You searched for +publisher:"Georgia Tech" +contributor:("Koros, William").
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Georgia Tech
1.
Chen, Grace.
Fiber adsorbents for tert-butyl mercaptan removal from pipeline grade natural gas.
Degree: MS, Chemical and Biomolecular Engineering, 2013, Georgia Tech
URL: http://hdl.handle.net/1853/52912 
► The purpose of this thesis study is to assess the feasibility of using a fiber sorbent module system to remove t-butyl mercaptan (TBM), a common…
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▼ The purpose of this thesis study is to assess the feasibility of using a fiber sorbent module system to remove t-butyl mercaptan (TBM), a common odorant, from pipeline grade natural gas. Odorants such as mercaptans are added to natural gas for safety reasons, but their combustion products are corrosive and decrease the lifetime of the turbines in which they are combusted. Therefore, it is desirable to remove the odorants to extend this lifetime.
A TBM removal system attached to a 840 MW natural gas-fueled combined cycle power plant unit such as the one at Plant McDonough-Atkinson (Smyrna, GA) must process gas at a flow rate of approximately 180,000 standard cubic feet per minute. A single 85 MW GE 7EAQ gas turbine has a flow rate of approximately 15,000 standard cubic feet per minute, and will serve as the basis for a system design and process analysis study. The concentration of odorants in natural gas is typically 10 ppm or less. For the purposes of this study, the upper limit of 10 ppm TBM will be used. Zeolite 13X was selected as the model adsorbent for this study due to its high sorption capacity for mercaptans and its ease of incorporation into both fibers and pellets.
Design calculations were performed to optimize and determine the feasibility of fiber modules for TBM removal, as well as assess their advantages over conventional pellet packed beds. An understanding of how critical parameters such as heat and mass transfer resistances, pressure drop, and capital and operating costs are affected by design specifications such as sorbent and bed dimensions, allows an optimal design for the needs of the model turbine to be found. Based on these design equations, a fiber sorbent module configuration that selectively and continuously removes TBM from natural gas is developed
Advisors/Committee Members: Kawajiri, Yoshiaki (advisor), Jones, Christopher W. (advisor), Koros, William J. (advisor).
Subjects/Keywords: Fiber adsorbents; Mercaptan; Gas turbine corrosion
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APA (6th Edition):
Chen, G. (2013). Fiber adsorbents for tert-butyl mercaptan removal from pipeline grade natural gas. (Masters Thesis). Georgia Tech. Retrieved from http://hdl.handle.net/1853/52912
Chicago Manual of Style (16th Edition):
Chen, Grace. “Fiber adsorbents for tert-butyl mercaptan removal from pipeline grade natural gas.” 2013. Masters Thesis, Georgia Tech. Accessed February 26, 2020.
http://hdl.handle.net/1853/52912.
MLA Handbook (7th Edition):
Chen, Grace. “Fiber adsorbents for tert-butyl mercaptan removal from pipeline grade natural gas.” 2013. Web. 26 Feb 2020.
Vancouver:
Chen G. Fiber adsorbents for tert-butyl mercaptan removal from pipeline grade natural gas. [Internet] [Masters thesis]. Georgia Tech; 2013. [cited 2020 Feb 26].
Available from: http://hdl.handle.net/1853/52912.
Council of Science Editors:
Chen G. Fiber adsorbents for tert-butyl mercaptan removal from pipeline grade natural gas. [Masters Thesis]. Georgia Tech; 2013. Available from: http://hdl.handle.net/1853/52912
Georgia Tech
2.
Jaini, Rajiv.
Mass-transfer correlations for the dual bed colloidal suspension reactor.
Degree: MS, Chemical and Biomolecular Engineering, 2013, Georgia Tech
URL: http://hdl.handle.net/1853/50210
► To meet the growing energy world demands, and in conjunction, lower CO2 production levels, near zero emission energy sources must be pushed to the forefront…
(more)
▼ To meet the growing energy world demands, and in conjunction, lower CO2 production levels, near zero emission energy sources must be pushed to the forefront as alternatives to fossil fuels. Photoelectrochemical (PEC) cells are a potential alternative to fossil fuels and have recently generated much interest because of their potential to electrolyze water into hydrogen fuel from sunlight. But in order to be competitive with fossil fuels, understanding the mass-transfer limitations in PEC systems is critical. This work focuses on the addressing the mass-transfer limitations in a conceptually novel PEC cell reactor, the Dual Bed Colloidal Suspension Reactor (DBCSR).
Mass-transfer correlations for the DBCSR are presented. The correlations are based on experimental data obtained using two fabricated diffusion cells. The working correlation representative of both cells is given.
An analysis of the orientation of the gas sparger suggests that the transport phenomena in both cells is not the same, and therefore using two correlations to represent similar systems is justified. An energy analysis is presented that shows that gas sparging is a low energy consumption option to mitigate mass-transfer limitations. Future work is suggested for better understanding the mass-transfer behavior in the DBCSR.
Advisors/Committee Members: Fuller, Thomas F. (advisor), Kohl, Paul (committee member), Koros, William J. (committee member).
Subjects/Keywords: Dual bed colloidal suspension reactor; Gas sparging; Mass transfer; Photoelectrochemistry; Renewable energy sources; Solar cells; Electrolytic cells
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APA (6th Edition):
Jaini, R. (2013). Mass-transfer correlations for the dual bed colloidal suspension reactor. (Masters Thesis). Georgia Tech. Retrieved from http://hdl.handle.net/1853/50210
Chicago Manual of Style (16th Edition):
Jaini, Rajiv. “Mass-transfer correlations for the dual bed colloidal suspension reactor.” 2013. Masters Thesis, Georgia Tech. Accessed February 26, 2020.
http://hdl.handle.net/1853/50210.
MLA Handbook (7th Edition):
Jaini, Rajiv. “Mass-transfer correlations for the dual bed colloidal suspension reactor.” 2013. Web. 26 Feb 2020.
Vancouver:
Jaini R. Mass-transfer correlations for the dual bed colloidal suspension reactor. [Internet] [Masters thesis]. Georgia Tech; 2013. [cited 2020 Feb 26].
Available from: http://hdl.handle.net/1853/50210.
Council of Science Editors:
Jaini R. Mass-transfer correlations for the dual bed colloidal suspension reactor. [Masters Thesis]. Georgia Tech; 2013. Available from: http://hdl.handle.net/1853/50210
3.
Fadiran, Oluwatimilehin Olutayo.
Characterization and use of pollen as a biorenewable filler for polymer composites.
Degree: PhD, Chemical and Biomolecular Engineering, 2015, Georgia Tech
URL: http://hdl.handle.net/1853/54900
► Fillers are often incorporated in polymer matrices in order to improve cost, mechanical, thermal, and transport properties. This work explores the hypothesis that pollen, a…
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▼ Fillers are often incorporated in polymer matrices in order to improve cost, mechanical, thermal, and transport properties. This work explores the hypothesis that pollen, a natural particle, has the potential to be an effective biorenewable reinforcing filler due to its unique surface architectures, high strength, chemical stability, and low density. Pollens from sources such as ragweed plants are ubiquitous natural materials that are based on sustainable, non-food resources. Pollen is a remarkable example of evolutionary-optimized microscale particle with structures and/or chemistries tailored for effective adhesion to a variety of surfaces and protection of genetic material under different dynamic and environmental conditions. The pollen shell is perhaps the most chemically resistant naturally occurring material. As many pollens achieve pollination simply by being carried by wind, they are very light-weight. These properties make pollen an attractive option as a natural filler for polymers. This research aims to characterize pollen interfacial properties and utilize pollen as an effective reinforcing filler in polymer materials. In this work, interfacial properties are characterized using Fourier transform infrared spectroscopy (FTIR), the BET method, and inverse liquid chromatography (ILC). These techniques were useful in determining the effect of surface treatments and further chemical modifications on pollen interfacial properties. Characterizing these properties allowed for improved understanding and utilization of pollen as a filler by revealing the enhanced surface interactions and surface properties of acid-base treated pollens when compared to as received untreated pollens. Epoxy and polyvinyl acetate (PVAc) matrices were used to demonstrate the effectiveness of pollen as a filler, as a function of pollen loading and surface treatments/chemical modifications. Scanning electron microscopy (SEM) was used to determine interfacial morphology, a high throughput mechanical characterization device (HTMECH) was used to determine mechanical properties, and differential scanning calorimetry (DSC) was used to determine glass transition behavior. In epoxy, pollen was an effective load bearing filler only after modifying its surface with acid-base hydrolysis. In PVAc, pollen was an effective load bearing filler only after an additional functionalization with a silane coupling agent. Finally, the species of pollen incorporated in PVAc matrices was varied in order determine the effect of the size of surface nano- and micro- structures on wetting, adhesion, and composite properties. Composites containing pollen displayed enhanced wetting and interfacial adhesion when compared to composites with smooth silica particles. Additionally, it was observed that pollen with smaller surface structures were wetted more effectively by the polymer matrix than pollen with larger structures. However, mechanical properties did not suggest significant changes in interfacial adherence with varied pollen microstructure size. The results of…
Advisors/Committee Members: Meredith, J. Carson (advisor), Shofner, Meisha (advisor), Ludovice, Peter (advisor), Deng, Yulin (advisor), Koros, William (advisor).
Subjects/Keywords: Polymer composites; Pollen; Mechanical properties; Fillers; Sustainability; Interfacial properties; Functionalization
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APA (6th Edition):
Fadiran, O. O. (2015). Characterization and use of pollen as a biorenewable filler for polymer composites. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/54900
Chicago Manual of Style (16th Edition):
Fadiran, Oluwatimilehin Olutayo. “Characterization and use of pollen as a biorenewable filler for polymer composites.” 2015. Doctoral Dissertation, Georgia Tech. Accessed February 26, 2020.
http://hdl.handle.net/1853/54900.
MLA Handbook (7th Edition):
Fadiran, Oluwatimilehin Olutayo. “Characterization and use of pollen as a biorenewable filler for polymer composites.” 2015. Web. 26 Feb 2020.
Vancouver:
Fadiran OO. Characterization and use of pollen as a biorenewable filler for polymer composites. [Internet] [Doctoral dissertation]. Georgia Tech; 2015. [cited 2020 Feb 26].
Available from: http://hdl.handle.net/1853/54900.
Council of Science Editors:
Fadiran OO. Characterization and use of pollen as a biorenewable filler for polymer composites. [Doctoral Dissertation]. Georgia Tech; 2015. Available from: http://hdl.handle.net/1853/54900
Georgia Tech
4.
Olanrewaju, Kayode Olaseni.
The rheology and phase separation kinetics of mixed-matrix membrane dopes.
Degree: PhD, Chemical Engineering, 2011, Georgia Tech
URL: http://hdl.handle.net/1853/39466
► Mixed-matrix hollow fiber membranes are being developed to offer more efficient gas separations applications than what the current technologies allow. Mixed-matrix membranes (MMMs) are membranes…
(more)
▼ Mixed-matrix hollow fiber membranes are being developed to offer more efficient gas separations applications than what the current technologies allow. Mixed-matrix membranes (MMMs) are membranes in which molecular sieves incorporated in a polymer matrix do separation between gas mixtures based on the molecular size difference and/or adsorption properties of the component gases vis-à-vis the porous structure and the nature of adsorption sites in the molecular sieve. The development of MMMs to deliver on its promises has however been slow. The major challenges encountered in the efficient development of MMMs are associated with some of the paradigm shifts involved in their processing. For instance, mixed-matrix hollow fiber membranes are prepared by a dry-wet jet spinning method. For an efficient large scale processing of hollow fibers the rheology and kinetics of phase separation of the MMM dopes are important control variables in the process design. Therefore, this research thesis aims to study the rheology and phase separation kinetics of mixed-matrix membrane dopes.
In research efforts to develop predictive models for the shear rheology of suspensions of zeolite particles in polymer solutions it was found that MFI zeolite suspensions have relative viscosities that dramatically exceed the Krieger-Dougherty predictions for hard sphere suspensions. Our investigations show that the major origin of this discrepancy is the selective absorption of solvent molecules from the suspending polymer solution into the zeolite pores. Consequently, both the viscosity of the polymer solution and the particle contribution to the suspension viscosity are greatly increased. A predictive model for the viscosity of porous zeolite suspensions incorporating a solvent absorption parameter, α, into the Krieger-Dougherty model was developed. We experimentally determined the solvent absorption parameter and our results are in good agreement with the theoretical pore volume of MFI particles. In addition, fundamental studies were conducted with spherical nonporous silica suspensions to elucidate the role of colloidal and hydrodynamic forces on the rheology of mixed-matrix membrane dopes.
