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163 full-text articles. Page 4 of 7.

A Study Of Diblock Copolymer/Charged Particle Nanoporous Membranes; Morphology, Design And Transport Property Modeling, Bo Zhang 2015 University of Tennessee - Knoxville

A Study Of Diblock Copolymer/Charged Particle Nanoporous Membranes; Morphology, Design And Transport Property Modeling, Bo Zhang

Doctoral Dissertations

A combination of self-consistent field theory and density functional theory was used to examine the stable, 3-dimensional equilibrium morphologies formed by diblock copolymers with a neutral or charged nanoparticle attached either between the two blocks or at the end of copolymer. Particle size was varied between one and four tenths of the radius of gyration of the copolymer. Phase diagrams were constructed and analyzed in terms of thermodynamic diagrams to understand the molecular-level self-assembly processes with the aim of determining the appropriate morphologies used as nanoporous membranes, (i.e. the periodic, hexagonal arrays of cylinders wherein the particles would primarily ...


Characterizing Non-Zeolitic Pore Volume In Zeolite Membranes By Temperature-Programmed Desorption, Miao Yu, J. Falconer, R. Noble 2015 University of South Carolina - Columbia

Characterizing Non-Zeolitic Pore Volume In Zeolite Membranes By Temperature-Programmed Desorption, Miao Yu, J. Falconer, R. Noble

Miao Yu

No abstract provided.


2,2-Dimethylbutane Adsorption And Diffusion In Mfi Zeolite, Miao Yu, J. Wyss, R. Noble, J. Falconer 2015 University of South Carolina - Columbia

2,2-Dimethylbutane Adsorption And Diffusion In Mfi Zeolite, Miao Yu, J. Wyss, R. Noble, J. Falconer

Miao Yu

No abstract provided.


Ultrafiltration Membranes With Structure-Optimized Graphene-Oxide Coatings For Antifouling Oil/Water Separation, Y. Huang, H. Li, Lei Wang, Yali Qiao, Chuanbing Tang, Chanil Jung, Yeomin Yoon, S. Li, Miao Yu 2015 University of South Carolina - Columbia

Ultrafiltration Membranes With Structure-Optimized Graphene-Oxide Coatings For Antifouling Oil/Water Separation, Y. Huang, H. Li, Lei Wang, Yali Qiao, Chuanbing Tang, Chanil Jung, Yeomin Yoon, S. Li, Miao Yu

Miao Yu

No abstract provided.


Mesophorous Block Copolymer Membrane, Sittinon Nuethong 2015 Iowa State University

Mesophorous Block Copolymer Membrane, Sittinon Nuethong

Symposium on Undergraduate Research and Creative Expression

Block-copolymer research has long been a center of attention among engineers and scientists seeking solutions to combine two thermodynamically incompatible polymers with hybrid properties. This research focuses on creating triblock copolymers from polystyrene, polyisoprene, and polydimethylsiloxane using an anionic polymerization technique to synthesize then etch of one of the polymer’s block to form a mesophorous membrane. A series of experiments was conducted to form block-copolymers of different molecular weights, which were then tested for their flexibility and permeability. The goal is to develop suitable block-copolymer membranes that can be tailored to the specific needs to support “microbial factory” that ...


Increasing Escherichia Coli Membrane Robustness To Long-Chain Fatty Acids, Will Black 2015 Iowa State University

Increasing Escherichia Coli Membrane Robustness To Long-Chain Fatty Acids, Will Black

Symposium on Undergraduate Research and Creative Expression

Product generation through genetically modified microorganisms has enabled scientists to produce hydrocarbons, antibodies, and proteins of their choosing. However, the inhibitory nature of these products reduces production rates and final titer of products. Genetically modifying microorganisms to withstand these products so they can continue to produce product at higher concentrations is just one way to bring these bioproducts to a competitive economic scale. Here, we investigate the deletion of two proteins, protein X and protein Y, associated with fatty acids in Escherichia coli MG1655. These proteins allow for the buildup up fatty acids in the cell, which degrade the cell ...


