Vanderbilt University. Accessed March 05, 2021. http://hdl.handle.net/1803/10870.

MLA Handbook (7^th Edition):

Barpaga, Dushyant. “Synthesis and Characterization of Novel Nanoporous Materials for Acidic and Basic Gas Adsorption.” 2016. Web. 05 Mar 2021.

Vancouver:

Barpaga D. Synthesis and Characterization of Novel Nanoporous Materials for Acidic and Basic Gas Adsorption. [Internet] [Doctoral dissertation]. Vanderbilt University; 2016. [cited 2021 Mar 05]. Available from: http://hdl.handle.net/1803/10870.

Council of Science Editors:

Barpaga D. Synthesis and Characterization of Novel Nanoporous Materials for Acidic and Basic Gas Adsorption. [Doctoral Dissertation]. Vanderbilt University; 2016. Available from: http://hdl.handle.net/1803/10870

Vanderbilt University

15. Tedjo, Chrysanty. Controlling protein-surface interactions in chromatography using mixed self-assembled monolayers.

Degree: PhD, Chemical Engineering, 2011, Vanderbilt University

URL: http://hdl.handle.net/1803/11289

► High performance liquid chromatography (HPLC) has become an essential tool in biotechnology. Numerous proteins have been separated by HPLC for analytical and preparative separation purposes.… (more)

▼ High performance liquid chromatography (HPLC) has become an essential tool in biotechnology. Numerous proteins have been separated by HPLC for analytical and preparative separation purposes. The main challenge in protein chromatography is the ability to isolate the protein of interest in its active form with high purity. The goal of this research is to provide a generic chromatographic approach for separating proteins efficiently with high retention of their biological activity. Here, I utilized mixed self self-assembled monolayers (SAMs) of Cl3Si(CH2)11(OCH2CH2)3OCH3 (EG3OMe) and n-octyltrichlorosilane (C8) to modulate protein-silica support interactions in a controlled manner. The oligo(ethylene glycol) tail groups in the EG3OMe SAM display a surface hydrophilicity that minimizes interactions with proteins. The C8 SAM displays a hydrophobic surface that adsorbs proteins. With mixed SAMs, the wetting properties of their surface and their level of interactions with proteins can be controlled. Mixed SAMs of EG3OMe and C8 were deposited on SiO2/Si substrates and silica supports. Analysis using x-ray photoelectron spectroscopy showed that the surface compositions of mixed SAM-coated particles were similar to those of mixed SAMs formed on flat substrates. The critical surface tensions of the mixed SAM-coated silica particles, estimated by a developed flotation method, were similar to those of the same mixed SAMs on SiO2/Si substrates, as measured using contact angle goniometry. The performances of these mixed SAM coated-supports were examined in a HPLC system using several model proteins. The results from chromatographic experiments showed that protein retention and separation in a chromatographic column was controllable by selecting the appropriate level of column hydrophobicity and the concentration of salt in the mobile phase. Analysis of protein mass recoveries after chromatography revealed that the rate loss of protein in the column was primarily a function of the protein residence time. The described methods provide a systematic way for controlling protein retention during chromatography by tuning the hydrophobicity of the support. With proper selection, a surface hydrophobicity can be produced so that a protein can be effectively retained by a support without resulting in its permanent loss during chromatography. Advisors/Committee Members: G. Kane Jennings (committee member), M. Douglas LeVan (committee member), Scott A. Guelcher (committee member), David E. Cliffel (committee member), Paul E. Laibinis (Committee Chair).

Subjects/Keywords: self-assembled monolayers; chromatography; protein separation

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Tedjo, C. (2011). Controlling protein-surface interactions in chromatography using mixed self-assembled monolayers. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/11289

Chicago Manual of Style (16^th Edition):

Tedjo, Chrysanty. “Controlling protein-surface interactions in chromatography using mixed self-assembled monolayers.” 2011. Doctoral Dissertation, Vanderbilt University. Accessed March 05, 2021. http://hdl.handle.net/1803/11289.

MLA Handbook (7^th Edition):

Tedjo, Chrysanty. “Controlling protein-surface interactions in chromatography using mixed self-assembled monolayers.” 2011. Web. 05 Mar 2021.

Vancouver:

Tedjo C. Controlling protein-surface interactions in chromatography using mixed self-assembled monolayers. [Internet] [Doctoral dissertation]. Vanderbilt University; 2011. [cited 2021 Mar 05]. Available from: http://hdl.handle.net/1803/11289.

Council of Science Editors:

Tedjo C. Controlling protein-surface interactions in chromatography using mixed self-assembled monolayers. [Doctoral Dissertation]. Vanderbilt University; 2011. Available from: http://hdl.handle.net/1803/11289

Vanderbilt University

16. Gai, Lili. Examining the phase behavior of complex fluids with free energy methods by computer simulation.

Degree: PhD, Chemical Engineering, 2014, Vanderbilt University

URL: http://hdl.handle.net/1803/12408

► Phase transitions (i.e. transitions from one state to another) play a crucial role in most natural processes, as well as industrial operations such as evaporation.… (more)

▼ Phase transitions (i.e. transitions from one state to another) play a crucial role in most natural processes, as well as industrial operations such as evaporation. Molecular simulation has emerged as an important tool for examining phase transitions, providing a means to directly probe the transitions, in particular by means of calculating the free energy landscape. However, calculation of the free energy remains a challenge for traditional molecular dynamics (MD) or Monte Carlo (MC) approaches. This thesis focuses on the application and development of advanced sampling methods based on direct calculation of the density of states (DOS), from which thermodynamic properties such as free energy, heat capacity, and thus phase transition behavior, can be determined. First, we examine the phase transition behavior of self-assembling lipids, using the Wang-Landau (WL) MC method. We find that the WL method can provide a complete view of phase behavior of self-assembly lipids as a function of temperature, while the traditional Metropolis MC tends to miss intermediate phase transitions, providing considerable insight into self-assembly process. Next, we implement the statistical temperature MD (STMD) method, an extended version of WL sampling combined with MD movement, for massively multicore GPU architectures to enable rapid calculation of the DOS. We demonstrate near identical results to WL, fully resolving the lipid phase behavior, but at a fraction of the computational cost. With the STMD method, phase transitions of nano-confined fluids are further determined as a function of pore height and wall-fluid interactions, providing a more clear understanding of the transition from a fluid state to a non-lubricating solid phase. Finally, we present development of a novel algorithm for 2-dimensional DOS calculation, by creating a hybrid of the WL and STMD methods, verified by examination of binary Lennard-Jones fluids. This novel approach enables STMD to be used with other thermodynamic ensembles beyond the canonical ensemble via WL moves, while still retaining the efficiency of STMD and ability to examine large system sizes. Advisors/Committee Members: M. Shane Hutson (committee member), Jamey D. Young (committee member), M. Douglas LeVan (committee member), Peter T. Cummings (committee member), Clare McCabe (Committee Chair).