Also in this thesis, details of a novel microfluidic device that enables measurements of the phase separation kinetics via video-microscopy are presented. Our device provides a well-defined sample geometry and controlled atmosphere for in situ tracking of the phase separation process. We have used this technique to quantify the phase separation kinetics (PSK) of polymer solutions and MMM dopes upon contact with an array of relevant nonsolvent. For the polymer solution, we found that PSK is governed by the micro-rheological and thermodynamic properties of the polymer solution and nonsolvent. For the MMM dopes, we found that the PSK is increased by increased particles surface area as a result of surface diffusion enhancement. In addition, it was found that the dispersed particles alter the thermodynamic quality of the dope based on the hydrophilic and porous…
Advisors/Committee Members: Breedveld, Victor (Committee Chair), Bucknall, David (Committee Member), Grover, Martha (Committee Member), Koros, William (Committee Member), Meredith, Carson (Committee Member).
Subjects/Keywords: Polymer solution; Rheology; Phase separtion kinetics; Membranes; Suspensions; Zeolite particles; Membranes (Technology); Separation (Technology); Zeolites; Rheology; Liquation
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APA (6th Edition):
Olanrewaju, K. O. (2011). The rheology and phase separation kinetics of mixed-matrix membrane dopes. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/39466
Chicago Manual of Style (16th Edition):
Olanrewaju, Kayode Olaseni. “The rheology and phase separation kinetics of mixed-matrix membrane dopes.” 2011. Doctoral Dissertation, Georgia Tech. Accessed February 26, 2020.
http://hdl.handle.net/1853/39466.
MLA Handbook (7th Edition):
Olanrewaju, Kayode Olaseni. “The rheology and phase separation kinetics of mixed-matrix membrane dopes.” 2011. Web. 26 Feb 2020.
Vancouver:
Olanrewaju KO. The rheology and phase separation kinetics of mixed-matrix membrane dopes. [Internet] [Doctoral dissertation]. Georgia Tech; 2011. [cited 2020 Feb 26].
Available from: http://hdl.handle.net/1853/39466.
Council of Science Editors:
Olanrewaju KO. The rheology and phase separation kinetics of mixed-matrix membrane dopes. [Doctoral Dissertation]. Georgia Tech; 2011. Available from: http://hdl.handle.net/1853/39466
Georgia Tech
5.
Achoundong, Carine Saha Kuete.
Engineering economical membrane materials for aggressive sour gas separations.
Degree: PhD, Chemical and Biomolecular Engineering, 2013, Georgia Tech
URL: http://hdl.handle.net/1853/50289
► The goal is of this project was to identify principles to guide the development of high performance dense film membranes for natural gas sweetening using…
(more)
▼ The goal is of this project was to identify principles to guide the development of high performance dense film membranes for natural gas sweetening using hydrogen sulfide and carbon dioxide gas mixtures as models under aggressive sour gas feed conditions. To achieve this goal, three objectives were developed to guide this research.
The first objective was to study the performance of cellulose acetate (CA) and an advanced crosslinkable polyimide (PDMC) dense film membrane for H₂S separation from natural gas.
The second objective was to engineer those polymers to produce membrane materials with superior performance as measured by efficiency, productivity, and plasticization resistance, and the third objective was to determine the separation performance of these engineered membrane materials under more aggressive, realistic natural gas feeds, and to perform a detailed transport analysis of the factors that impact their performance.
Work on the first objective showed that in neat CA, penetrant transport is controlled by both the solubility and mobility selectivity, with the former being more dominant, leading to a high overall CO₂/CH₄ (33) and H₂S/CH₄ (35) ideal selectivities. However, in uncrosslinked PDMC, H₂S/CH₄ selectivity favored sorption only, whereas CO₂/CH₄ selectivity favored both mobility and sorption selectivity, leading to a high CO₂/CH₄ (37) but low H₂S/CH₄ (12) ideal selectivities. However, the latter polymer showed more plasticization resistance for CO₂.
In the second objective, both materials were engineered. A new technique referred to as “GCV-Modification” was introduced in which cellulose acetate was grafted using vinyltrimethoxysilane (VTMS), then hydrolyzed and condensed to form a polymer network. PDMC was also covalently crosslinked to enhance its performance. GCV-Modified CA showed significant performance improvements for H₂S and CO₂ removal; the permeability of CO₂ and H₂S were found to be 139 and 165 Barrer, respectively, which represented a 30X and 34X increase compared to the pristine CA polymer. The H₂S/CH₄ and CO₂/CH₄ ideal selectivities were found to be 39 and 33, respectively. Crosslinked PDMC showed a higher CO₂/CH₄ selectivity of 38 with a better plasticization resistance for CO₂ and H₂S.
In the third objective, these materials were tested under aggressive ternary mixtures of H₂S/CO₂/CH₄ with both vacuum and nonvacuum downstream. Even under aggressive feed conditions, GCV-Modified CA showed better performance vs. PDMC, and it remained were fairly stable, making it a potential candidate for aggressive sour gas separations, not only because of its significantly higher productivity, which will help decrease the surface area needed for separation, thereby reducing operating costs, but also because of the lower cost of the raw material GCV-Modified CA compared to PDMC.
Advisors/Committee Members: Koros, William J. (advisor), Jacob, Karl (committee member), Meredith, Carson (committee member), Nair, Sankar (committee member), Walton, Krista (committee member).
Subjects/Keywords: Acid gas; Sour gas; Membrane gas separations; Polymer membrane; Cellulose acetate; PDMC; Natural gas; Membrane separation; Hydrogen sulfide; Carbon dioxide
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APA (6th Edition):
Achoundong, C. S. K. (2013). Engineering economical membrane materials for aggressive sour gas separations. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/50289
Chicago Manual of Style (16th Edition):
Achoundong, Carine Saha Kuete. “Engineering economical membrane materials for aggressive sour gas separations.” 2013. Doctoral Dissertation, Georgia Tech. Accessed February 26, 2020.
http://hdl.handle.net/1853/50289.
MLA Handbook (7th Edition):
Achoundong, Carine Saha Kuete. “Engineering economical membrane materials for aggressive sour gas separations.” 2013. Web. 26 Feb 2020.
Vancouver:
Achoundong CSK. Engineering economical membrane materials for aggressive sour gas separations. [Internet] [Doctoral dissertation]. Georgia Tech; 2013. [cited 2020 Feb 26].
Available from: http://hdl.handle.net/1853/50289.
Council of Science Editors:
Achoundong CSK. Engineering economical membrane materials for aggressive sour gas separations. [Doctoral Dissertation]. Georgia Tech; 2013. Available from: http://hdl.handle.net/1853/50289
Georgia Tech
6.
Kim, Hyung Ju.
Modified mesoporous silica membranes for separation applications.
Degree: PhD, Chemical and Biomolecular Engineering, 2013, Georgia Tech
URL: http://hdl.handle.net/1853/52175
► The main theme of this dissertation is the fabrication and analysis of modified mesoporous silica membranes for separation applications. Synthesis methods for mesoporous silica membranes…
(more)
▼ The main theme of this dissertation is the fabrication and analysis of modified mesoporous silica membranes for separation applications. Synthesis methods for mesoporous silica membranes have been developed to enhance the transport performance and quality of the membranes, such as permeability, pore volume, and surface area. Then, synthesized membranes were modified with different organic groups to tailor selectivity in separations. The collected studies of modified mesoporous silica membranes showed that appropriate functionalization on newly synthesized novel membranes leads to promising structural and permeation properties. First, a seeded growth method was developed for synthesis of MCM-48 membranes on alumina supports, thereby extending the seeded growth technique used for zeolite membranes to mesoporous silica membrane synthesis. The surface properties of the MCM-48 membranes were then modified by silylation with hexamethyldisilazane (HMDS). In comparison to MCM-48 membranes previously synthesized by the in situ growth technique, much less silica infiltration into the alumina support was observed. The pore structure of the MCM-48 membranes demonstrated that a large accessible pore volume was available for molecular permeation and pore modification to tailor selectivity. The gas permeation properties of the calcined and silylated MCM-48 membranes were consistent with a Knudsen-like mechanism, albeit with a substantial influence of gas-solid interactions in the mesopores. The silylated MCM-48 membranes were evaluated for pervaporative separation of ethanol (EtOH), methyl ethyl ketone (MEK), and ethyl acetate (EA) from their dilute aqueous solutions. The synthesized membranes exhibited high pervaporative separation factors and organic fluxes. The selective separation of organic/water mixtures with MCM-48 membranes were attributed to both the organophilic nature of the surface and the effective pore size of the silylated mesopores. Next, the synthesis and organic/water separation properties of mesoporous silica membranes supported on low-cost and scalable polymeric (polyamide-imide) hollow fibers and modified by trimethylsilylation with HMDS was studied. Thin, defect-free membranes that exhibited high gas permeances consistent with Knudsen-like diffusion through the mesopores were prepared. Silylation of these membranes did not affect the integrity of the mesoporous silica structure and the underlying polymeric hollow fiber, but led to capping of the surface silanol groups in the mesopores with trimethylsilyl groups. The silylated mesoporous membranes were evaluated for pervaporative separation of EtOH, MEK, EA, iso-butanol, and n-butanol from their dilute aqueous solutions. The membranes showed higher separation factors than those of flat membranes, along with high organic fluxes. The large increase in hydrophobicity of the membranes upon silylation allowed upgrading of the feed mixtures to permeate streams with considerably higher organic content. The selective separation of organic/water mixtures with the…
Advisors/Committee Members: Jones, Christopher (advisor), Nair, Sankar (advisor), Koros, William (committee member), Meredith, Carson (committee member), Wilkinson, Angus (committee member).
Subjects/Keywords: MCM-48; Seeded growth; Separation; Pervaporation; Membrane; Mesoporous silica; Gas separation; Hollow fiber; CO2 capture
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APA ·
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APA (6th Edition):
Kim, H. J. (2013). Modified mesoporous silica membranes for separation applications. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/52175
Chicago Manual of Style (16th Edition):
Kim, Hyung Ju. “Modified mesoporous silica membranes for separation applications.” 2013. Doctoral Dissertation, Georgia Tech. Accessed February 26, 2020.
http://hdl.handle.net/1853/52175.
MLA Handbook (7th Edition):
Kim, Hyung Ju. “Modified mesoporous silica membranes for separation applications.” 2013. Web. 26 Feb 2020.
Vancouver:
Kim HJ. Modified mesoporous silica membranes for separation applications. [Internet] [Doctoral dissertation]. Georgia Tech; 2013. [cited 2020 Feb 26].
Available from: http://hdl.handle.net/1853/52175.
Council of Science Editors:
Kim HJ. Modified mesoporous silica membranes for separation applications. [Doctoral Dissertation]. Georgia Tech; 2013. Available from: http://hdl.handle.net/1853/52175
Georgia Tech
7.
Bollini, Praveen P.
Amine-oxide adsorbents for post-combustion CO₂ capture.
Degree: PhD, Chemical and Biomolecular Engineering, 2013, Georgia Tech
URL: http://hdl.handle.net/1853/52908
► Amine functionalized silicas are promising chemisorbent materials for post-combustion CO₂ capture due to the high density of active sites per unit mass of adsorbent that…
(more)
▼ Amine functionalized silicas are promising chemisorbent materials for post-combustion CO₂ capture due to the high density of active sites per unit mass of adsorbent that can be obtained by tuning the synthesis protocol, thus resulting in high equilibrium CO₂ adsorption capacities. However, when compared to physisorbents, they have a few disadvantages. Firstly, oxidative degradation of the amine groups reduces the lifetime of these adsorbent materials. Furthermore, rapid heat release following the reaction between amines and CO₂ results in large local temperature spikes which may adversely affect adsorption equilibria and kinetics. Thirdly, there is a lack of fundamental understanding of CO₂-amine adsorption thermodynamics, which is key to scaling up these materials to an industrial-scale adsorption process. In this dissertation the qualitative and quantitative understanding of these three critical aspects of aminosilica adsorbents have been furthered so these materials can be better evaluated and further tuned as adsorbents for post-combustion CO₂ capture applications.
Advisors/Committee Members: Jones, Christopher W. (advisor), Walton, Krista (committee member), Nenes, Athanasios (committee member), Sholl, David S. (committee member), Koros, William J. (committee member).
