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You searched for +publisher:"Georgia Tech" +contributor:("Dr. Charles A. Eckert"). Showing records 1 – 3 of 3 total matches.

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Georgia Tech

1. Janakat, Malina Elizabeth. Synergistic Approach to Exploration of the Microstructure of Novel, Tunable Solvents for Reactions, Separations and Catalyst Recycle.

Degree: PhD, Chemical Engineering, 2006, Georgia Tech

Gas-expanded liquids (GXLs) are a new and benign class of pressure-tunable liquid solvents which show tremendous promise as the next sustainable processing medium. In order to realize the potential of GXLs fully, it is necessary to elucidate their cybotactic region and gain an understanding of where properties are different in the bulk and micro-scales and how local structure and order affect both reactions and separations. This work explores the cybotactic region of GXLs and probes the existence and implications of those differences. This study is started by exploring the cybotactic region of ambient liquid mixtures. Thermodynamic models based on intermolecular forces are used to predict the solubility of multi-functional solids in a variety of solvent mixtures. While this part does not lend any insight into GXLs directly, it acts as a stepping stone in both understanding the intermolecular forces that govern the cybotactic region and by opening the gateway to studying solid solubility in GXLs. The rest of the study focuses on the differences between bulk and local properties of GXLs. Different probes of polarity in the cybotactic region are compared and the solute dependence of the local structure is explored. Bulk transport properties are measured with different probes in an effort to see if molecular interactions play a role in governing diffusion processes in GXLs. Advisors/Committee Members: Dr. Charles A. Eckert (Committee Chair), Dr. Charles L. Liotta (Committee Co-Chair), Dr. Amyn Teja (Committee Member), Dr. Rigoberto Hernandez (Committee Member), Dr. William J. Koros (Committee Member).

Subjects/Keywords: Gas-expanded liquids; Cybotactic region

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APA (6th Edition):

Janakat, M. E. (2006). Synergistic Approach to Exploration of the Microstructure of Novel, Tunable Solvents for Reactions, Separations and Catalyst Recycle. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/10461

Chicago Manual of Style (16th Edition):

Janakat, Malina Elizabeth. “Synergistic Approach to Exploration of the Microstructure of Novel, Tunable Solvents for Reactions, Separations and Catalyst Recycle.” 2006. Doctoral Dissertation, Georgia Tech. Accessed February 25, 2021. http://hdl.handle.net/1853/10461.

MLA Handbook (7th Edition):

Janakat, Malina Elizabeth. “Synergistic Approach to Exploration of the Microstructure of Novel, Tunable Solvents for Reactions, Separations and Catalyst Recycle.” 2006. Web. 25 Feb 2021.

Vancouver:

Janakat ME. Synergistic Approach to Exploration of the Microstructure of Novel, Tunable Solvents for Reactions, Separations and Catalyst Recycle. [Internet] [Doctoral dissertation]. Georgia Tech; 2006. [cited 2021 Feb 25]. Available from: http://hdl.handle.net/1853/10461.

Council of Science Editors:

Janakat ME. Synergistic Approach to Exploration of the Microstructure of Novel, Tunable Solvents for Reactions, Separations and Catalyst Recycle. [Doctoral Dissertation]. Georgia Tech; 2006. Available from: http://hdl.handle.net/1853/10461


Georgia Tech

2. Myneni, Satyanarayana. Post Plasma Etch Residue Removal Using Carbon Dioxide Based Fluids.

Degree: PhD, Chemical Engineering, 2004, Georgia Tech

As feature sizes in semiconductor devices become smaller and newer materials are incorporated, current methods for photoresist and post plasma etch residue removal face several challenges. A cleaning process should be environmentally benign, compatible with dielectric materials and copper, and provide residue removal from narrow and high aspect ratio features. In this work, sub-critical CO2 based mixtures have been developed to remove the etch residues; these mixtures satisfy the above requirements and can potentially replace the two step residue removal process currently used in the integrated circuit (IC) industry. Based on the chemical nature of the residue being removed, additives or co-solvents to CO2 have been identified that can remove the residues without damaging the dielectric layers. Using the phase behavior of these additives as a guide, the composition of the co-solvent was altered to achieve a single liquid phase at moderate pressures without compromising cleaning ability. The extent of residue removal has been analyzed primarily by x-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). Various techniques such as attenuated total reflection - Fourier transform infrared (ATR-FTIR) spectroscopy, angle-resolved XPS (ARXPS), and interferometry were used to probe the interaction of cleaning fluids with residues. Model films of photoresists and plasma deposited residues were used to assist in understanding the mechanism of residue removal. From these studies, it was concluded that residue removal takes place primarily by attack of the interface between the residue and the substrate; a solvent rinse then lifts these residues from the wafer. It has been shown that transport of the additives to the interface is enhanced in the presence of CO2. From positronium annihilation lifetime spectroscopy (PALS) studies on a porous dielectric film, it has been shown that these high pressure fluids do not cause significant changes to the pore sizes or the bonding structure of the film. Hence, this method can be used to remove post etch residues from low-k dielectric films. Advisors/Committee Members: Dr. Dennis W. Hess (Committee Chair), Dr. Amyn S. Teja (Committee Member), Dr. Charles A. Eckert (Committee Member), Dr. Charles L. Liotta (Committee Member), Dr. J. Carson Meredith (Committee Member).