Subjects/Keywords: Statistical temperature molecular dynamics; Self-assembly lipids; Nano-confined fluids; Phase transition; Heat Capacity; Wang-Landau; Free energy

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Gai, L. (2014). Examining the phase behavior of complex fluids with free energy methods by computer simulation. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/12408

Chicago Manual of Style (16^th Edition):

Gai, Lili. “Examining the phase behavior of complex fluids with free energy methods by computer simulation.” 2014. Doctoral Dissertation, Vanderbilt University. Accessed March 05, 2021. http://hdl.handle.net/1803/12408.

MLA Handbook (7^th Edition):

Gai, Lili. “Examining the phase behavior of complex fluids with free energy methods by computer simulation.” 2014. Web. 05 Mar 2021.

Vancouver:

Gai L. Examining the phase behavior of complex fluids with free energy methods by computer simulation. [Internet] [Doctoral dissertation]. Vanderbilt University; 2014. [cited 2021 Mar 05]. Available from: http://hdl.handle.net/1803/12408.

Council of Science Editors:

Gai L. Examining the phase behavior of complex fluids with free energy methods by computer simulation. [Doctoral Dissertation]. Vanderbilt University; 2014. Available from: http://hdl.handle.net/1803/12408

Vanderbilt University

17. Tuberquia, Juan Carlos. Surface-initiated polymethylenation to grow superhydrophobic barrier films.

Degree: PhD, Chemical Engineering, 2011, Vanderbilt University

URL: http://hdl.handle.net/1803/12671

► The modification of surface properties has become a vital focus in materials research and is fueled by the interesting ways of tailoring composition, modifying architecture,… (more)

▼ The modification of surface properties has become a vital focus in materials research and is fueled by the interesting ways of tailoring composition, modifying architecture, and optimizing surface characteristics to impact a target application. This dissertation focuses on new approaches for the preparation and characterization of superhydrophobic (SH) surfaces. Here, we show that ultrathin films of the world’s simplest and most common polymer, polymethylene (PM) (or the chemically equivalent polyethylene), exhibit dramatically large resistances against the penetration of aqueous ions if their topology is sufficiently rough on both micro- and nano-scales to merit superhydrophobic behavior. To achieve these rough, yet thin, PM films, we have reported a new surface-initiated polymerization strategy in which immobilized borane moieties serve as active centers for the reaction with diazomethane to grow PM chains one methylene group at a time from a variety of substrates. We have explored the effect of superhydrophobicity on the dielectric properties of the film based on impedance measurements and the rationalization of such measurements using the Helmholtz theory. We have established that SH films exhibit positive deviations from the inverse capacitance predicted by the Helmholtz theory, and we have modeled the effect of the entrapped air at the PM/solution interface of SH films relative to smooth and non-superhydrophobic (NSH) films using a composite factor. Experimental results have demonstrated the remarkable sensitivity of impedance-based methods to assess the superhydrophobicity in underwater conditions. To take advantage of this potential, we have developed a strategy to identify the Cassie and the Wenzel states for underwater surfaces using impedance measurements. We have established the principles and theoretical concepts of the technique and applied it to a situation in which we explore how SH surfaces recover their initial Cassie state after transitioning into the Wenzel state and drying the liquid present in the grooves. Finally, we have discussed the extension of the SIPM approach to virtually any substrate that has incorporated olefin groups; more specifically, we have explored a strategy to grow SH films from liquid polymer substrates to introduce the concept of a SH veneer atop a NSH surface. Advisors/Committee Members: Paul E. Laibinis (committee member), Eugene LeBoeuf (committee member), M. Douglas LeVan (committee member), Peter N. Pintauro (committee member), G. Kane Jennings (Committee Chair).

Subjects/Keywords: polyethylene; EIS; impedance; superhydrophobic; surface initiated polymerization; borane; Helmholtz theory; Cassie; Wenzel

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Tuberquia, J. C. (2011). Surface-initiated polymethylenation to grow superhydrophobic barrier films. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/12671

Chicago Manual of Style (16^th Edition):

Tuberquia, Juan Carlos. “Surface-initiated polymethylenation to grow superhydrophobic barrier films.” 2011. Doctoral Dissertation, Vanderbilt University. Accessed March 05, 2021. http://hdl.handle.net/1803/12671.

MLA Handbook (7^th Edition):

Tuberquia, Juan Carlos. “Surface-initiated polymethylenation to grow superhydrophobic barrier films.” 2011. Web. 05 Mar 2021.

Vancouver:

Tuberquia JC. Surface-initiated polymethylenation to grow superhydrophobic barrier films. [Internet] [Doctoral dissertation]. Vanderbilt University; 2011. [cited 2021 Mar 05]. Available from: http://hdl.handle.net/1803/12671.

Council of Science Editors:

Tuberquia JC. Surface-initiated polymethylenation to grow superhydrophobic barrier films. [Doctoral Dissertation]. Vanderbilt University; 2011. Available from: http://hdl.handle.net/1803/12671

Vanderbilt University

18. Payne, Christina Marie. Molecular dynamics simulation of a nanoscale device for fast sequencing of DNA.

Degree: PhD, Chemical Engineering, 2007, Vanderbilt University

URL: http://hdl.handle.net/1803/14842

► We report a molecular-simulation based modeling of transport and orientation properties of single-stranded DNA molecules in a nanoscale channel as a part of a larger… (more)

Subjects/Keywords: genomic sequencing; molecular dynamics; LAMMPS; Electrophoresis; Nnanotechnology; electrode charge dynamics; Nucleotide sequence – Instruments – Design and construction; Molecular dynamics – Simulation methods; DNA; translocation; Ultramicroelectrodes – Design and construction

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Payne, C. M. (2007). Molecular dynamics simulation of a nanoscale device for fast sequencing of DNA. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/14842

Chicago Manual of Style (16^th Edition):

Payne, Christina Marie. “Molecular dynamics simulation of a nanoscale device for fast sequencing of DNA.” 2007. Doctoral Dissertation, Vanderbilt University. Accessed March 05, 2021. http://hdl.handle.net/1803/14842.

MLA Handbook (7^th Edition):

Payne, Christina Marie. “Molecular dynamics simulation of a nanoscale device for fast sequencing of DNA.” 2007. Web. 05 Mar 2021.