Subjects/Keywords: Adsorption; CO₂ capture; Mesoporous materials; Amine
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APA (6th Edition):
Bollini, P. P. (2013). Amine-oxide adsorbents for post-combustion CO₂ capture. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/52908
Chicago Manual of Style (16th Edition):
Bollini, Praveen P. “Amine-oxide adsorbents for post-combustion CO₂ capture.” 2013. Doctoral Dissertation, Georgia Tech. Accessed February 26, 2020.
http://hdl.handle.net/1853/52908.
MLA Handbook (7th Edition):
Bollini, Praveen P. “Amine-oxide adsorbents for post-combustion CO₂ capture.” 2013. Web. 26 Feb 2020.
Vancouver:
Bollini PP. Amine-oxide adsorbents for post-combustion CO₂ capture. [Internet] [Doctoral dissertation]. Georgia Tech; 2013. [cited 2020 Feb 26].
Available from: http://hdl.handle.net/1853/52908.
Council of Science Editors:
Bollini PP. Amine-oxide adsorbents for post-combustion CO₂ capture. [Doctoral Dissertation]. Georgia Tech; 2013. Available from: http://hdl.handle.net/1853/52908
Georgia Tech
8.
Robbins, Thomas.
Small-scale heat-driven adsorption cooling.
Degree: PhD, Mechanical Engineering, 2014, Georgia Tech
URL: http://hdl.handle.net/1853/52982
► Heat driven adsorption cycles use heat sources ranging in temperature from 80 - 150 °C to provide cooling, and have been used in both air…
(more)
▼ Heat driven adsorption cycles use heat sources ranging in temperature from 80 - 150 °C to provide cooling, and have been used in both air conditioning and refrigeration applications. Adsorbent heat pumps operate with low cost, simple components, and very little vibration, making them appealing as an alternative heat pump technology. However, they have been limited thus far to commercial and industrial scale applications. To date, adsorption systems have predominantly used natural or industrial waste streams as heat sources in the 10s of kW range. This work expands the scope of adsorption applications to include heat driven cooling at small capacities (watts) and mobile cooling without electronic controls. Autonomous heat driven adsorption system controls are proposed and tested for these systems. Component and system level models are developed for design and assessment. Major trends in system performance with scale are identified and the causes for these scaling effects are presented. New adsorbent bed designs are proposed and modeled for small-scale adsorption systems. The small-scale adsorbent bed designs are fabricated and tested. Models are validated and refined based on the experimental results. Through a combination of modeling and experimental results, this work demonstrates the feasibility of adsorption system application at capacities that two orders of magnitude lower than any previously demonstrated work.
Advisors/Committee Members: Garimella, Srinivas (advisor), Graham, Samuel (committee member), Jeter, Sheldon (committee member), Koros, William (committee member), Walton, Krista (committee member).
Subjects/Keywords: Adsorption; Microscale; Small-scale; Heat driven; Activated carbon; Ammonia; Heat pump; Autonomous
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APA (6th Edition):
Robbins, T. (2014). Small-scale heat-driven adsorption cooling. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/52982
Chicago Manual of Style (16th Edition):
Robbins, Thomas. “Small-scale heat-driven adsorption cooling.” 2014. Doctoral Dissertation, Georgia Tech. Accessed February 26, 2020.
http://hdl.handle.net/1853/52982.
MLA Handbook (7th Edition):
Robbins, Thomas. “Small-scale heat-driven adsorption cooling.” 2014. Web. 26 Feb 2020.
Vancouver:
Robbins T. Small-scale heat-driven adsorption cooling. [Internet] [Doctoral dissertation]. Georgia Tech; 2014. [cited 2020 Feb 26].
Available from: http://hdl.handle.net/1853/52982.
Council of Science Editors:
Robbins T. Small-scale heat-driven adsorption cooling. [Doctoral Dissertation]. Georgia Tech; 2014. Available from: http://hdl.handle.net/1853/52982
Georgia Tech
9.
Zhang, Chen.
Zeolitic imidazolate framework (ZIF)-based membranes and sorbents for advanced olefin/paraffin separations.
Degree: PhD, Chemical and Biomolecular Engineering, 2014, Georgia Tech
URL: http://hdl.handle.net/1853/53422
► Propylene is one of the most important feedstocks of the petrochemical industry with an estimated 2015 worldwide demand of 100 million tons. Retrofitting conventional C3…
(more)
▼ Propylene is one of the most important feedstocks of the petrochemical industry with an estimated 2015 worldwide demand of 100 million tons. Retrofitting conventional C3 splitters is highly desirable due to the huge amount of thermal energy required to separate propylene from propane. Membrane separation is among the alternatives that both academia and industry have actively studied during the past decades, however; many challenges remain to advance membrane separation as a scalable technology for energy-efficient propylene/propane separations.
The overarching goal of this research is to provide a framework for development of scalable ZIF-based mixed-matrix membrane that is able to deliver attractive transport properties for advanced gas separations. Zeolitic imidazolate frameworks (ZIFs) were pursued instead of conventional molecular sieves (zeolites and carbon molecular sieves) to form mixed-matrix membrane due to their intrinsic compatibility with high Tg glassy polymers. A systematic study of adsorption and diffusion in zeolitic imidazolate framework-8 (ZIF-8) suggests that this material is remarkably kinetically selective for C3 and C4 hydrocarbons and therefore promising for membrane-based gas separation and adsorptive separation. As a result, ZIF-8 was used to form mixed-matrix dense film membranes with polyimide 6FDA-DAM at varied particle loadings and it was found that ZIF-8 significantly enhanced propylene/propane separation performance beyond the “permeability-selectivity” trade-off curve for polymeric materials. Eventually, this research advanced ZIF-based mixed-matrix membrane into a scalable technology by successfully forming high-loading dual-layer ZIF-8/6FDA-DAM asymmetric mixed-matrix hollow fiber membranes with attractive propylene/propane selectivity.
Advisors/Committee Members: Koros, William J. (advisor), Jones, Christopher W. (committee member), Nair, Sankar (committee member), Walton, Krista S. (committee member), Griffin, Anselm (committee member).
Subjects/Keywords: Olefin/paraffin separations; Mixed-matrix membrane; Zeolitic imidazolate frameworks (ZIFs); Hollow fiber membrane; Sorbents
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APA (6th Edition):
Zhang, C. (2014). Zeolitic imidazolate framework (ZIF)-based membranes and sorbents for advanced olefin/paraffin separations. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/53422
Chicago Manual of Style (16th Edition):
Zhang, Chen. “Zeolitic imidazolate framework (ZIF)-based membranes and sorbents for advanced olefin/paraffin separations.” 2014. Doctoral Dissertation, Georgia Tech. Accessed February 26, 2020.
http://hdl.handle.net/1853/53422.
MLA Handbook (7th Edition):
Zhang, Chen. “Zeolitic imidazolate framework (ZIF)-based membranes and sorbents for advanced olefin/paraffin separations.” 2014. Web. 26 Feb 2020.
Vancouver:
Zhang C. Zeolitic imidazolate framework (ZIF)-based membranes and sorbents for advanced olefin/paraffin separations. [Internet] [Doctoral dissertation]. Georgia Tech; 2014. [cited 2020 Feb 26].
Available from: http://hdl.handle.net/1853/53422.
Council of Science Editors:
Zhang C. Zeolitic imidazolate framework (ZIF)-based membranes and sorbents for advanced olefin/paraffin separations. [Doctoral Dissertation]. Georgia Tech; 2014. Available from: http://hdl.handle.net/1853/53422
Georgia Tech
10.
Tiernan, Aubrey Rose.
Development of a pancreatic substitute based on genetically engineered intestinal endocrine cells.
Degree: PhD, Chemical and Biomolecular Engineering, 2014, Georgia Tech
URL: http://hdl.handle.net/1853/53987
► Cell-based insulin therapies can potentially improve glycemic regulation in insulin dependent diabetes patients and thus help reduce secondary complications. The long-term goal of our work…
(more)
▼ Cell-based insulin therapies can potentially improve glycemic regulation in insulin dependent diabetes patients and thus help reduce secondary complications. The long-term goal of our work is to engineer autologous insulin-secreting intestinal endocrine cells as a non-beta cell approach to alleviate donor cell shortage and immune rejection issues associated with islet transplantation. These cells have been chosen for their endogenous similarity to beta cells, but generating cell constructs with sufficient insulin secretion for therapeutic effect has proven challenging. Previous work in our lab showed that a tissue engineered pancreatic substitute (TEPS) based on an engineered insulin-secreting L cell line, GLUTag-INS, was insufficient in affecting blood glucose levels in streptozotocin-induced diabetic mice, but promising since human insulin was detected in the blood. The objective of this project was therefore to fabricate an improved TEPS based on GLUTag-INS cells and evaluate its suitability as a standalone diabetes therapy. To achieve this objective, the following specific aims were (1) to investigate gene incorporation as a strategy to enhance recombinant insulin secretion from GLUTag-INS cells; (2) to develop and characterize a TEPS in vitro based on a microcapsule system containing improved GLUTag-INS cells with bioluminescence monitoring capability; and (3) to assess therapeutic efficacy of the graft in a diabetic, immune-competent mouse model and use bioluminescence monitoring to elucidate in vivo transplant behavior. This thesis therefore reports on the progression of studies from the genetic and molecular levels for improved insulin secretion per-cell, to the tissue level for enhanced secretion per-graft, and lastly to the preclinical level for therapeutic assessment in a diabetic mouse model.
Advisors/Committee Members: Sambanis, Athanassios (advisor), Koros, William (committee member), Le Doux, Joe (committee member), Thule, Peter M. (committee member), Champion, Julie A. (committee member).
Subjects/Keywords: Diabetes; Bioluminescence; Intestinal L cells; Pancreatic substitute; Cell encapsulation
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APA (6th Edition):
Tiernan, A. R. (2014). Development of a pancreatic substitute based on genetically engineered intestinal endocrine cells. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/53987
Chicago Manual of Style (16th Edition):
Tiernan, Aubrey Rose. “Development of a pancreatic substitute based on genetically engineered intestinal endocrine cells.” 2014. Doctoral Dissertation, Georgia Tech. Accessed February 26, 2020.
http://hdl.handle.net/1853/53987.
MLA Handbook (7th Edition):
Tiernan, Aubrey Rose. “Development of a pancreatic substitute based on genetically engineered intestinal endocrine cells.” 2014. Web. 26 Feb 2020.
Vancouver:
Tiernan AR. Development of a pancreatic substitute based on genetically engineered intestinal endocrine cells. [Internet] [Doctoral dissertation]. Georgia Tech; 2014. [cited 2020 Feb 26].
Available from: http://hdl.handle.net/1853/53987.
Council of Science Editors:
Tiernan AR. Development of a pancreatic substitute based on genetically engineered intestinal endocrine cells. [Doctoral Dissertation]. Georgia Tech; 2014. Available from: http://hdl.handle.net/1853/53987
Georgia Tech
11.
Oh, Kyung Hee.
Effect of shear, elongation and phase separation in hollow fiber membrane spinning.
Degree: PhD, Chemical and Biomolecular Engineering, 2014, Georgia Tech
URL: http://hdl.handle.net/1853/53992
► The spinning process of hollow fiber membranes was investigated with regards to two fundamental phenomena: flow (shear and elongation) and phase separation. Quantitative analysis of…
(more)
▼ The spinning process of hollow fiber membranes was investigated with regards to two fundamental phenomena: flow (shear and elongation) and phase separation. Quantitative analysis of phase separation kinetics of binary (polymer/solvent) and ternary (polymer/solvent/volatile co-solvent) polymer solution was carried out with a newly developed microfluidic device. The device enables visualization of in situ phase separation and structure formation in controlled vapor and liquid environments. Results from these studies indicated that there was a weak correlation between phase separation kinetics and macroscopic defect (macrovoid) formation. In addition, the effect of shear and elongation on membrane morphology was tested by performing fiber extrusion through microfluidic channels. It was found that the membrane morphology is dominated by different factors depending on the rate of deformation. At high shear rates typical of spinning processes, shear was found to induce macrovoid formation through normal stresses, while elongation suppressed macroscopic defect formation. Furthermore, draw resonance, one of the key instabilities that can occur during fiber spinning, was investigated. It was found that draw resonance occurs at aggressive elongation condition, and could be suppressed by enhanced phase separation kinetics. These results can be used as guidelines for predicting hollow fiber membrane spinnability.
Advisors/Committee Members: Breedveld, Victor (advisor), Meredith, Carson (committee member), Lu, Hang (committee member), Koros, William J. (committee member), Beckham, Haskell W. (committee member).