Enhancing Grain Boundary Ionic Conductivity In Mixed Ionic–Electronic Conductors, Ye Lin, Shumin Fang, Dong Su, Kyle S. Brinkman, Fanglin Chen 2015 University of South Carolina - Columbia

Enhancing Grain Boundary Ionic Conductivity In Mixed Ionic–Electronic Conductors, Ye Lin, Shumin Fang, Dong Su, Kyle S. Brinkman, Fanglin Chen

Faculty Publications

Mixed ionic–electronic conductors are widely used in devices for energy conversion and storage. Grain boundaries in these materials have nanoscale spatial dimensions, which can generate substantial resistance to ionic transport due to dopant segregation. Here, we report the concept of targeted phase formation in a Ce0.8Gd0.2O2−δ–CoFe2O4 composite that serves to enhance the grain boundary ionic conductivity. Using transmission electron microscopy and spectroscopy approaches, we probe the grain boundary charge distribution and chemical environments altered by the phase reaction between the two constituents. The formation of an emergent phase successfully avoids segregation of the Gd dopant ...


Bioinspired Nanomaterials For Bone Regeneration, Esmaiel Jabbari 2015 University of South Carolina - Columbia

Bioinspired Nanomaterials For Bone Regeneration, Esmaiel Jabbari

Esmaiel Jabbari

No abstract provided.


Nanoparticles For Stem-Cell Engineering, Esmaiel Jabbari 2015 University of South Carolina - Columbia

Nanoparticles For Stem-Cell Engineering, Esmaiel Jabbari

Esmaiel Jabbari

No abstract provided.


Parameter Estimates For A Pemfc Cathode, Qingzhi Guo, Vijay A. Sethuraman, Ralph E. White 2015 University of South Carolina - Columbia

Parameter Estimates For A Pemfc Cathode, Qingzhi Guo, Vijay A. Sethuraman, Ralph E. White

Ralph E. White

Five parameters of a model of a polymer electrolyte membrane fuel cell (PEMFC) cathode (the volume fraction of gas pores in the gas diffusion layer, the volume fraction of gas pores in the catalyst layer, the exchange current density of the oxygen reduction reaction, the effective ionic conductivity of the electrolyte, and the ratio of the effective diffusion coefficient of oxygen in a flooded spherical agglomerate particle to the square of that particle radius) were determined by least-squares fitting of experimental polarization curves. The values of parameters obtained in this work indicate that ionic conduction and gas-phase transport are two ...


Separation Of The Petroleum System, Ali Ibrahim Neamah 2015 Western Michigan University

Separation Of The Petroleum System, Ali Ibrahim Neamah

Ali Ibrahim Neamah

This study discusses the overall process of crude oil separation as well as the necessary equipment used in the process. Also discussed and analyzed are potential issues seen in the crude oil extraction process. Reasons why these operation problems may occur are analyzed as well as treatment options for such occurring issues are discussed for employees and students alike. This research is based off of personal involvement at the Nasiriyah Degassing Station located in Dhi Qar, Iraq.


Designed Synthesis Of Nanoporous Organic Polymers For Selective Gas Uptake And Catalytic Applications, Pezhman Arab 2015 Virginia Commonwealth University

Designed Synthesis Of Nanoporous Organic Polymers For Selective Gas Uptake And Catalytic Applications, Pezhman Arab

Theses and Dissertations

Design and synthesis of porous organic polymers have attracted considerable attentions during the past decade due to their wide range of applications in gas storage, gas separation, energy conversion, and catalysis. Porous organic polymers can be pre-synthetically and post-synthetically functionalized with a wide variety of functionalities for desirable applications. Along these pursuits, we introduced new synthetic strategies for preparation of porous organic polymers for selective CO2 capture.