Vancouver:

Payne CM. Molecular dynamics simulation of a nanoscale device for fast sequencing of DNA. [Internet] [Doctoral dissertation]. Vanderbilt University; 2007. [cited 2021 Mar 05]. Available from: http://hdl.handle.net/1803/14842.

Council of Science Editors:

Payne CM. Molecular dynamics simulation of a nanoscale device for fast sequencing of DNA. [Doctoral Dissertation]. Vanderbilt University; 2007. Available from: http://hdl.handle.net/1803/14842

Vanderbilt University

19. Schindler, Bryan Joseph. Henry's Law Behavior and Density Functional Theory Analysis of Adsorption Equilibrium.

Degree: PhD, Chemical Engineering, 2008, Vanderbilt University

URL: http://hdl.handle.net/1803/13838

► This work focuses on three different aspects of adsorption equilibrium: the measurement of adsorption equilibrium into the Henry's law region for n-pentane, the calculation of… (more)

▼ This work focuses on three different aspects of adsorption equilibrium: the measurement of adsorption equilibrium into the Henry's law region for n-pentane, the calculation of the maximum isosteric heat of adsorption achievable in the Henry's law region for slit-shaped pores, and the incorporation into density functional theory of statistical associating fluid theory to treat the adsorption of chain molecules in slit-shaped pores and analyze data for nitrogen and pentane adsorbed in activated carbon. In the first section experimental data for n-pentane adsorbed on BPL activated carbon in a nitrogen environment are reported at ultra-low concentrations into the Henry's law region. We introduce two methods to prepare pre-equilibrated samples at known loadings. The samples were analyzed by a purge and trap method. Adsorption data were measured at loadings from 1.0 down to 0.0001 mol/kg and pressures of 6 down to 5*10^-10 kPa. The transition into the Henry's law region occurs over a range of loadings near 0.01 mol/kg for all temperatures. The data are compared with the DR, Langmuir, and Toth equations. We discuss how the three equations transition into the Henry's law region, and how well they describe the data. Since the DR equation does not have a proper Henry's law region, we show where this equation no longer applies. The Toth equation describes the data better than the Langmuir equation. The second section discusses the isosteric heat of adsorption in the Henry's law region calculated as a function of the width of slit-shaped pores. We determine the pore width where the isosteric heat is a maximum, which is shown to be a strong function of the solid-fluid collision diameter sigma_sf and a weak function of the solid-fluid well depth potential epsilon_sf. Thus, general results are reported for the pore size where the isosteric heat of adsorption is a maximum that apply to a wide variety of gases. We compare our values of isosteric heat with those in the Henry's law region determined from adsorption data for nitrogen, argon, carbon dioxide, and methane on various activated carbons. The isosteric heats of adsorption for helium and hydrogen in carbon slit pores are also calculated, but are not compared with experimental data. Reasons for differences between the theoretical maximum and the experimental values are discussed. In the third section density functional theory is modified to include the statistical associating fluid theory equation of state in order to describe chain fluids. First-order non-mean field and second-order perturbation attractive terms are included in the model. The interaction parameters for both nitrogen and n-pentane with a carbon parallel slit pore are determined. The monolayer transition, pore condensation, and a clear freezing transition are observed for nitrogen. The effects of the pore size on when the transitions occur is discussed. The pore size distribution for BPL activated carbon is calculated from an experimental nitrogen isotherm and the model. The monolayer… Advisors/Committee Members: Eugene J. LeBoeuf (committee member), G. Kane Jennings (committee member), Kenneth A. Debelak (committee member), M. Douglas LeVan (Committee Chair), Peter T. Cummings (Committee Chair).

Subjects/Keywords: isosteric heat of adsorption; Adsorption; Henry's law; density functional theory; Density functionals; Volatile organic compounds – Absorption and adsorption; Chemical equilibrium

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Schindler, B. J. (2008). Henry's Law Behavior and Density Functional Theory Analysis of Adsorption Equilibrium. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/13838

Chicago Manual of Style (16^th Edition):

Schindler, Bryan Joseph. “Henry's Law Behavior and Density Functional Theory Analysis of Adsorption Equilibrium.” 2008. Doctoral Dissertation, Vanderbilt University. Accessed March 05, 2021. http://hdl.handle.net/1803/13838.

MLA Handbook (7^th Edition):

Schindler, Bryan Joseph. “Henry's Law Behavior and Density Functional Theory Analysis of Adsorption Equilibrium.” 2008. Web. 05 Mar 2021.

Vancouver:

Schindler BJ. Henry's Law Behavior and Density Functional Theory Analysis of Adsorption Equilibrium. [Internet] [Doctoral dissertation]. Vanderbilt University; 2008. [cited 2021 Mar 05]. Available from: http://hdl.handle.net/1803/13838.

Council of Science Editors:

Schindler BJ. Henry's Law Behavior and Density Functional Theory Analysis of Adsorption Equilibrium. [Doctoral Dissertation]. Vanderbilt University; 2008. Available from: http://hdl.handle.net/1803/13838

Vanderbilt University

20. Glover, Thomas Grant. Novel Adsorbent Synthesis, Diffusion in Nanoporous Materials, and Adsorption System Optimization.

Degree: PhD, Chemical Engineering, 2008, Vanderbilt University

URL: http://hdl.handle.net/1803/11574

► This research focuses three specific topics related to gas-phase adsorption: the synthesis and characterization of a novel carbon-silica composite adsorbent material, the diffusion of condensable… (more)

▼ This research focuses three specific topics related to gas-phase adsorption: the synthesis and characterization of a novel carbon-silica composite adsorbent material, the diffusion of condensable vapors in single adsorbent particles, and an examination of pulse inputs and layered-bed optimization. The first segment of the work details the synthesis of a carbon-silica composite (CSC) adsorbent derived from MCM-41 and polyfurfuryl alcohol. The novel material has a high surface area, and a narrow pore size distribution. Materials were also prepared using different furfuryl alcohol solvents and were polymerized and carbonized at different pressures. The surface area of the materials is affected by both solvent selection and the pressure at which carbonization takes place. The novel material is unique because the carbon pores are created from templating rather than from an activation process. The next segment extends a concentration-swing frequency response method to examine mass transfer rates and concentration dependence for adsorption of condensable vapors in adsorbent particles. The adsorption kinetics of water and hexane in BPL activated carbon and the adsorption of water in silica gel are determined at several different concentrations. The mechanism that best describes the adsorption of water in BPL activated carbon is nanopore diffusion, and both models can be used to describe the diffusion of hexane in BPL activated carbon. The diffusion of water in silica gel is best characterized by the Glueckauf linear driving force model. In the final segment of this work a mathematical model is developed to examine the sensitivity of fixed beds with respect to system parameters. The impact of mass and energy transfer effects and adsorbent layer thicknesses are determined by calculating the derivatives of the outlet concentration and outlet temperature. The adsorption of hexane on BPL activated carbon is contrasted with the adsorption of nitrogen on carbon molecular sieve, and combined mass and energy effects are considered by studying the adsorption of nitrogen on BPL activated carbon. The sensitivity data are then applied to determine the optimum bed layering of a two-layer, two-bed PSA system. Advisors/Committee Members: Eugene J. LeBoeuf (committee member), G. Kane Jennings (committee member), Kenneth A. Debelak (committee member), Scott A. Guelcher (committee member), M. Douglas LeVan (Committee Chair).