Subjects/Keywords: Rheology; Polymer solutions; Membrane dopes; Hollow fiber membrane spinning; Phase separation; Microfluidics; Fiber spinning instabilities
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APA (6th Edition):
Oh, K. H. (2014). Effect of shear, elongation and phase separation in hollow fiber membrane spinning. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/53992
Chicago Manual of Style (16th Edition):
Oh, Kyung Hee. “Effect of shear, elongation and phase separation in hollow fiber membrane spinning.” 2014. Doctoral Dissertation, Georgia Tech. Accessed February 26, 2020.
http://hdl.handle.net/1853/53992.
MLA Handbook (7th Edition):
Oh, Kyung Hee. “Effect of shear, elongation and phase separation in hollow fiber membrane spinning.” 2014. Web. 26 Feb 2020.
Vancouver:
Oh KH. Effect of shear, elongation and phase separation in hollow fiber membrane spinning. [Internet] [Doctoral dissertation]. Georgia Tech; 2014. [cited 2020 Feb 26].
Available from: http://hdl.handle.net/1853/53992.
Council of Science Editors:
Oh KH. Effect of shear, elongation and phase separation in hollow fiber membrane spinning. [Doctoral Dissertation]. Georgia Tech; 2014. Available from: http://hdl.handle.net/1853/53992
Georgia Tech
12.
Fu, Boyi.
Design and syntheses of hole and electron transport donor-acceptor polymeric semiconductors and their applications to organic field-effect transistors.
Degree: PhD, Chemical and Biomolecular Engineering, 2015, Georgia Tech
URL: http://hdl.handle.net/1853/54868
► The π-conjugated organic and polymeric semiconducting materials have attracted much attention in the past years due to their significant potential in applications to electronic and…
(more)
▼ The π-conjugated organic and polymeric semiconducting materials have attracted much attention in the past years due to their significant potential in applications to electronic and optoelectronic devices including organic field-effect transistors (OFETs), organic photovoltaics (OPVs), and organic light-emitting diodes (OLEDs), etc. Yet, organic and polymeric semiconductors still have challenges associated with their relatively low charge carrier (hole and electron) transport mobilities and ambient stability in OFET applications.
This dissertation discusses the molecular engineering on backbones and side-chains of π-conjugated semiconducting polymers to enhance the hole and electron field-effect mobilities. Three donor-acceptor copolymers, the hole transport (p-type) poly(hexathiophene-co-benzo- thiazole) (PBT6), the hole transport poly(thiophenes-benzothiadiazole-thiophenes-diketopyrrolo- pyrrole) (pTBTD), and the electron transport (n-type) poly(dithieno-diketopyrrolopyrrole-bithiazole) (PDBTz) have been developed. Besides, the effect of polymer side chains on polymer solution-processability and charge carrier transport properties was systematically investigated: a side chain 5-decylheptadecyl having the branching position remote from the polymer backbone merges the advantages of the improved solubility from traditional branched side chains in which the branch chains are close to polymer backbone and the effective π-π intermolecular interactions commonly associated with linear side chains. This indicates the potential of side chain engineering to facilitate the charge carrier transport performance of organic and polymeric semiconductors. Additionally, PDBTz solution-processing to OFETs based on non-halogenated solvents (xylenes and tetralin) was studied. The resultant thin-film OFET devices based on non-halogenated solvents exhibited similar film morphology and field-effect electron mobilities as the counterparts based on halogenated solvents, indicative of the feasibility of developing high mobility OFET devices through more environmentally-benign processing.
Advisors/Committee Members: Reichmanis, Elsa (advisor), Collard, David M. (committee member), Bredas, Jean-Luc (committee member), Koros, William J. (committee member), Hess, Dennis W. (committee member).
Subjects/Keywords: Hole transport polymer semiconductors; Electron transport polymer semiconductors; pi-Conjugated polymers; Organic field-effect transistors
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APA ·
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APA (6th Edition):
Fu, B. (2015). Design and syntheses of hole and electron transport donor-acceptor polymeric semiconductors and their applications to organic field-effect transistors. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/54868
Chicago Manual of Style (16th Edition):
Fu, Boyi. “Design and syntheses of hole and electron transport donor-acceptor polymeric semiconductors and their applications to organic field-effect transistors.” 2015. Doctoral Dissertation, Georgia Tech. Accessed February 26, 2020.
http://hdl.handle.net/1853/54868.
MLA Handbook (7th Edition):
Fu, Boyi. “Design and syntheses of hole and electron transport donor-acceptor polymeric semiconductors and their applications to organic field-effect transistors.” 2015. Web. 26 Feb 2020.
Vancouver:
Fu B. Design and syntheses of hole and electron transport donor-acceptor polymeric semiconductors and their applications to organic field-effect transistors. [Internet] [Doctoral dissertation]. Georgia Tech; 2015. [cited 2020 Feb 26].
Available from: http://hdl.handle.net/1853/54868.
Council of Science Editors:
Fu B. Design and syntheses of hole and electron transport donor-acceptor polymeric semiconductors and their applications to organic field-effect transistors. [Doctoral Dissertation]. Georgia Tech; 2015. Available from: http://hdl.handle.net/1853/54868
Georgia Tech
13.
George, Vyran.
Transport properties for ionic liquids used in next generation high capacity batteries.
Degree: PhD, Chemical and Biomolecular Engineering, 2015, Georgia Tech
URL: http://hdl.handle.net/1853/55495
► Using room temperature ionic liquids (RTILs) as electrolytes in Li-ion battery systems provides important safety and performance benefits over the more volatile, combustible organic solvents…
(more)
▼ Using room temperature ionic liquids (RTILs) as electrolytes in Li-ion battery systems provides important safety and performance benefits over the more volatile, combustible organic solvents currently used. However, in order to gain a more profound understanding of transport in these electrolytes, properties such as conductivity, transference numbers, and salt activity must be measured as a function of salt concentration. Experimental methods are proposed for calculating a complete set of transport properties for a room temperature ionic liquid system. These data are also used in conjunction with concentrated solution theory equations to develop a robust porous electrode model for advanced batteries. Furthermore, the effect of organic additives on the electrolyte conductivity, internal resistances and overall cell performance was studied for a RTIL-based electrolyte system.
Advisors/Committee Members: Fuller, Thomas (advisor), Yushin, Gleb (committee member), Koros, William (committee member), Kohl, Paul (committee member), Nenes, Athanasios (committee member).
Subjects/Keywords: Lithium ion; RTIL; Ionic liquids; Transport properties
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APA (6th Edition):
George, V. (2015). Transport properties for ionic liquids used in next generation high capacity batteries. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/55495
Chicago Manual of Style (16th Edition):
George, Vyran. “Transport properties for ionic liquids used in next generation high capacity batteries.” 2015. Doctoral Dissertation, Georgia Tech. Accessed February 26, 2020.
http://hdl.handle.net/1853/55495.
MLA Handbook (7th Edition):
George, Vyran. “Transport properties for ionic liquids used in next generation high capacity batteries.” 2015. Web. 26 Feb 2020.
Vancouver:
George V. Transport properties for ionic liquids used in next generation high capacity batteries. [Internet] [Doctoral dissertation]. Georgia Tech; 2015. [cited 2020 Feb 26].
Available from: http://hdl.handle.net/1853/55495.
Council of Science Editors:
George V. Transport properties for ionic liquids used in next generation high capacity batteries. [Doctoral Dissertation]. Georgia Tech; 2015. Available from: http://hdl.handle.net/1853/55495
Georgia Tech
14.
Conley, Mark Lewis.
Mechanistic investigations and optimizations of thermal stability in polyethylene and polyvinyl chloride blends.
Degree: PhD, Chemical and Biomolecular Engineering, 2015, Georgia Tech
URL: http://hdl.handle.net/1853/55532
► The thermal stability of two distinct blended polymer systems was examined. A model for polyethylene was used to investigate the vulnerability of polyethylene to premature…
(more)
▼ The thermal stability of two distinct blended polymer systems was examined. A model for polyethylene was used to investigate the vulnerability of polyethylene to premature crosslinking in industrial crosslinking conditions. Careful experiments were conducted to gather evidence of the interaction between a peroxide crosslinking agent and a specific antioxidant additive. Multiple lines of evidence were combined to propose a complete mechanism of interaction between the two species. The mechanism was further tested and a hypothesis was proposed for the reduction in premature crosslinking exhibited when the two species are present in polyethylene blends. A specific aspect of the proposed mechanism warranted further investigation on its own. The acid-catalyzed degradation of the peroxide initiator was thoroughly investigated. The thermal degradation of polyvinyl chloride was also studied. Model compounds were reacted with carboxylates to determine the relative rates of stabilization at various polymer defect sites. These model studies were combined with weight loss and color change investigations of bulk polymer systems. The knowledge gained from the model and polymer studies allowed for the proposal and examination of two novel stabilizing salt systems. The efficacy of the new stabilizers is presented.
Advisors/Committee Members: Liotta, Charles L. (advisor), Behrens, Sven (committee member), Koros, William (committee member), France, Stefan (committee member), Schork, Francis (committee member).
Subjects/Keywords: Polymer; Thermal stability
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APA (6th Edition):
Conley, M. L. (2015). Mechanistic investigations and optimizations of thermal stability in polyethylene and polyvinyl chloride blends. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/55532
Chicago Manual of Style (16th Edition):
Conley, Mark Lewis. “Mechanistic investigations and optimizations of thermal stability in polyethylene and polyvinyl chloride blends.” 2015. Doctoral Dissertation, Georgia Tech. Accessed February 26, 2020.
http://hdl.handle.net/1853/55532.
MLA Handbook (7th Edition):
Conley, Mark Lewis. “Mechanistic investigations and optimizations of thermal stability in polyethylene and polyvinyl chloride blends.” 2015. Web. 26 Feb 2020.
Vancouver:
Conley ML. Mechanistic investigations and optimizations of thermal stability in polyethylene and polyvinyl chloride blends. [Internet] [Doctoral dissertation]. Georgia Tech; 2015. [cited 2020 Feb 26].
Available from: http://hdl.handle.net/1853/55532.
Council of Science Editors:
Conley ML. Mechanistic investigations and optimizations of thermal stability in polyethylene and polyvinyl chloride blends. [Doctoral Dissertation]. Georgia Tech; 2015. Available from: http://hdl.handle.net/1853/55532
Georgia Tech
15.
Fu, Shilu.
CARBON MOLECULAR SIEVE (CMS) MEMBRANES STRUCTURE-PROPERTY RELATIONSHIPS.
Degree: PhD, Chemical and Biomolecular Engineering, 2015, Georgia Tech
URL: http://hdl.handle.net/1853/56194
► The goal of this work is to develop a framework to understand the material science options to fabricate novel, high performing separation CMS membranes. The…
(more)
▼ The goal of this work is to develop a framework to understand the material science options to fabricate novel, high performing separation CMS membranes. The transport and sorption properties of CMS membranes formed by pyrolysis under argon at 550 °C for four novel polyimide precursors referred to as 6FDA/DETDA, 6FDA:BPDA(1:1)/DETDA, 6FDA/DETDA:DABA(3:2) and 6FDA/1,5-ND:ODA(1:1) were reported and compared. The 6FDA/DETDA:DABA(3:2) derived CMS membranes showed the highest permeability and offered the greatest practical potential. The effects of pyrolysis conditions, including pyrolysis temperature; O2 doping; and precrosslinking, on the separation performance of 6FDA/DETDA:DABA(3:2) derived CMS membranes were reported and compared. The temperature dependence of both energetic and entropic selectivity and their contributions to overall diffusion selectivity of various types of CMS membranes are discussed in detail in this study. Finally, the viability of extending the promising separation performance obtained from 6FDA/DETDA:DABA(3:2) CMS dense film into hollow fiber morphology was also explored in this work.
Advisors/Committee Members: Koros, William J (committee member), Hess, Dennis W (committee member), Deng, Yulin (committee member), Reynolds, John (committee member), Sanders, Edgar S (committee member).
Subjects/Keywords: Carbon Molecular Sieve membranes; gas separation; pyrolysis; polyimide membrane
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APA (6th Edition):
Fu, S. (2015). CARBON MOLECULAR SIEVE (CMS) MEMBRANES STRUCTURE-PROPERTY RELATIONSHIPS. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/56194
Chicago Manual of Style (16th Edition):
Fu, Shilu. “CARBON MOLECULAR SIEVE (CMS) MEMBRANES STRUCTURE-PROPERTY RELATIONSHIPS.” 2015. Doctoral Dissertation, Georgia Tech. Accessed February 26, 2020.
http://hdl.handle.net/1853/56194.