Subjects/Keywords: Low-K; Angle resolved XPS; Surface cleaning; Supercritical carbon dioxide; ATR-FTIR; Fluorocarbon residue; Etch residue; Semiconductors Cleaning; Plasma etching; Liquid carbon dioxide Industrial applications

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APA (6th Edition):

Myneni, S. (2004). Post Plasma Etch Residue Removal Using Carbon Dioxide Based Fluids. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/7605

Chicago Manual of Style (16th Edition):

Myneni, Satyanarayana. “Post Plasma Etch Residue Removal Using Carbon Dioxide Based Fluids.” 2004. Doctoral Dissertation, Georgia Tech. Accessed February 25, 2021. http://hdl.handle.net/1853/7605.

MLA Handbook (7th Edition):

Myneni, Satyanarayana. “Post Plasma Etch Residue Removal Using Carbon Dioxide Based Fluids.” 2004. Web. 25 Feb 2021.

Vancouver:

Myneni S. Post Plasma Etch Residue Removal Using Carbon Dioxide Based Fluids. [Internet] [Doctoral dissertation]. Georgia Tech; 2004. [cited 2021 Feb 25]. Available from: http://hdl.handle.net/1853/7605.

Council of Science Editors:

Myneni S. Post Plasma Etch Residue Removal Using Carbon Dioxide Based Fluids. [Doctoral Dissertation]. Georgia Tech; 2004. Available from: http://hdl.handle.net/1853/7605


Georgia Tech

3. Marla, Krishna Tej. Molecular Thermodynamics of Nanoscale Colloid-Polymer Mixtures: Chemical Potentials and Interaction Forces.

Degree: PhD, Chemical Engineering, 2004, Georgia Tech

Nanoscale colloidal particles display fascinating electronic, optical and reinforcement properties as a consequence of their dimensions. Stable dispersions of nanoscale colloids find applications in drug delivery, biodiagnostics, photonic and electronic devices, and polymer nanocomposites. Most nanoparticles are unstable in dispersions and polymeric surfactants are added generally to improve dispersability and control self-assembly. However, the effect of polymeric modifiers on nanocolloid properties is poorly understood and design of modifiers is guided usually by empirical approaches. Monte Carlo simulations are used to gain a fundamental molecular-level understanding of the effect of modifiers properties on the thermodynamics and interaction forces of nanoscale colloidal particles. A novel method based on the expanded ensemble Monte Carlo technique has been developed for calculation of the chemical potential of colloidal particles in colloid-polymer mixtures (CPM). Using this method, the effect of molecular parameters like colloid diameter, polymer chain length, colloid-polymer interaction strength, and colloid and polymer concentrations, on the colloid chemical potential is investigated for both hard-sphere and attractive Lennard-Jones CPM. The presence of short-chain polymeric modifiers reduces the colloid chemical potential in attractive as well as athermal systems. In attractive CPM, there is a strong correlation between polymer adsorption and colloid chemical potential, as both show a similar dependence on the polymer molecular weight. Based on the simulation results, simple scaling relationships are proposed that capture the functional dependence of the thermodynamic properties on the molecular parameters. The polymer-induced interaction forces between the nanoparticles have been calculated as a function of the above parameters for freely-adsorbing and end-grafted homopolymer modifiers. The polymer-induced force profiles are used to identify design criteria for effective modifiers. Adsorbing modifiers give rise to attractive interactions between the nanoparticles over the whole parameter range explored in this study. Grafted surface modifiers lead to attraction or repulsion based on the polymer chain length and grafting density. The polymer-induced attraction in both adsorbing and grafted modifiers is attributed primarily to polymer intersegmental interactions and bridging. The location of the thermodynamic minimum corresponding to the equilibrium particle spacing in nanoparticle-polymer mixtures can be controlled by tuning the modifier properties. Advisors/Committee Members: Dr. J. Carson Meredith (Committee Chair), Dr. Charles A. Eckert (Committee Member), Dr. Clifford L. Henderson (Committee Member), Dr. Peter J. Ludovice (Committee Member), Dr. Rigoberto Hernandez (Committee Member).

Subjects/Keywords: Nanoparticle interaction forces; Colloid chemical potential; Nanoparticle-polymer systems; Colloid-polymer mixtures

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

APA (6th Edition):

Marla, K. T. (2004). Molecular Thermodynamics of Nanoscale Colloid-Polymer Mixtures: Chemical Potentials and Interaction Forces. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/7604

Chicago Manual of Style (16th Edition):

Marla, Krishna Tej. “Molecular Thermodynamics of Nanoscale Colloid-Polymer Mixtures: Chemical Potentials and Interaction Forces.” 2004. Doctoral Dissertation, Georgia Tech. Accessed February 25, 2021. http://hdl.handle.net/1853/7604.

MLA Handbook (7th Edition):

Marla, Krishna Tej. “Molecular Thermodynamics of Nanoscale Colloid-Polymer Mixtures: Chemical Potentials and Interaction Forces.” 2004. Web. 25 Feb 2021.

Vancouver:

Marla KT. Molecular Thermodynamics of Nanoscale Colloid-Polymer Mixtures: Chemical Potentials and Interaction Forces. [Internet] [Doctoral dissertation]. Georgia Tech; 2004. [cited 2021 Feb 25]. Available from: http://hdl.handle.net/1853/7604.

Council of Science Editors:

Marla KT. Molecular Thermodynamics of Nanoscale Colloid-Polymer Mixtures: Chemical Potentials and Interaction Forces. [Doctoral Dissertation]. Georgia Tech; 2004. Available from: http://hdl.handle.net/1853/7604

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