Subjects/Keywords: mass transfer; furfuryl alcohol; carbon; layered bed; optimization; MCM-41; frequency response; vapors; diffusion; adsorption; Gases – Absorption and adsorption; Carbon composites; Porous materials

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Glover, T. G. (2008). Novel Adsorbent Synthesis, Diffusion in Nanoporous Materials, and Adsorption System Optimization. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/11574

Chicago Manual of Style (16^th Edition):

Glover, Thomas Grant. “Novel Adsorbent Synthesis, Diffusion in Nanoporous Materials, and Adsorption System Optimization.” 2008. Doctoral Dissertation, Vanderbilt University. Accessed March 05, 2021. http://hdl.handle.net/1803/11574.

MLA Handbook (7^th Edition):

Glover, Thomas Grant. “Novel Adsorbent Synthesis, Diffusion in Nanoporous Materials, and Adsorption System Optimization.” 2008. Web. 05 Mar 2021.

Vancouver:

Glover TG. Novel Adsorbent Synthesis, Diffusion in Nanoporous Materials, and Adsorption System Optimization. [Internet] [Doctoral dissertation]. Vanderbilt University; 2008. [cited 2021 Mar 05]. Available from: http://hdl.handle.net/1803/11574.

Council of Science Editors:

Glover TG. Novel Adsorbent Synthesis, Diffusion in Nanoporous Materials, and Adsorption System Optimization. [Doctoral Dissertation]. Vanderbilt University; 2008. Available from: http://hdl.handle.net/1803/11574

Vanderbilt University

21. Rutherford, Mark Leland. The theory, development, and implementation of partitioned error control.

Degree: PhD, Chemical Engineering, 2006, Vanderbilt University

URL: http://hdl.handle.net/1803/11023

► THE THEORY, DEVELOPMENT, AND IMPLEMENTATION OF PARTITIONED ERROR CONTROL Mark Leland Rutherford Dissertation under the direction of Professor Kenneth A. Debelak Partitioned Error Control (PEC)… (more)

Subjects/Keywords: Control theory; H-infinity; two-degree-of-freedom; Inverse Model Prefilter; Partitioned Error Control; Internal Model Control; Chemical process control

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Rutherford, M. L. (2006). The theory, development, and implementation of partitioned error control. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/11023

Chicago Manual of Style (16^th Edition):

Rutherford, Mark Leland. “The theory, development, and implementation of partitioned error control.” 2006. Doctoral Dissertation, Vanderbilt University. Accessed March 05, 2021. http://hdl.handle.net/1803/11023.

MLA Handbook (7^th Edition):

Rutherford, Mark Leland. “The theory, development, and implementation of partitioned error control.” 2006. Web. 05 Mar 2021.

Vancouver:

Rutherford ML. The theory, development, and implementation of partitioned error control. [Internet] [Doctoral dissertation]. Vanderbilt University; 2006. [cited 2021 Mar 05]. Available from: http://hdl.handle.net/1803/11023.

Council of Science Editors:

Rutherford ML. The theory, development, and implementation of partitioned error control. [Doctoral Dissertation]. Vanderbilt University; 2006. Available from: http://hdl.handle.net/1803/11023

Vanderbilt University

22. Koparde, Vishal Nitinchandra. Study of Titanium Dioxide Nanoparticles via Molecular Dynamics Simulations.

Degree: PhD, Chemical Engineering, 2006, Vanderbilt University

URL: http://hdl.handle.net/1803/13598

► Molecular dynamics simulations are used to study various aspects of nanoparticles of anatase and rutile, which are the two most abundant polymorphs of titanium dioxide… (more)

Subjects/Keywords: phase transformation; anatase; Titanium dioxide; Nanoparticles – Analysis; rutile; nanoparticles; Sintering; Molecular dynamics

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Koparde, V. N. (2006). Study of Titanium Dioxide Nanoparticles via Molecular Dynamics Simulations. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/13598

Chicago Manual of Style (16^th Edition):

Koparde, Vishal Nitinchandra. “Study of Titanium Dioxide Nanoparticles via Molecular Dynamics Simulations.” 2006. Doctoral Dissertation, Vanderbilt University. Accessed March 05, 2021. http://hdl.handle.net/1803/13598.

MLA Handbook (7^th Edition):

Koparde, Vishal Nitinchandra. “Study of Titanium Dioxide Nanoparticles via Molecular Dynamics Simulations.” 2006. Web. 05 Mar 2021.

Vancouver:

Koparde VN. Study of Titanium Dioxide Nanoparticles via Molecular Dynamics Simulations. [Internet] [Doctoral dissertation]. Vanderbilt University; 2006. [cited 2021 Mar 05]. Available from: http://hdl.handle.net/1803/13598.

Council of Science Editors:

Koparde VN. Study of Titanium Dioxide Nanoparticles via Molecular Dynamics Simulations. [Doctoral Dissertation]. Vanderbilt University; 2006. Available from: http://hdl.handle.net/1803/13598

Vanderbilt University

23. Dumas, Jerald. Allograft mineralized bone particle/polyurethane composites for bone tissue engineering.

Degree: PhD, Chemical Engineering, 2010, Vanderbilt University

URL: http://hdl.handle.net/1803/15273

► Healing of bone defects such as open fractures is a challenging clinical problem. An ideal treatment for bone defects would restore both form and function… (more)