MLA Handbook (7th Edition):
Fu, Shilu. “CARBON MOLECULAR SIEVE (CMS) MEMBRANES STRUCTURE-PROPERTY RELATIONSHIPS.” 2015. Web. 26 Feb 2020.
Vancouver:
Fu S. CARBON MOLECULAR SIEVE (CMS) MEMBRANES STRUCTURE-PROPERTY RELATIONSHIPS. [Internet] [Doctoral dissertation]. Georgia Tech; 2015. [cited 2020 Feb 26].
Available from: http://hdl.handle.net/1853/56194.
Council of Science Editors:
Fu S. CARBON MOLECULAR SIEVE (CMS) MEMBRANES STRUCTURE-PROPERTY RELATIONSHIPS. [Doctoral Dissertation]. Georgia Tech; 2015. Available from: http://hdl.handle.net/1853/56194
Georgia Tech
16.
Mangarella, Michael C.
Designed Carbide-derived Carbons for Ammonia Filtration.
Degree: PhD, Chemical and Biomolecular Engineering, 2015, Georgia Tech
URL: http://hdl.handle.net/1853/56197
► A series of carbide-derived carbons were synthesized with specific adsorptive sites to selectively separate ammonia gas from air. Two main strategies were utilized: 1. the…
(more)
▼ A series of carbide-derived carbons were synthesized with specific adsorptive sites to selectively separate ammonia gas from air. Two main strategies were utilized: 1. the inclusion of residual metal sites through the incomplete extraction of a metal atom from a carbide precursor and 2. The addition of acidic functional groups on the surface of a carbide-derived carbon through surface functionalization. The results from the first strategy showed that under certain synthesis conditions, the selection extraction of iron from iron carbide does not follow a traditional layer-by-layer extraction process previously observed for other carbides in literature. Instead, the extraction process is more complex, and allows for a large percentage of residual iron to be retained as well-dispersed iron chloride nanoparticles. These tailored adsorbents were subsequently shown to be active against ammonia in dynamic breakthrough experiments under both dry and humid conditions, and it was proposed that iron chloride ammine complexes are formed. The results from the second strategy highlight that surface functionalization of these highly nanoporous carbonaceous materials significantly improve the dynamic ammonia adsorption capacity of these materials. The acidification of carbide-derived carbons with nitric acid provide a high density of acidic functional groups, and are shown to be very effectively utilized. Findings concerning the type of each functional group are also discussed. Finally, recommendations for future studies and extensions of this work are discussed.
Advisors/Committee Members: Walton, Krista S (advisor), Jones, Christopher W (committee member), Koros, William J (committee member), Deng, Yulin (committee member), Yushin, Gleb N (committee member).
Subjects/Keywords: Carbide-derived carbons; Adsorbents; Nanoporous; Separations
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APA (6th Edition):
Mangarella, M. C. (2015). Designed Carbide-derived Carbons for Ammonia Filtration. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/56197
Chicago Manual of Style (16th Edition):
Mangarella, Michael C. “Designed Carbide-derived Carbons for Ammonia Filtration.” 2015. Doctoral Dissertation, Georgia Tech. Accessed February 26, 2020.
http://hdl.handle.net/1853/56197.
MLA Handbook (7th Edition):
Mangarella, Michael C. “Designed Carbide-derived Carbons for Ammonia Filtration.” 2015. Web. 26 Feb 2020.
Vancouver:
Mangarella MC. Designed Carbide-derived Carbons for Ammonia Filtration. [Internet] [Doctoral dissertation]. Georgia Tech; 2015. [cited 2020 Feb 26].
Available from: http://hdl.handle.net/1853/56197.
Council of Science Editors:
Mangarella MC. Designed Carbide-derived Carbons for Ammonia Filtration. [Doctoral Dissertation]. Georgia Tech; 2015. Available from: http://hdl.handle.net/1853/56197
Georgia Tech
17.
Choi, Dalsu.
Controlled Assembly of Semiconducting Polymers: From fundamental understanding towards stretchable electronics.
Degree: PhD, Chemical and Biomolecular Engineering, 2015, Georgia Tech
URL: http://hdl.handle.net/1853/56219
► Starting from first-time demonstration of controlled assembly of Poly(3-hexylthiophene) (P3HT), a model conjugated polymer, into mesoscale rod-like features, mechanistic elucidation of mesoscale molecular assembly process…
(more)
▼ Starting from first-time demonstration of controlled assembly of Poly(3-hexylthiophene) (P3HT), a model conjugated polymer, into mesoscale rod-like features, mechanistic elucidation of mesoscale molecular assembly process of P3HT could be proposed. Application of simple 2-step crystallization model successfully elaborated assembly process of P3HT molecules. We believe that understanding of the conjugated polymer assembly process obtained in this study using P3HT can be expanded to other conjugated molecule-solvent systems so that molecular assembly through solution processing methods can be applied in a more systematic and controllable manner.
Further, through systematic interrogation of P3HT films with varied degrees of molecular ordering prepared by controlling assembly of P3HT molecules, an inverse relationship between mechanical resiliency and charge carrier mobility/molecular ordering in conjugated polymer systems was determined definitively. As a solution to the dilemma, a simple elastomer blend approach incorporating the advantages of polymer molecular interactions and crystallization mechanisms was presented. A composite of processed P3HT and Polydimethylsiloxane (PDMS) was shown to create a semiconducting film exhibiting both high ductility and superior mobility versus single component organic semiconductor counterpart.
Advisors/Committee Members: Reichmanis, Elsa (advisor), Koros, William J. (committee member), Hess, Dennis W. (committee member), Meredith, J. Carson (committee member), Graham, Samuel (committee member).
Subjects/Keywords: Conjugated Polymer; Polymer Crystallization; Composite Materials
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APA ·
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APA (6th Edition):
Choi, D. (2015). Controlled Assembly of Semiconducting Polymers: From fundamental understanding towards stretchable electronics. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/56219
Chicago Manual of Style (16th Edition):
Choi, Dalsu. “Controlled Assembly of Semiconducting Polymers: From fundamental understanding towards stretchable electronics.” 2015. Doctoral Dissertation, Georgia Tech. Accessed February 26, 2020.
http://hdl.handle.net/1853/56219.
MLA Handbook (7th Edition):
Choi, Dalsu. “Controlled Assembly of Semiconducting Polymers: From fundamental understanding towards stretchable electronics.” 2015. Web. 26 Feb 2020.
Vancouver:
Choi D. Controlled Assembly of Semiconducting Polymers: From fundamental understanding towards stretchable electronics. [Internet] [Doctoral dissertation]. Georgia Tech; 2015. [cited 2020 Feb 26].
Available from: http://hdl.handle.net/1853/56219.
Council of Science Editors:
Choi D. Controlled Assembly of Semiconducting Polymers: From fundamental understanding towards stretchable electronics. [Doctoral Dissertation]. Georgia Tech; 2015. Available from: http://hdl.handle.net/1853/56219
Georgia Tech
18.
Abu-Hakmeh, Khaldoon E.
Computational study of polymer membranes for proton and anion exchange membranes fuel cells.
Degree: PhD, Chemical and Biomolecular Engineering, 2016, Georgia Tech
URL: http://hdl.handle.net/1853/56298
► Polymer electrolyte membranes with novel molecular architectures were simulated to study their structure-property relationships. Two types of polymer electrolyte membranes were considered: proton and anion…
(more)
▼ Polymer electrolyte membranes with novel molecular architectures were simulated to study their structure-property relationships. Two types of polymer electrolyte membranes were considered: proton and anion exchange membranes. As a benchmark, Nafion, the most commercially successful membrane material, was simulated and subjected to mechanical deformation. The resulting water phase was found to be better developed in the direction perpendicular to deformation than in the stretched direction. Next, alternative hydrocarbon-based proton exchange membranes were designed and simulated. Polysulfone based membranes with typically exhibited smaller water domain sizes compared to Nafion. However, membranes with larger side chains and high sulfonation exhibited phase separation and transport properties comparable to Nafion. A polysulfone-based anion exchange membrane was compared to a proton exchange membrane with the same backbone. The two membranes exhibited similar phase-segregated morphologies, with significantly lower ionic transport in the anion exchange model. Last, a series of highly fluorinated multi-block copolymer anion exchange membrane were simulated and characterized. The simulations were validated by experimental structure and transport property trends. Design parameters to improve membrane performance and implications for future research are discussed.
Advisors/Committee Members: Jang, Seung Soon (advisor), Fuller, Thomas (advisor), Koros, William (committee member), Kohl, Paul (committee member), Ludovice, Peter (committee member).
Subjects/Keywords: Molecular dynamics; Fuel cells; Proton exchange membranes; Anion exchange membranes
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APA (6th Edition):
Abu-Hakmeh, K. E. (2016). Computational study of polymer membranes for proton and anion exchange membranes fuel cells. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/56298
Chicago Manual of Style (16th Edition):
Abu-Hakmeh, Khaldoon E. “Computational study of polymer membranes for proton and anion exchange membranes fuel cells.” 2016. Doctoral Dissertation, Georgia Tech. Accessed February 26, 2020.
http://hdl.handle.net/1853/56298.
MLA Handbook (7th Edition):
Abu-Hakmeh, Khaldoon E. “Computational study of polymer membranes for proton and anion exchange membranes fuel cells.” 2016. Web. 26 Feb 2020.
Vancouver:
Abu-Hakmeh KE. Computational study of polymer membranes for proton and anion exchange membranes fuel cells. [Internet] [Doctoral dissertation]. Georgia Tech; 2016. [cited 2020 Feb 26].
Available from: http://hdl.handle.net/1853/56298.
Council of Science Editors:
Abu-Hakmeh KE. Computational study of polymer membranes for proton and anion exchange membranes fuel cells. [Doctoral Dissertation]. Georgia Tech; 2016. Available from: http://hdl.handle.net/1853/56298
Georgia Tech
19.
Pahinkar, Darshan Gopalrao.
Temperature swing adsorption processes for gas separation.
Degree: PhD, Mechanical Engineering, 2016, Georgia Tech
URL: http://hdl.handle.net/1853/56348
► Natural gas has become increasingly important as a fuel source with lower environmental impact; therefore, there is a growing need for scalable natural gas purification…
(more)
▼ Natural gas has become increasingly important as a fuel source with lower environmental impact; therefore, there is a growing need for scalable natural gas purification systems with small footprints. Current industrial purification systems are based on absorption, membrane separation, or adsorption techniques; however, each of these technologies requires large capital costs or suffers from scalability issues. Adsorption-based separation techniques are categorized into pressure-swing adsorption (PSA) and temperature-swing adsorption (TSA). Among adsorption-based gas purification techniques, PSA has typically been preferred over TSA due to the ease of operation and reliability. TSA processes have not commonly been used for industrial gas separation due to low thermal conductivity of the adsorbent bed, which causes difficulty in desorbing impurities and regenerating the adsorbent. However, the high heat and mass transfer coefficients possible with microchannels open the possibility of using the TSA process for gas purification.
This work investigated the fluid mechanics and coupled heat and mass transfer processes within a microchannel monolith with a polymer-adsorbent matrix coating the inner walls of the microchannels during TSA-based gas separation. The concept involved separation of carbon dioxide from methane by passing the feed gas through microchannels, followed by sequential flow of desorbing hot liquid, cooling liquid, and purge gas through the same microchannels. It was found that for selected operating conditions and geometries, the process showed merit when compared to current technologies. A combination of spatially- and temporally-resolved analyses was conducted to assess these processes and select optimal configurations and process parameters. Experimental validation followed, wherein the adsorption stage of the separation process in adsorbent-coated microchannels was measured and analyzed using mass spectrometry. The combination of measurements and analyses was used to develop validated models and provide design guidance for TSA processes.
Advisors/Committee Members: Garimella, Srinivas (advisor), Graham, Samuel (committee member), Kumar, Satish (committee member), Jeter, Sheldon (committee member), Koros, William (committee member).
Subjects/Keywords: Temperature swing adsorption; Microchannels; Natural gas purification; Gas separation
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APA (6th Edition):
Pahinkar, D. G. (2016). Temperature swing adsorption processes for gas separation. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/56348
Chicago Manual of Style (16th Edition):
Pahinkar, Darshan Gopalrao. “Temperature swing adsorption processes for gas separation.” 2016. Doctoral Dissertation, Georgia Tech. Accessed February 26, 2020.
http://hdl.handle.net/1853/56348.