▼ Healing of bone defects such as open fractures is a challenging clinical problem. An ideal treatment for bone defects would restore both form and function of the tissue. In this research, a two-component allograft bone particle/polyurethane system that can be compression molded or injected to treat bone defects has been developed. This biodegradable polyurethane (PUR) consists of lysine triisocyanate (LTI), polyester polyol, triethyldiamine (TEDA) catalyst, and allograft mineralized bone particles (AMBP). AMBP, which is bound to the PUR phase, is used as a filler to enhance mechanical properties and provide a resorbable pathway for cellular infiltration. Furthermore, pores can be incorporated in this system with the addition of water that reacts with isocyante groups, yielding carbon dioxide which functions as a blowing agent. For weight-bearing implant applications, non-porous composites have been fabricated by reactive compression molding. At volume fractions exceeding the random close-packing (RCP) limit, the particulated allograft component presented a nearly continuous osteoconductive pathway for cells. Furthermore, an injectable AMBP/PUR composite has been developed as a bone void filler (BVF) with tunable properties that supports rapid cellular infiltration and remodeling. The materials incorporate particulated allograft bone particles and have variable (e.g., 30 - 70%) porosities. When injected in femoral plug defects in athymic rats, the composites supported extensive cellular infiltration, allograft resorption, and new bone formation at three weeks. As a drug delivery system, recombinant human morphogenetic protein (rhBMP-2) was added prior to injection of the AMBP/PUR BVF. AMBP/PUR BVF with the incorporation of rhBMP-2 showed substantial new bone formation in a 15 mm NZW rabbit calvaria critical-size defect. Finally, an injectable AMBP/PUR putty (< 5% porosity) with the incorporation of rhBMP-2 was synthesized and studied in the rabbit distal femur model. Substantial bone remodeling was observed at rhBMP-2 levels less than standard dose, suggesting an efficient release of rhBMP-2. Results from this research suggest that both the AMBP/PUR composites are a promising, versatile biomaterial for bone regeneration in orthopaedic and craniofacial applications. Advisors/Committee Members: Todd Boyce (committee member), Ginger Holt (committee member), M. Douglas LeVan (committee member), Peter Cummings (committee member), G. Kane Jennings (committee member), Scott Guelcher (Committee Chair).

Subjects/Keywords: polyurethane; composite; allograft; bone; tissue engineering

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Dumas, J. (2010). Allograft mineralized bone particle/polyurethane composites for bone tissue engineering. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/15273

Chicago Manual of Style (16^th Edition):

Dumas, Jerald. “Allograft mineralized bone particle/polyurethane composites for bone tissue engineering.” 2010. Doctoral Dissertation, Vanderbilt University. Accessed March 05, 2021. http://hdl.handle.net/1803/15273.

MLA Handbook (7^th Edition):

Dumas, Jerald. “Allograft mineralized bone particle/polyurethane composites for bone tissue engineering.” 2010. Web. 05 Mar 2021.

Vancouver:

Dumas J. Allograft mineralized bone particle/polyurethane composites for bone tissue engineering. [Internet] [Doctoral dissertation]. Vanderbilt University; 2010. [cited 2021 Mar 05]. Available from: http://hdl.handle.net/1803/15273.

Council of Science Editors:

Dumas J. Allograft mineralized bone particle/polyurethane composites for bone tissue engineering. [Doctoral Dissertation]. Vanderbilt University; 2010. Available from: http://hdl.handle.net/1803/15273

Vanderbilt University

24. Lu, Jin. Improving the representation of multicomponent aerosols in numerical models.

Degree: PhD, Chemical Engineering, 2005, Vanderbilt University

URL: http://hdl.handle.net/1803/14995

► This thesis is motivated by the need to improve performance of aerosol simulation in air quality models. I investigate the relationship between multicomponent aerosol sectional… (more)

Subjects/Keywords: numerical model; aerosol distribution conversion; secondary organic aerosol partitioning; multicomponent aerosol; externally mixed aerosol particles; Atmospheric aerosols – Mathematical models; Air quality – Mathematical models

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Lu, J. (2005). Improving the representation of multicomponent aerosols in numerical models. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/14995

Chicago Manual of Style (16^th Edition):

Lu, Jin. “Improving the representation of multicomponent aerosols in numerical models.” 2005. Doctoral Dissertation, Vanderbilt University. Accessed March 05, 2021. http://hdl.handle.net/1803/14995.

MLA Handbook (7^th Edition):

Lu, Jin. “Improving the representation of multicomponent aerosols in numerical models.” 2005. Web. 05 Mar 2021.

Vancouver:

Lu J. Improving the representation of multicomponent aerosols in numerical models. [Internet] [Doctoral dissertation]. Vanderbilt University; 2005. [cited 2021 Mar 05]. Available from: http://hdl.handle.net/1803/14995.

Council of Science Editors:

Lu J. Improving the representation of multicomponent aerosols in numerical models. [Doctoral Dissertation]. Vanderbilt University; 2005. Available from: http://hdl.handle.net/1803/14995

Vanderbilt University

25. Redmill, Patrick Scott. Probing the solubility of selected nanoscale building blocks using molecular simulation.

Degree: PhD, Chemical Engineering, 2008, Vanderbilt University

URL: http://hdl.handle.net/1803/15298

► CHEMICAL ENGINEERING PROBING THE SOLUBILITY OF SELECTED NANOSCALE BUILDING BLOCKS USING MOLECULAR SIMULATION Patrick Scott Redmill under the supervision of Peter T. Cummings and Clare… (more)

▼ CHEMICAL ENGINEERING PROBING THE SOLUBILITY OF SELECTED NANOSCALE BUILDING BLOCKS USING MOLECULAR SIMULATION Patrick Scott Redmill under the supervision of Peter T. Cummings and Clare McCabe The solubility of a variety of nanoscale building blocks (C60, carbon nanotubes, and polyhedral oligomeric silsesquioxanes and their functionalized derivatives) have been determined using computational techniques. In particular, the Gibbs free energy of solvation () for fullerene particles of differing size and shape has been determined in octanol and water solvents using molecular dynamics simulations and thermodynamic integration. The fullerene molecules are all found to be strongly hydrophobic and organophilic, suggesting a strong preference for the organic phase. From a comparison of results for capped and uncapped carbon nanotubes we found that uncapped tubes exhibit significantly higher hydrophobicity than capped tubes. The use of the UNIFAC group-contribution method to predict infinite dilution activity coefficients () for selected nanoparticles in aqueous and organic solvents has also been evaluated. Ab initio calculations have been performed to determine the required binary energy parameters not available in the UNIFAC database. We find that UNIFAC can satisfactorily estimate the ratio of the activity coefficient of the particle in water versus the activity coefficient of the particle in octanol, which allows for estimation of the octanol-water partition coefficient (). Additionally, to gauge the propensity of the nanoparticles to cross a heterogeneous membrane, the Gibbs free energy of transfer () for each particle has been determined using molecular dynamics simulations and potential of mean force calculations performed across the axis normal to the bilayer surface. The studies show that C60 has a substantial energetic preference for the polar head region of the lipid bilayer system, whereas the POSS molecules studied show indicate an affinity for the water phase. Advisors/Committee Members: Eugene LeBoeuf (committee member), Scott Guelcher (committee member), M. Douglas LeVan (committee member), Clare McCabe (Committee Chair), Peter T. Cummings (Committee Chair).

Subjects/Keywords: Octyl alcohol; Organosilicon compounds; molecular simulation; Nanoparticles – Solubility; Gibbs free energy; octanol-water partition coefficient; Molecular dynamics – Computer simulation; Nanoparticles – Toxicology

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Redmill, P. S. (2008). Probing the solubility of selected nanoscale building blocks using molecular simulation. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/15298

Chicago Manual of Style (16^th Edition):

Redmill, Patrick Scott. “Probing the solubility of selected nanoscale building blocks using molecular simulation.” 2008. Doctoral Dissertation, Vanderbilt University. Accessed March 05, 2021. http://hdl.handle.net/1803/15298.

MLA Handbook (7^th Edition):

Redmill, Patrick Scott. “Probing the solubility of selected nanoscale building blocks using molecular simulation.” 2008. Web. 05 Mar 2021.

Vancouver:

Redmill PS. Probing the solubility of selected nanoscale building blocks using molecular simulation. [Internet] [Doctoral dissertation]. Vanderbilt University; 2008. [cited 2021 Mar 05]. Available from: http://hdl.handle.net/1803/15298.

Council of Science Editors:

Redmill PS. Probing the solubility of selected nanoscale building blocks using molecular simulation. [Doctoral Dissertation]. Vanderbilt University; 2008. Available from: http://hdl.handle.net/1803/15298

Vanderbilt University

26. Hafeman, Andrea Elise. Polyurethane scaffold with delivery of biologically active small molecules for tissue regeneration.

Degree: PhD, Chemical Engineering, 2010, Vanderbilt University

URL: http://hdl.handle.net/1803/11703

► Limited availability of autograft tissue for bone and skin wound healing has established the demand for improved synthetic biomaterials. Biodegradable polyurethane (PUR) scaffolds exhibit favorable… (more)

▼ Limited availability of autograft tissue for bone and skin wound healing has established the demand for improved synthetic biomaterials. Biodegradable polyurethane (PUR) scaffolds exhibit favorable properties for wound healing applications, as they support cellular proliferation and new tissue formation both in vitro and in vivo. This work describes the design and development of PUR scaffolds with polyester triols and aliphatic triisocyanates. The scaffolds, with up to 93% porosity, were evaluated based on physical, thermal, mechanical, and biological properties; these properties could be adjusted by variations in PUR scaffold composition. Furthermore, the scaffolds were formulated for injectable application, which allows for customizable and minimally invasive procedures. PUR scaffolds degrade by hydrolysis in vitro, but faster degradation in vivo implicates cell-mediated degradation, specifically by macrophages along the material surfaces. Indeed, PUR degradation was accelerated in vitro when the scaffolds were incubated in enzymatic or oxidative media. In particular, reactive oxygen intermediates had a significant effect on degradation, presumably causing chain scission in both the hard and soft segments of the PUR. Biologically active molecules, such as antibiotics, small molecule drugs, and growth factors, were incorporated into the foams during synthesis for local, controlled release to enhance wound repair. Local antibiotic delivery could help in healing infected wounds, especially bone fractures, as the scaffold and antibiotic delivery system could be administered in one procedure. This would preclude the need to first implant antibiotic-loaded cement beads, followed by additional surgeries to remove the beads and implant a bone graft. Lovastatin is known to stimulate osteogenesis, and so it was also examined as a potential additive for local release. Scaffolds containing lovastatin enhanced new bone formation both in vitro and in vivo within the defect area. Due to their injectability, biocompatibility, tunable degradation, and potential for release of biologically active small molecules, these PUR scaffolds are potentially promising therapies for tissue engineering. Advisors/Committee Members: G. Kane Jennings (committee member), Jeffrey M. Davidson (committee member), M. Douglas LeVan (committee member), Paul E. Laibinis (committee member), Scott A. Guelcher (Committee Chair).

Subjects/Keywords: skin wound healing; bone fracture repair; tissue engineering; mechanical properties; controlled release; elastomeric; biodegradable; porous; injectable; lovastatin; antibiotic

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Hafeman, A. E. (2010). Polyurethane scaffold with delivery of biologically active small molecules for tissue regeneration. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/11703

Chicago Manual of Style (16^th Edition):

Hafeman, Andrea Elise. “Polyurethane scaffold with delivery of biologically active small molecules for tissue regeneration.” 2010. Doctoral Dissertation, Vanderbilt University. Accessed March 05, 2021. http://hdl.handle.net/1803/11703.

MLA Handbook (7^th Edition):

Hafeman, Andrea Elise. “Polyurethane scaffold with delivery of biologically active small molecules for tissue regeneration.” 2010. Web. 05 Mar 2021.

Vancouver:

Hafeman AE. Polyurethane scaffold with delivery of biologically active small molecules for tissue regeneration. [Internet] [Doctoral dissertation]. Vanderbilt University; 2010. [cited 2021 Mar 05]. Available from: http://hdl.handle.net/1803/11703.

Council of Science Editors:

Hafeman AE. Polyurethane scaffold with delivery of biologically active small molecules for tissue regeneration. [Doctoral Dissertation]. Vanderbilt University; 2010. Available from: http://hdl.handle.net/1803/11703

Vanderbilt University

27. Bai, Dongshun. Surface-catalyzed growth of pH-responsive copolymer thin films.

Degree: PhD, Chemical Engineering, 2007, Vanderbilt University

URL: http://hdl.handle.net/1803/11569

► Polymer films that respond to pH have broad applications in chemical and biological sensors, smart membranes, and dynamic surfaces. We have engineered a new class… (more)

▼ Polymer films that respond to pH have broad applications in chemical and biological sensors, smart membranes, and dynamic surfaces. We have engineered a new class of pH-responsive copolymer films on gold electrode surfaces by first developing a controlled, surface-catalyzed copolymerization to prepare a copolymer film consistent with poly(methylene-co-ethyl acetate) and subsequently hydrolyzing the ester side chains to carboxylic acids (denoted as PM-CO2H). The effects of polymer composition and thickness on pH response were investigated by electrochemical impedance spectroscopy, reflectance-absorption infrared spectroscopy, and spectroscopic ellipsometry. At a 1% - 4% molar acid content, the copolymer film exhibits a five order of magnitude change in its resistance to ion transport over 2 – 3 pH units. The onset pH at which this response initiates can be tailored from pH 5 to 10 by decreasing the acid content in the film from 4% to 1%. All films exhibit rapid ionization but gradual protonation. The increase of acid content within the films accelerates both processes, especially the protonation process. At the same acid content, thinner films require much less time to protonate, consistent with a diffusion-limited process, although film thickness in the sub-100 nm regime has no measurable effect on the rates of ionization. Thus, based on acid content and thickness, the range and rate of the pH-induced response can be tailored. These films are particularly interesting for pH-dependent separations and as chemically sensitive thin films. For separations, these super-responsive films can be grown as ultrathin skins on nanoporous membranes to control the passage of ions in a pH-specific manner. To provide sensitivity over a broader range of pH for sensor applications, the acid groups can be further modified to create tertiary amino side groups that become protonated and charged as pH is reduced, opposite to the response of PM-CO2H. Advisors/Committee Members: Piotr Kaszynski (committee member), Peter T. Cummings (committee member), Bridget R. Rogers (committee member), M. Douglas LeVan (committee member), G. Kane Jennings (Committee Chair).