MLA Handbook (7th Edition):
Pahinkar, Darshan Gopalrao. “Temperature swing adsorption processes for gas separation.” 2016. Web. 26 Feb 2020.
Vancouver:
Pahinkar DG. Temperature swing adsorption processes for gas separation. [Internet] [Doctoral dissertation]. Georgia Tech; 2016. [cited 2020 Feb 26].
Available from: http://hdl.handle.net/1853/56348.
Council of Science Editors:
Pahinkar DG. Temperature swing adsorption processes for gas separation. [Doctoral Dissertation]. Georgia Tech; 2016. Available from: http://hdl.handle.net/1853/56348
Georgia Tech
20.
Demir, Hakan.
Computational exploration of thermodynamic properties of porous and layered materials.
Degree: PhD, Chemical and Biomolecular Engineering, 2016, Georgia Tech
URL: http://hdl.handle.net/1853/58570
► In this thesis, ab-initio based force fields were developed for Ar and Xe adsorption in six different MOFs to predict adsorption properties and compare this…
(more)
▼ In this thesis, ab-initio based force fields were developed for Ar and Xe adsorption in six different MOFs to predict adsorption properties and compare this non-empirical approach to the experimental results and generic force field (FF) simulations. Using three DFT functionals (PBE-D2, vdW-DF, and vdW-DF2) in periodic models of M-MOF-74 (M= Co, Ni, Zn, Mg), ZIF-8 and Cu-BTC, first principles based FFs are derived. Selective separation of contaminants from ambient air is another crucial field since some of those contaminants can be detrimental to health. Moreover, UiO-66 is computationally functionalized with more than 30 functional groups using cluster and periodic systems and binding energies of NH3, H2S, CO2 and H2O are calculated to rank the functionalized UiO-66 materials for selective separation of contaminants in humid air conditions. Finally, the phase stability and transitions of 2-D layered ferroelectric materials, CuInP2Q6 (Q=S, Se), are investigated. The phase transition of CuInP2Se6 is studied using DFT calculations and phonon theory to identify instabilities at zone center and boundaries of the structure while possible spinodal decomposition regions of CuxInyP2S6 are determined with respect to Cu concentration by combining DFT calculations with thermodynamic relations.
Advisors/Committee Members: Walton, Krista S. (committee member), Koros, William J. (committee member), Jones, Christopher W. (committee member), Jang, Seung Soon (committee member).
Subjects/Keywords: Metal-organic framework; Gas adsorption; Ferroelectric material; Phase stability
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APA (6th Edition):
Demir, H. (2016). Computational exploration of thermodynamic properties of porous and layered materials. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/58570
Chicago Manual of Style (16th Edition):
Demir, Hakan. “Computational exploration of thermodynamic properties of porous and layered materials.” 2016. Doctoral Dissertation, Georgia Tech. Accessed February 26, 2020.
http://hdl.handle.net/1853/58570.
MLA Handbook (7th Edition):
Demir, Hakan. “Computational exploration of thermodynamic properties of porous and layered materials.” 2016. Web. 26 Feb 2020.
Vancouver:
Demir H. Computational exploration of thermodynamic properties of porous and layered materials. [Internet] [Doctoral dissertation]. Georgia Tech; 2016. [cited 2020 Feb 26].
Available from: http://hdl.handle.net/1853/58570.
Council of Science Editors:
Demir H. Computational exploration of thermodynamic properties of porous and layered materials. [Doctoral Dissertation]. Georgia Tech; 2016. Available from: http://hdl.handle.net/1853/58570
Georgia Tech
21.
Kang, Dun-Yen.
Single-walled metal oxide nanotubes and nanotube membranes for molecular separations.
Degree: PhD, Chemical Engineering, 2012, Georgia Tech
URL: http://hdl.handle.net/1853/44715
► Synthetic single-walled metal oxide (aluminosilicate) nanotubes (SWNTs) are emerging materials for a number of applications involving molecular transport and adsorption due to their unique pore…
(more)
▼ Synthetic single-walled metal oxide (aluminosilicate) nanotubes (SWNTs) are emerging materials for a number of applications involving molecular transport and adsorption due to their unique pore structure, high surface reactivity, and controllable dimensions. In this thesis, I discuss the potential for employing SWNTs in next generation separation platforms based upon recent progress on synthesis, interior modification, molecular diffusion properties, transport modeling and composite membrane preparation of metal oxide SWNTs. First, I describe the structure, synthesis, and characterization of the SWNTs. Thereafter, chemical modification of the nanotube interior is described as a means for tuning the nanotube properties for molecular separations. Interior functionalization of SWNTs (e.g. carbon nanotubes and metal oxide nanotubes) is a long-standing challenge in nanomaterials science. After controlled dehydration and dehydroxylation of the SWNTs, I then demonstrate that the SWNT inner surface can be functionalized with various organic groups of practical interest via solid-liquid heterogeneous reactions. Finally, I describe a mass transport modeling and measurements for composite membranes composed of SWNTs as fillers. This work demonstrates the use of SWNTs for novel scalable separation units from both a nanoscale and a macroscale point of view.
Advisors/Committee Members: Nair, Sankar (Committee Chair), Jones, Christopher (Committee Co-Chair), Beckham, Haskell (Committee Member), Koros, William (Committee Member), Sholl, David (Committee Member).
Subjects/Keywords: Nanomaterial; Membrane separation; Nanotube; Nanostructured materials; Nanotubes; Nanotechnology; Separation (Technology); Nanofiltration
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APA (6th Edition):
Kang, D. (2012). Single-walled metal oxide nanotubes and nanotube membranes for molecular separations. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/44715
Chicago Manual of Style (16th Edition):
Kang, Dun-Yen. “Single-walled metal oxide nanotubes and nanotube membranes for molecular separations.” 2012. Doctoral Dissertation, Georgia Tech. Accessed February 26, 2020.
http://hdl.handle.net/1853/44715.
MLA Handbook (7th Edition):
Kang, Dun-Yen. “Single-walled metal oxide nanotubes and nanotube membranes for molecular separations.” 2012. Web. 26 Feb 2020.
Vancouver:
Kang D. Single-walled metal oxide nanotubes and nanotube membranes for molecular separations. [Internet] [Doctoral dissertation]. Georgia Tech; 2012. [cited 2020 Feb 26].
Available from: http://hdl.handle.net/1853/44715.
Council of Science Editors:
Kang D. Single-walled metal oxide nanotubes and nanotube membranes for molecular separations. [Doctoral Dissertation]. Georgia Tech; 2012. Available from: http://hdl.handle.net/1853/44715
Georgia Tech
22.
Kang, Ji-Hwan.
Triplet fusion photon upconversion systems: Towards low threshold applications.
Degree: PhD, Chemical and Biomolecular Engineering, 2017, Georgia Tech
URL: http://hdl.handle.net/1853/59766
► Photon upconversion (UC), a promising anti-Stokes process that can convert two or more photons with low energy to a single photon of higher energy, can…
(more)
▼ Photon upconversion (UC), a promising anti-Stokes process that can convert two or more photons with low energy to a single photon of higher energy, can be readily achieved via triplet fusion or triplet-triplet annihilation (TTA) using low incident power density. To facilitate energy migration required for TTA-based upconversion systems, triplet exciton diffusion of the chromophores within an inert medium is of paramount importance, especially for practical device integration. However, the majority of studies have been carried out where the conditions have limitations such as deoxygenated organic solvents and bulk polymer matrices. The research objective here, therefore, is to find effective ways to apply active UC materials into potential devices powered by sunlight. In this thesis, we will investigate how to improve the diffusion-limited energy transfer in TTA-UC processes and demonstrate diverse approaches to enhance their optical properties in terms of materials science and engineering perspectives. First, we will discuss two microfluidics-based approaches which allow for the controlled formation of uniform microcapsules that contain a chromophore-embedded solution core. One is photo-induced interfacial polymerization and the other is multiple emulsion encapsulation using coaxially focused glass capillaries. These core-shell structures provide high quantum yields due to the preservation of molecular mobility in the fluidic phase, as well as structural rigidity and photochemical stability. In addition, we will address alternative photon energy manipulating approaches using the tunable interference structure of cholesteric liquid crystals and surface plasmon resonance coupling of gold nanorods to increase TTA-UC emission intensities and tailor the resultant optical properties.
Advisors/Committee Members: Reichmanis, Elsa (advisor), Hess, Dennis W. (committee member), Koros, William J. (committee member), Behrens, Sven H. (committee member), Kippelen, Bernard J. (committee member).
Subjects/Keywords: Upconversion; Anti-stokes shift; Triplet-triplet annihilation; Energy transfer
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APA (6th Edition):
Kang, J. (2017). Triplet fusion photon upconversion systems: Towards low threshold applications. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/59766
Chicago Manual of Style (16th Edition):
Kang, Ji-Hwan. “Triplet fusion photon upconversion systems: Towards low threshold applications.” 2017. Doctoral Dissertation, Georgia Tech. Accessed February 26, 2020.
http://hdl.handle.net/1853/59766.
MLA Handbook (7th Edition):
Kang, Ji-Hwan. “Triplet fusion photon upconversion systems: Towards low threshold applications.” 2017. Web. 26 Feb 2020.
Vancouver:
Kang J. Triplet fusion photon upconversion systems: Towards low threshold applications. [Internet] [Doctoral dissertation]. Georgia Tech; 2017. [cited 2020 Feb 26].
Available from: http://hdl.handle.net/1853/59766.
Council of Science Editors:
Kang J. Triplet fusion photon upconversion systems: Towards low threshold applications. [Doctoral Dissertation]. Georgia Tech; 2017. Available from: http://hdl.handle.net/1853/59766
Georgia Tech
23.
Hoysall, Dhruv Chanakya.
Absorption of ammonia-water mixtures in microscale geometries for miniaturized absorption systems.
Degree: PhD, Mechanical Engineering, 2018, Georgia Tech
URL: http://hdl.handle.net/1853/59830
► Vapor absorption-based HVAC systems are attracting increased interest due to their capability to utilize low-grade waste-heat streams, and low global warming potential of the working…
(more)
▼ Vapor absorption-based HVAC systems are attracting increased interest due to their capability to utilize low-grade waste-heat streams, and low global warming potential of the working fluids. The performance of an absorption system depends significantly on the absorber, which absorbs the refrigerant vapor into the absorbent fluid. Components with microscale features to enhance heat and mass transfer have been shown to significantly reduce the size of absorption cooling systems, making them viable for small-scale applications, such as residential and mobile use. But an incomplete understanding of the internal flow phenomena in microscale absorbers is limiting those gains. Performance limiting factors for microscale absorbers are investigated. One of the key performance limiting factors is maldistribution of vapor and liquid phases in these microscale geometries. Air-water mixtures are used to represent two-phase flow through three different microscale geometries, namely, a microchannel array, a microchannel array with mixing sections, and a serpentine pin-fin test section. The flow distribution is visually tracked along the length of the microscale geometries. Statistical distributions of void fraction and interfacial area along the microchannel array are calculated. Parameters such as the average void fraction and interfacial area intensity are used to evaluate and compare the different microscale geometries. This study also investigates the internal flow phenomena in an absorber by visualizing the process of absorption and measuring local temperatures in microscale geometries. A single unit of a microscale absorber consisting of two heat exchange plates; one with an ammonia–water mixture, and the other with a coupling fluid to absorb the heat released during absorption, is fabricated. Heat and mass transfer mechanisms in the microscale components are investigated. An open absorption system was fabricated to evaluate the absorber, as it enables control over inlet properties of the fluids. Two microscale absorber designs are evaluated in the test facility. The effects of solution flow rate, solution nominal concentration, operating pressures, and coupling fluid temperature are evaluated. A model is developed to predict heat and mass transfer in these microscale absorbers. This study provides insight into the limiting factors of current designs, and improvements that can be made in the future designs of such components.
Advisors/Committee Members: Garimella, Srinivas (advisor), Kumar, Satish (committee member), Jeter, Sheldon (committee member), Koros, William (committee member), Sulchek, Todd (committee member).
Subjects/Keywords: Microscale heat and mass transfer; Vapor absorption cooling
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APA (6th Edition):
Hoysall, D. C. (2018). Absorption of ammonia-water mixtures in microscale geometries for miniaturized absorption systems. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/59830
Chicago Manual of Style (16th Edition):
Hoysall, Dhruv Chanakya. “Absorption of ammonia-water mixtures in microscale geometries for miniaturized absorption systems.” 2018. Doctoral Dissertation, Georgia Tech. Accessed February 26, 2020.
http://hdl.handle.net/1853/59830.