Subjects/Keywords: Copolymers – Design and construction; thin films; surface-catalyzed; pH-responsive; polymer

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Bai, D. (2007). Surface-catalyzed growth of pH-responsive copolymer thin films. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/11569

Chicago Manual of Style (16^th Edition):

Bai, Dongshun. “Surface-catalyzed growth of pH-responsive copolymer thin films.” 2007. Doctoral Dissertation, Vanderbilt University. Accessed March 05, 2021. http://hdl.handle.net/1803/11569.

MLA Handbook (7^th Edition):

Bai, Dongshun. “Surface-catalyzed growth of pH-responsive copolymer thin films.” 2007. Web. 05 Mar 2021.

Vancouver:

Bai D. Surface-catalyzed growth of pH-responsive copolymer thin films. [Internet] [Doctoral dissertation]. Vanderbilt University; 2007. [cited 2021 Mar 05]. Available from: http://hdl.handle.net/1803/11569.

Council of Science Editors:

Bai D. Surface-catalyzed growth of pH-responsive copolymer thin films. [Doctoral Dissertation]. Vanderbilt University; 2007. Available from: http://hdl.handle.net/1803/11569

Vanderbilt University

28. Moate, Joseph R. Temperature swing adsorption compression and membrane separations.

Degree: PhD, Chemical Engineering, 2009, Vanderbilt University

URL: http://hdl.handle.net/1803/14033

► CHEMICAL AND BIOMOLECULAR ENGINEERING TEMPERATURE SWING ADSORPTION COMPRESSION AND MEMBRANE SEPARATIONS JOSEPH R. MOATE Dissertation under the direction of Professor M. Douglas LeVan The feasibility… (more)

▼ CHEMICAL AND BIOMOLECULAR ENGINEERING TEMPERATURE SWING ADSORPTION COMPRESSION AND MEMBRANE SEPARATIONS JOSEPH R. MOATE Dissertation under the direction of Professor M. Douglas LeVan The feasibility of the capture and pressurization of CO2 from an enclosed environment using an integrated membrane dryer and two-stage temperature swing adsorption compression system is investigated in this work by fundamental research on the operation of temperature swing adsorption (TSA) beds, dispersive flow through packed beds, and dehydration of a process stream using a shell and tube membrane module. The first section of this dissertation focuses on sizing a two-stage TSA compressor that preferentially adsorbs CO2 and analysis of its subsequent performance with the aid of mathematical models. Solutions to the material and energy balances reveal a relationship between the volume of the two stages and the pressures reached within the stages. Also, the method in which the beds are heated, whether uniform or not, is investigated and is found to have a significant impact on the desorption of CO2. Next, a mathematical model that describes nonplug flow through a packed bed of adsorbent in which a constant pattern develops is studied for a slightly favorable isotherm. A generalized perturbation solution of the model that extends to the first and second order is developed that considers both axial and transverse gradients of concentration in the fluid phase. First order corrections to the plug flow model and fluid-phase concentration profiles for two example velocity profiles are formulated that illustrate the influence of the shape of the velocity profile on breakthrough behavior. In the final section, the effects of scale on the dehydration of a process stream is considered for two shell and tube membrane modules, one with a vacuum on the shell side and the other with a purge gas to facilitate water transport. It was determined that special considerations must be made to prevent flow maldistribution within the shell side of the membrane modules as this degrades dehydration performance. Also, the use of a vacuum on the shell side successfully dehydrates a process stream, but water transport through the membrane is overestimated using previously developed relationships for the diffusion coefficient. Approved: Date: Advisors/Committee Members: Greg Walker (committee member), G. Kane Jennings (committee member), Kenneth Debelak (committee member), Bridget Rogers (committee member), M. Douglas LeVan (Committee Chair).

Subjects/Keywords: zeolite; Nafion

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Moate, J. R. (2009). Temperature swing adsorption compression and membrane separations. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/14033

Chicago Manual of Style (16^th Edition):

Moate, Joseph R. “Temperature swing adsorption compression and membrane separations.” 2009. Doctoral Dissertation, Vanderbilt University. Accessed March 05, 2021. http://hdl.handle.net/1803/14033.

MLA Handbook (7^th Edition):

Moate, Joseph R. “Temperature swing adsorption compression and membrane separations.” 2009. Web. 05 Mar 2021.

Vancouver:

Moate JR. Temperature swing adsorption compression and membrane separations. [Internet] [Doctoral dissertation]. Vanderbilt University; 2009. [cited 2021 Mar 05]. Available from: http://hdl.handle.net/1803/14033.

Council of Science Editors:

Moate JR. Temperature swing adsorption compression and membrane separations. [Doctoral Dissertation]. Vanderbilt University; 2009. Available from: http://hdl.handle.net/1803/14033

Vanderbilt University

29. Cetin, Barbaros. Microfluidic Continuous Separation of Particles and Cells by using AC-Dielectrophoresis.

Degree: PhD, Mechanical Engineering, 2009, Vanderbilt University

URL: http://hdl.handle.net/1803/13642

► AC-dielelectrophoresis is utilized inside a lab-on-a-chip device to separate particles and cells. Dielectrophoresis is the movement of particles in a non-uniform electric field due to… (more)