MLA Handbook (7th Edition):
Hoysall, Dhruv Chanakya. “Absorption of ammonia-water mixtures in microscale geometries for miniaturized absorption systems.” 2018. Web. 26 Feb 2020.
Vancouver:
Hoysall DC. Absorption of ammonia-water mixtures in microscale geometries for miniaturized absorption systems. [Internet] [Doctoral dissertation]. Georgia Tech; 2018. [cited 2020 Feb 26].
Available from: http://hdl.handle.net/1853/59830.
Council of Science Editors:
Hoysall DC. Absorption of ammonia-water mixtures in microscale geometries for miniaturized absorption systems. [Doctoral Dissertation]. Georgia Tech; 2018. Available from: http://hdl.handle.net/1853/59830
Georgia Tech
24.
Jiao, Yang.
Defect engineering and conversion of metal-organic frameworks for adsorption and electrical energy storage applications.
Degree: PhD, Chemical and Biomolecular Engineering, 2017, Georgia Tech
URL: http://hdl.handle.net/1853/60160
► Metal-organic frameworks (MOFs) are hybrid porous materials, constructed by the assembly of inorganic metal ions or clusters and organic ligands. MOFs have attracted considerable research…
(more)
▼ Metal-organic frameworks (MOFs) are hybrid porous materials, constructed by the assembly of inorganic metal ions or clusters and organic ligands. MOFs have attracted considerable research interest in the fields of gas adsorption and separations, owing to their high surface areas, permanent porosity, tailorable pore sizes, and remarkable tunability. Numerous modification strategies have been developed for engineering MOF crystals based on their desired characteristics. MOFs can have intentionally generated crystal imperfections by using defect engineering strategies during their synthesis. Defect engineering is an effective strategy that can be used to tune the physical and chemical features of MOFs such as their chemical stability, textural and adsorption properties. Understanding the impact of defects on the changes in these properties of MOFs is imperative to the development of next-generation defective MOFs. Chapters 3 and 4 provide detailed studies on two typical defect types (e.g. mixed-metal and missing cluster defects) that are commonly found in defective MOFs. In chapter 3, experimental investigations revealing trends related to the effect of mixed-metal centers on CO2 adsorption and water stability properties are addressed. Chapter 4 provides insight into the impact of missing cluster defects on chemical stability and adsorption properties through experimental and computational methods. Beyond being used as adsorbents, these hybrid crystals can also be converted to metal oxides, metal hydroxides and carbons via facile chemical treatments. These MOF-derived materials usually possess high surface areas, large pore volumes, diverse functional groups, controllable morphology, and hierarchical-pore architectures. These features make MOFs-as-templates strategies promising choices for electrical energy storage applications such as supercapacitors. Chapter 5 investigates the relationship between MOF stability and the cycling stability of MOF-derived electrode materials via complimentary experimental techniques. Chapter 6 evaluates the electrochemical performance of both positive and negative electrode materials that are synthesized from a single MOFs-reduced graphene oxide (rGO) precursor. In general, this dissertation explores the possibilities of defect engineering and MOFs-as-templates (MOF conversion) strategies that could be used to design and engineer MOFs or MOF-derived materials for adsorption and electrical energy storage applications.
Advisors/Committee Members: Walton, Krista (advisor), Sholl, David (committee member), Lively, Ryan (committee member), Koros, William (committee member), Liu, Meilin (committee member).
Subjects/Keywords: Metal-organic frameworks; Defect engineering; Chemical stability; Adsorption; Supercapacitors; MOF derivatives; Hydroxides; Porous carbon
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APA (6th Edition):
Jiao, Y. (2017). Defect engineering and conversion of metal-organic frameworks for adsorption and electrical energy storage applications. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/60160
Chicago Manual of Style (16th Edition):
Jiao, Yang. “Defect engineering and conversion of metal-organic frameworks for adsorption and electrical energy storage applications.” 2017. Doctoral Dissertation, Georgia Tech. Accessed February 26, 2020.
http://hdl.handle.net/1853/60160.
MLA Handbook (7th Edition):
Jiao, Yang. “Defect engineering and conversion of metal-organic frameworks for adsorption and electrical energy storage applications.” 2017. Web. 26 Feb 2020.
Vancouver:
Jiao Y. Defect engineering and conversion of metal-organic frameworks for adsorption and electrical energy storage applications. [Internet] [Doctoral dissertation]. Georgia Tech; 2017. [cited 2020 Feb 26].
Available from: http://hdl.handle.net/1853/60160.
Council of Science Editors:
Jiao Y. Defect engineering and conversion of metal-organic frameworks for adsorption and electrical energy storage applications. [Doctoral Dissertation]. Georgia Tech; 2017. Available from: http://hdl.handle.net/1853/60160
Georgia Tech
25.
Chu, Yu-Han.
Transition metal-containing carbon molecular sieve membranes for advanced olefin/paraffin separations.
Degree: PhD, Chemical and Biomolecular Engineering, 2017, Georgia Tech
URL: http://hdl.handle.net/1853/60165
► In this work, carbon molecular sieve (CMS) dense film membranes derived from 6FDA-DAM:DABA (3:2) polyimide precursor were studied for separation of mixed olefins (C2H4 and…
(more)
▼ In this work, carbon molecular sieve (CMS) dense film membranes derived from 6FDA-DAM:DABA (3:2) polyimide precursor were studied for separation of mixed olefins (C2H4 and C3H6) from paraffins (C2H6 and C3H8). Olefin-selective CMS membranes with high performance can be made by pyrolysis of metal-containing polymeric precursors. Pyrolyzed at 550°C with a fast ramp rate, CMS membranes with integrated Fe2+ (2.2 wt% in the precursor) showed 19% higher C2H4/C2H6 and 11% higher C3H6/C3H8 sorption selectivity than that of the neat CMS membrane. Additional investigations with a quaternary mixture feed (C2 and C3 hydrocarbons) show that C2H4 permeability above 10 Barrers with C2H4/C2H6 permselectivity near 11 were achieved for the 3.2 wt% Fe loading case. Although Fe incorporation did not appear to promote C3H6/C2H6 permselectivity, Fe is useful to achieve impressive C2 pair olefin/paraffin separation. Deconvolution of the C2H4/C2H6 permselectivity for the more extensively studied 2.2 wt% loading case was also revealing. While both sorption and diffusion selectivity increased due to the Fe incorporation, a larger influence is seen on the diffusion selectivity versus the sorption selectivity. This added diffusion selectivity was dominated by a contribution from an entropic factor with Fe, which is the feature for CMS materials to surpass conventional polymer membranes.
Advisors/Committee Members: Koros, William (advisor), Agrawal, Pradeep (committee member), Jones, Christopher (committee member), Bucknall, David (committee member), Brayden, Mark (committee member), Xu, Liren (committee member).
Subjects/Keywords: Carbon molecular sieve; Olefin/paraffin separation; Transition metal bearing membrane
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APA (6th Edition):
Chu, Y. (2017). Transition metal-containing carbon molecular sieve membranes for advanced olefin/paraffin separations. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/60165
Chicago Manual of Style (16th Edition):
Chu, Yu-Han. “Transition metal-containing carbon molecular sieve membranes for advanced olefin/paraffin separations.” 2017. Doctoral Dissertation, Georgia Tech. Accessed February 26, 2020.
http://hdl.handle.net/1853/60165.
MLA Handbook (7th Edition):
Chu, Yu-Han. “Transition metal-containing carbon molecular sieve membranes for advanced olefin/paraffin separations.” 2017. Web. 26 Feb 2020.
Vancouver:
Chu Y. Transition metal-containing carbon molecular sieve membranes for advanced olefin/paraffin separations. [Internet] [Doctoral dissertation]. Georgia Tech; 2017. [cited 2020 Feb 26].
Available from: http://hdl.handle.net/1853/60165.
Council of Science Editors:
Chu Y. Transition metal-containing carbon molecular sieve membranes for advanced olefin/paraffin separations. [Doctoral Dissertation]. Georgia Tech; 2017. Available from: http://hdl.handle.net/1853/60165
Georgia Tech
26.
Newalkar, Gautami.
High-pressure pyrolysis and gasification of biomass.
Degree: PhD, Chemical and Biomolecular Engineering, 2015, Georgia Tech
URL: http://hdl.handle.net/1853/53917
► With the limited reserves of fossil fuels and the environmental problems associated with their use, the world is moving towards cleaner, renewable, and sustainable sources…
(more)
▼ With the limited reserves of fossil fuels and the environmental problems associated with their use, the world is moving towards cleaner, renewable, and sustainable sources of energy. Biomass is a promising feedstock towards attaining this goal because it is abundant, renewable, and can be considered as a carbon neutral source of energy. Syngas can be further processed to produce liquid fuels, hydrogen, high value chemicals, or it can be converted to heat and power using turbines. Most of the downstream processing of syngas occurs at high pressures, which requires cost intensive gas compression. It has been considered to be techno-economically advantageous to generate pressurized syngas by performing high-pressure gasification.
Gasification utilizes high temperatures and an oxidizing gas to convert biomass to synthesis gas (syngas, a mixture of CO and H2). Most of the past studies on gasification used process conditions that did not simulate an industrial gasification operation. This work aims at understanding the chemical and physical transformations taking place during high-pressure biomass gasification at heating rates of practical significance. We have adopted an approach of breaking down the gasification process into two steps: 1) Pyrolysis or devolatalization (fast step), and 2) Char gasification (slow step). This approach allows us to understand pyrolysis and char gasification separately and also to study the effect of pyrolysis conditions on the char gasification kinetics. Alkali and alkaline earth metals in biomass are known to catalyze the gasification reaction. This potentially makes biomass feedstock a cheap source of catalyst during coal gasification. This work also explores catalytic interactions in biomass-coal blends during co-gasification of the mixed feeds. The results of this study can be divided into four parts: (a) pyrolysis of loblolly pine; (b) gasification of pine chars; (c) pyrolysis and gasification of switchgrass; (d) co-gasification of pine/switchgrass with lignite and bituminous coals.
Advisors/Committee Members: Sievers, Carsten (advisor), Agrawal, Pradeep K. (advisor), Seitzman, Jerry (committee member), Sinquefield, Scott (committee member), Iisa, Kristiina (committee member), Koros, William J. (committee member).
Subjects/Keywords: Biomass; Pyrolysis; Gasification; Co-gasification; Coal; Renewable energy
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APA (6th Edition):
Newalkar, G. (2015). High-pressure pyrolysis and gasification of biomass. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/53917
Chicago Manual of Style (16th Edition):
Newalkar, Gautami. “High-pressure pyrolysis and gasification of biomass.” 2015. Doctoral Dissertation, Georgia Tech. Accessed February 26, 2020.
http://hdl.handle.net/1853/53917.
MLA Handbook (7th Edition):
Newalkar, Gautami. “High-pressure pyrolysis and gasification of biomass.” 2015. Web. 26 Feb 2020.
Vancouver:
Newalkar G. High-pressure pyrolysis and gasification of biomass. [Internet] [Doctoral dissertation]. Georgia Tech; 2015. [cited 2020 Feb 26].
Available from: http://hdl.handle.net/1853/53917.
Council of Science Editors:
Newalkar G. High-pressure pyrolysis and gasification of biomass. [Doctoral Dissertation]. Georgia Tech; 2015. Available from: http://hdl.handle.net/1853/53917
Georgia Tech
27.
Jasuja, Himanshu.
Developing design criteria and scale up methods for water-stable metal-organic frameworks for adsorption applications.
Degree: PhD, Chemical and Biomolecular Engineering, 2014, Georgia Tech
URL: http://hdl.handle.net/1853/54001
► Metal-organic frameworks (MOFs) are a relatively new class of porous materials, assembled from inorganic metal nodes and organic ligands. MOFs have garnered significant attention in…
(more)
▼ Metal-organic frameworks (MOFs) are a relatively new class of porous materials, assembled from inorganic metal nodes and organic ligands. MOFs have garnered significant attention in the porous materials and adsorption fields in recent years due to their various attractive features such as high surface areas and pore volumes, tunable and uniform pore sizes, chemically functionalized adsorption sites, and potential for post-synthetic modification. These features give MOFs enormous potential for use in applications such as air purification, methane and hydrogen storage, separations, catalysis, sensing, and drug delivery. Therefore, synthesis and adsorption studies of MOFs have increased tremendously in recent years. Among the aforesaid applications, air purification and air quality control are important topics because existing porous media are ineffective at the adsorptive removal of toxic industrial chemicals (TICs) and chemical warfare agents. Thus, there is a critical need for radical improvements in these purification systems. MOFs have shown great potential to become next-generation filter media as they outperform the traditional porous materials such as activated carbons and zeolites in the air purification of TICs such as ammonia and sulfur dioxide.