▼ AC-dielelectrophoresis is utilized inside a lab-on-a-chip device to separate particles and cells. Dielectrophoresis is the movement of particles in a non-uniform electric field due to the interaction of the particle's dipole and spatial gradient of the electric field. Dielectrophoresis is a subtle solution to manipulate particles and cells at microscale due to its favorable scaling for reduced size of the system. Dielectrophoresis is applicable with both DC and AC fields. DC-dielectrophoresis only depends on the electrical conductivities of the particle and the medium. AC-dielectrohoresis depends on the permittivities of the particle and the medium, and the field frequency. AC-dielectrophoresis is richer in the sense that both positive and negative dielectrophoretic force can be generated for biological particles by tuning the field frequency. The dielectrophoretic force depends on the size and the electrical properties of the particles and the suspending medium which makes the separation of particles and cells based on their size and based on their electrical properties possible. In this dissertation, the continuous separation of particles and cells based on their size and based on their electrical properties is achieved inside a lab-on-a-chip device. PDMS (polydimethylsiloxane) microchannels are fabricated using soft lithography technique. The flow is induced by pressure gradient. Simple, 3D electrodes which are fabricated by a simple and inexpensive technique extended from soft-lithographic fabrication are used to achieve a localized, non-uniform electric field. Dielectrophoretic force is generated in the transverse direction to the flow by inserting 3D electrodes along the channel side walls. The localized electric field is important to reduce the Joule heating and any adverse effects on biological particles due to the interaction of particles with the electric field. Latex particles of different size and mixture of white blood cells (which have a typical size of 8-12 micron) and yeast cells (which have a typical size of 3-5 micron) is separated based on their size difference. The separation based on electrical properties is demonstrated by means of the separation of 10 micron latex particles and white blood cells. A numerical simulation based on Lagrangian tracking method is used to simulate the particle trajectories. The present designs have the feature of using simple electrodes like DC-dielectrohoretic devices and of using low electrical potential like AC-dielectrophoretic devices; they are unique in a sense that the effect of the electric field is confined in a small area which means a very short time for the interaction of the particles with the electric field. Advisors/Committee Members: Dr. Haoxiang Luo (committee member), Dr. Deyu Li (committee member), Dr. M. Douglas LeVan (committee member), Dr. Robert W. Pitz (committee member), Dr. Dongqing Li (Committee Chair).

Subjects/Keywords: dielectrophoresis; separation of particles and cells; Microfluidics; lab-on-a-chip

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Cetin, B. (2009). Microfluidic Continuous Separation of Particles and Cells by using AC-Dielectrophoresis. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/13642

Chicago Manual of Style (16^th Edition):

Cetin, Barbaros. “Microfluidic Continuous Separation of Particles and Cells by using AC-Dielectrophoresis.” 2009. Doctoral Dissertation, Vanderbilt University. Accessed March 05, 2021. http://hdl.handle.net/1803/13642.

MLA Handbook (7^th Edition):

Cetin, Barbaros. “Microfluidic Continuous Separation of Particles and Cells by using AC-Dielectrophoresis.” 2009. Web. 05 Mar 2021.

Vancouver:

Cetin B. Microfluidic Continuous Separation of Particles and Cells by using AC-Dielectrophoresis. [Internet] [Doctoral dissertation]. Vanderbilt University; 2009. [cited 2021 Mar 05]. Available from: http://hdl.handle.net/1803/13642.

Council of Science Editors:

Cetin B. Microfluidic Continuous Separation of Particles and Cells by using AC-Dielectrophoresis. [Doctoral Dissertation]. Vanderbilt University; 2009. Available from: http://hdl.handle.net/1803/13642

Vanderbilt University

30. Dyer, Peter James. Molecular modeling of aqueous solutions: The effects of molecular polarization on classical forcefield development.

Degree: PhD, Chemical Engineering, 2008, Vanderbilt University

URL: http://hdl.handle.net/1803/14394

► The effect of polarization and its importance to the correct reproduction of the behavior of aqueous solutions is presented. First, the effect of the addition… (more)

▼ The effect of polarization and its importance to the correct reproduction of the behavior of aqueous solutions is presented. First, the effect of the addition of polarization on non-polar solutes in both pure water and aqueous solutions containing electrolytes was studied. For pure water, the use of polarizable solutes leads to improved quantative agreement with experimental measurements. For aqueous solutions containing electrolytes, the inclusion of polarizability increases the solubility of the solute, but is not able to reproduce salting-out effects as a function of ion concentration. It has been found that the salting-out effects, are not due to increasing ordering of the bulk water in the system, but rather due to the use of an overly repulsive ion-solute interaction potential. A classical water model, which features Gaussian charges and polarizability (GCPM), was compared with Car-Parrinello simulations (CPMD), compares the mean and the distribution of the total dipole moment. It was found that GCPM obtained a total dipole moments bound between the values obtained using two popular methods from CPMD. The effect of using a Gaussian distribution in the modeling of the electrostatic interaction of simple ions with polarization in aqueous solutions was studied. It has been shown that kosmotropic ions undergo bulk solvation, while the chaotropic ions undergo surface solvation. Good agreement with ab initio simulations for the induced dipole moment was also obtained. GCPM still shows the same trends as other classical models for water in relation to the ion-water orientation, but it shows a reduced attachment of the surrounding water molecules, indicated by the lower residence times in the first hydration shell. We have constructed a group of classical potentials based on ab initio density functional theory calculations to describe the chemical bonding between the benzenedithiolate molecule and gold clusters. It was found that the forcefield parameters depend on cluster size and geometry, but variations of these have a minimal impact on the global packing structure of BDT self-assembled monolayer on the Au (111) surface. Advisors/Committee Members: Kenneth A. Debelak (committee member), M. Douglas LeVan (committee member), Jens Meiler (committee member), Clare McCabe (committee member), Peter T. Cummings (Committee Chair).

Subjects/Keywords: forcefield development; Aqueous solutions; polarization; molecular modeling

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Dyer, P. J. (2008). Molecular modeling of aqueous solutions: The effects of molecular polarization on classical forcefield development. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/14394

Chicago Manual of Style (16^th Edition):

Dyer, Peter James. “Molecular modeling of aqueous solutions: The effects of molecular polarization on classical forcefield development.” 2008. Doctoral Dissertation, Vanderbilt University. Accessed March 05, 2021. http://hdl.handle.net/1803/14394.

MLA Handbook (7^th Edition):

Dyer, Peter James. “Molecular modeling of aqueous solutions: The effects of molecular polarization on classical forcefield development.” 2008. Web. 05 Mar 2021.

Vancouver:

Dyer PJ. Molecular modeling of aqueous solutions: The effects of molecular polarization on classical forcefield development. [Internet] [Doctoral dissertation]. Vanderbilt University; 2008. [cited 2021 Mar 05]. Available from: http://hdl.handle.net/1803/14394.

Council of Science Editors:

Dyer PJ. Molecular modeling of aqueous solutions: The effects of molecular polarization on classical forcefield development. [Doctoral Dissertation]. Vanderbilt University; 2008. Available from: http://hdl.handle.net/1803/14394

		in
And / Or
		in
And / Or
		in
And / Or
		in

Open Access Theses and Dissertations