In spite of the numerous desirable attributes of MOFs, the practical use of these new materials in most applications hinges on their stability in humid or aqueous environments. The sensitivity of certain MOFs under humid conditions is well known, but systematic studies of the water stability properties of MOFs are lacking. This information is critical for identifying structural factors that are important for development of next-generation, water stable MOFs. In addition to the water stability issue, difficulty in the scale up of MOF synthesis has also plagued MOFs. Hence, the goal of this Ph.D. dissertation research is to design ammonia-selective, water stable MOFs that can be synthesized on a large scale. This work will have a direct impact on moving the MOF field forward to the commercial level. To achieve the aforementioned goal, this Ph.D. dissertation research has been divided into following three objectives:
(1) Advance our understanding of the water stability of MOFs and develop design criteria for the construction of water stable MOFs.
(2) Design water stable, ammonia-selective MOFs for next-generation chemical, biological, radiological, and nuclear (CBRN) filter media.
(3) Investigate the scale-up of the UiO-66 MOF scaffold.
Through the research efforts over the past four years, it is discovered that it is possible to adjust the water stability of pillared MOFs in both positive and negative directions by proper shielding of the ligand via functional groups. This study is the first of its kind and is of high value for the MOF community. This shielding concept is further extended by synthesizing 4 novel isostructural MOFs with methyl functional groups at different positions on the ligand. For the first time, light is shed on the important distinction…
Advisors/Committee Members: Walton, Krista S. (advisor), Sholl, David S. (committee member), Koros, William J. (committee member), Meredith, Carson J. (committee member), Wilkinson, Angus P. (committee member).
Subjects/Keywords: Adsorption; Metal-organic frameworks (MOFs); Water stability; Ammonia filtration; Scale-up
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APA (6th Edition):
Jasuja, H. (2014). Developing design criteria and scale up methods for water-stable metal-organic frameworks for adsorption applications. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/54001
Chicago Manual of Style (16th Edition):
Jasuja, Himanshu. “Developing design criteria and scale up methods for water-stable metal-organic frameworks for adsorption applications.” 2014. Doctoral Dissertation, Georgia Tech. Accessed February 26, 2020.
http://hdl.handle.net/1853/54001.
MLA Handbook (7th Edition):
Jasuja, Himanshu. “Developing design criteria and scale up methods for water-stable metal-organic frameworks for adsorption applications.” 2014. Web. 26 Feb 2020.
Vancouver:
Jasuja H. Developing design criteria and scale up methods for water-stable metal-organic frameworks for adsorption applications. [Internet] [Doctoral dissertation]. Georgia Tech; 2014. [cited 2020 Feb 26].
Available from: http://hdl.handle.net/1853/54001.
Council of Science Editors:
Jasuja H. Developing design criteria and scale up methods for water-stable metal-organic frameworks for adsorption applications. [Doctoral Dissertation]. Georgia Tech; 2014. Available from: http://hdl.handle.net/1853/54001
Georgia Tech
28.
Burgess, Steven K.
Fundamentals of transport in poly(ethylene terephthalate) and poly(ethylene furanoate) barrier materials.
Degree: PhD, Chemical and Biomolecular Engineering, 2015, Georgia Tech
URL: http://hdl.handle.net/1853/54887
► The increasing use of polymeric materials in food packaging applications is due to many factors; however, most are related to cost. While poly(ethylene terephthalate) (PET)…
(more)
▼ The increasing use of polymeric materials in food packaging applications is due to many factors; however, most are related to cost. While poly(ethylene terephthalate) (PET) is currently the industry standard for soft-drink bottles, more stringent requirements on the barrier properties to oxygen are needed for PET to expand further into more demanding markets (i.e., juice, etc). The current work examines the fundamental oxygen and carbon dioxide permeation and sorption properties of amorphous, caffeine antiplasticized PET and amorphous poly(ethylene furanoate) (PEF), which is a new biologically sourced polyester that exhibits significantly enhanced performance compared to petroleum-sourced PET. The fundamental transport data reported herein at 35°C illustrate that amorphous PEF exhibits significant reductions in permeability for oxygen (11X), carbon dioxide (19X), and water (2X) compared to amorphous PET. Such impressive barrier enhancements are unexpected since PEF exhibits a higher free volume compared to PET. Further investigation into the fundamental chain motional processes which contribute to penetrant diffusion, as probed via dynamic mechanical and solid-state NMR methods, reveals that the polymer ring-flipping motions in PEF are largely suppressed compared to those for PET. Such behavior allows for rationalization of the reduced transport properties compared to PET. Additional characterization techniques (i.e., thermal, mechanical, density, etc.) are used to develop a more complete understanding of PEF and caffeine antiplasticized PET, with the ultimate goal of relating these properties to penetrant transport.
Advisors/Committee Members: Koros, William J. (advisor), Fuller, Thomas F. (committee member), Sholl, David S. (committee member), Kriegel, Robert M. (committee member), Beckham, Haskell W. (committee member).
Subjects/Keywords: Barriers; PET; Poly(ethylene terephthalate); PEF; Poly(ethylene furanoate); Transport; Oxygen; Carbon dioxide; Water; Transport energetics; Antiplasticization; Blend; Copolymer; Caffeine
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APA (6th Edition):
Burgess, S. K. (2015). Fundamentals of transport in poly(ethylene terephthalate) and poly(ethylene furanoate) barrier materials. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/54887
Chicago Manual of Style (16th Edition):
Burgess, Steven K. “Fundamentals of transport in poly(ethylene terephthalate) and poly(ethylene furanoate) barrier materials.” 2015. Doctoral Dissertation, Georgia Tech. Accessed February 26, 2020.
http://hdl.handle.net/1853/54887.
MLA Handbook (7th Edition):
Burgess, Steven K. “Fundamentals of transport in poly(ethylene terephthalate) and poly(ethylene furanoate) barrier materials.” 2015. Web. 26 Feb 2020.
Vancouver:
Burgess SK. Fundamentals of transport in poly(ethylene terephthalate) and poly(ethylene furanoate) barrier materials. [Internet] [Doctoral dissertation]. Georgia Tech; 2015. [cited 2020 Feb 26].
Available from: http://hdl.handle.net/1853/54887.
Council of Science Editors:
Burgess SK. Fundamentals of transport in poly(ethylene terephthalate) and poly(ethylene furanoate) barrier materials. [Doctoral Dissertation]. Georgia Tech; 2015. Available from: http://hdl.handle.net/1853/54887
Georgia Tech
29.
Awati, Rohan Vivek.
Development of accurate computational methods for simulations of adsorption and diffusion in zeolites.
Degree: PhD, Chemical and Biomolecular Engineering, 2016, Georgia Tech
URL: http://hdl.handle.net/1853/54945
► The overall objective of this thesis has been to develop accurate computational methods for the diffusion and adsorption of small gases in zeolites. Firstly, the…
(more)
▼ The overall objective of this thesis has been to develop accurate computational methods for the diffusion and adsorption of small gases in zeolites. Firstly, the effect of the zeolite framework flexiblity on the single component and binary diffusion of various gases were discussed. Results indicate that for tight fitting molecules the rigid framework approximation can produce order(s) of magnitude difference in diffusivities as compared to the simulations performed with a fully flexible framework. We proposed two simple methods in which the flexible structure of a zeolite is approximated as a set of discrete rigid snapshots. Both methods are orders of magnitude more efficient than the simulations with the fully flexible structure. Secondly, we use a combined classical and quantum chemistry based approach to systematically develop the force fields based on DFT calculations for interactions of simple molecules like CH4, N2, linear alkanes, and linear alkenes in zeolites. We used a higher level of theory known as the DFT/CC method to correct DFT energies that were used in the periodic DFT calculations to develop force fields. Our results show that DFT-derived force fields give good predictions of macroscopic properties like adsorption isotherms in zeolites. The force fields are transferrable across zeolites and hence can be further used to screen materials for different storage and separation applications.
Advisors/Committee Members: Sholl, David S. (committee member), Koros, William J. (committee member), Nair, Sankar (committee member), Walton, Krista S. (committee member), Jang, Seung Soon (committee member).
Subjects/Keywords: Molecular simulations; Force field; Flexible framework
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APA ·
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APA (6th Edition):
Awati, R. V. (2016). Development of accurate computational methods for simulations of adsorption and diffusion in zeolites. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/54945
Chicago Manual of Style (16th Edition):
Awati, Rohan Vivek. “Development of accurate computational methods for simulations of adsorption and diffusion in zeolites.” 2016. Doctoral Dissertation, Georgia Tech. Accessed February 26, 2020.
http://hdl.handle.net/1853/54945.
MLA Handbook (7th Edition):
Awati, Rohan Vivek. “Development of accurate computational methods for simulations of adsorption and diffusion in zeolites.” 2016. Web. 26 Feb 2020.
Vancouver:
Awati RV. Development of accurate computational methods for simulations of adsorption and diffusion in zeolites. [Internet] [Doctoral dissertation]. Georgia Tech; 2016. [cited 2020 Feb 26].
Available from: http://hdl.handle.net/1853/54945.
Council of Science Editors:
Awati RV. Development of accurate computational methods for simulations of adsorption and diffusion in zeolites. [Doctoral Dissertation]. Georgia Tech; 2016. Available from: http://hdl.handle.net/1853/54945
Georgia Tech
30.
Setzler, Brian Patrick.
Kinetic and transport modeling in proton exchange membrane fuel cells.
Degree: PhD, Chemical and Biomolecular Engineering, 2015, Georgia Tech
URL: http://hdl.handle.net/1853/55507
► The improvement of PEMFC performance and durability requires a quantitative understanding of the processes that cause performance losses. In this dissertation, two models are developed…
(more)
▼ The improvement of PEMFC performance and durability requires a quantitative understanding of the processes that cause performance losses. In this dissertation, two models are developed incorporating new processes that have been poorly described or neglected in previous literature sources (catalyst oxide layer, hardware effects, enhanced vapor diffusion, and interfacial saturation). In simulations of electrochemical impedance spectroscopy (EIS), the kinetic effect of the catalyst oxide layer is found to cause a large, low-frequency inductive loop in agreement with experiments. Accounting for the inductive loop unifies steady-state measurements of resistance with EIS measurements, solving a long-standing barrier to accurate interpretation of EIS. Furthermore, flooding losses due to two-phase water transport are one of the most poorly understood losses and are a major area for improvement. The addition of an interfacial saturation effect is found to provide the best explanation of flooding. Heat transfer is shown to be the controlling factor in the performance of PEMFCs under certain flooded conditions. The advancements of this dissertation in the modeling of the oxide layer and two-phase transport phenomena represent significant steps towards the goals of EIS analysis by physics-based model and a mathematical understanding of performance degradation due to carbon corrosion and flooding.
Advisors/Committee Members: Fuller, Thomas F. (advisor), Koros, William J. (committee member), Kohl, Paul A. (committee member), Henderson, Clifford L. (committee member), Alamgir, Faisal M. (committee member).
Subjects/Keywords: Proton exchange membrane fuel cell; Oxygen reduction reaction; Physics-based model; Electrochemical impedance spectroscopy; Two-phase transport; Fuel cell
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APA ·
Chicago ·
MLA ·
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CSE |
Export
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Manager
APA (6th Edition):
Setzler, B. P. (2015). Kinetic and transport modeling in proton exchange membrane fuel cells. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/55507
Chicago Manual of Style (16th Edition):
Setzler, Brian Patrick. “Kinetic and transport modeling in proton exchange membrane fuel cells.” 2015. Doctoral Dissertation, Georgia Tech. Accessed February 26, 2020.
http://hdl.handle.net/1853/55507.
MLA Handbook (7th Edition):
Setzler, Brian Patrick. “Kinetic and transport modeling in proton exchange membrane fuel cells.” 2015. Web. 26 Feb 2020.
Vancouver:
Setzler BP. Kinetic and transport modeling in proton exchange membrane fuel cells. [Internet] [Doctoral dissertation]. Georgia Tech; 2015. [cited 2020 Feb 26].
Available from: http://hdl.handle.net/1853/55507.
Council of Science Editors:
Setzler BP. Kinetic and transport modeling in proton exchange membrane fuel cells. [Doctoral Dissertation]. Georgia Tech; 2015. Available from: http://hdl.handle.net/1853/55507
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