Porous azo-linked polymers (ALPs) were synthesized by an oxidative reaction of amine-based monomers using copper(I) as a catalyst which leads to azo-linkage formation. ALPs exhibit high surface areas of up to ...


Biomolecule Localization And Surface Engineering Within Size Tunable Nanoporous Silica Particles, Daniel M. Schlipf 2015 University of Kentucky

Biomolecule Localization And Surface Engineering Within Size Tunable Nanoporous Silica Particles, Daniel M. Schlipf

Theses and Dissertations--Chemical and Materials Engineering

Mesoporous silica materials are versatile platforms for biological catalysis, isolation of small molecules for detection and separation applications. The design of mesoporous silica supports for tailored protein and biomolecule interactions has been limited by the techniques to demonstrate biomolecule location and functionality as a function of pore size. This work examines the interaction of proteins and lipid bilayers with engineered porous silica surfaces using spherical silica particles with tunable pore diameters (3 – 12 nm) in the range relevant to biomolecule uptake in the pores, and large particle sizes (5 - 15 µm) amenable to microscopy imaging

The differentiation of protein location ...


Pot-In-Pot Reactions: A Simple And Green Approach To Efficient Organic Synthesis, M. B.J. Atkinson, Stephanie Oyola-Reynoso, R. E. Luna, D. K. Bwambok, Martin M. Thuo 2015 University of Massachusetts Boston

Pot-In-Pot Reactions: A Simple And Green Approach To Efficient Organic Synthesis, M. B.J. Atkinson, Stephanie Oyola-Reynoso, R. E. Luna, D. K. Bwambok, Martin M. Thuo

Materials Science and Engineering Publications

Incompatible organic reactions impede efficient green synthesis by making multi-component or cascade reactions a big challenge. This review highlights pot-in-pot reactions (multiple reactions carried out in one pot by separating key reactions with a thin polymeric membrane) as an efficient, green synthetic alternative to conventional synthesis. We discuss the advantages of homogeneous processes to develop new cascade reaction sequences by reviewing the use of polymeric thimbles as selective semi-permeable walls. These thimbles allow small organic molecules to diffuse through while retaining polar reagents, polar solvents, and/or organometallic catalysts. The dynamic and versatile nature of this technique is demonstrated by ...


Limits To The Effect Of Substrate Roughness Or Smoothness On The Odd–Even Effect In Wetting Properties Of N-Alkanethiolate Monolayers, Jiahao Chen, Zhengjia Wang, Stephanie Oyola-Reynoso, Symon M. Gathiaka, Martin M. Thuo 2015 Iowa State University

Limits To The Effect Of Substrate Roughness Or Smoothness On The Odd–Even Effect In Wetting Properties Of N-Alkanethiolate Monolayers, Jiahao Chen, Zhengjia Wang, Stephanie Oyola-Reynoso, Symon M. Gathiaka, Martin M. Thuo

Materials Science and Engineering Publications

This study investigates the effect of roughness on interfacial properties of an n-alkanethiolate self-assembled monolayer (SAM) and uses hydrophobicity to demonstrate the existence of upper and lower limits. This article also sheds light on the origin of the previously unexplained gradual increase in contact angles with increases in the size of the molecule making the SAM. We prepared Au surfaces with a root-mean-square (RMS) roughness of ∼0.2–0.5 nm and compared the wetting properties of n-alkanethiolate (C10–C16) SAMs fabricated on these surfaces. Static contact angles, θs, formed between the SAM and water, diethylene glycol, and ...


Revealing The Nature Of Molecule–Electrode Contact In Tunneling Junctions Using Raw Data Heat Maps, Jacob Sporrer, Jiahao Chen, Zhengjia Wang, Martin M. Thuo 2015 Iowa State University

Revealing The Nature Of Molecule–Electrode Contact In Tunneling Junctions Using Raw Data Heat Maps, Jacob Sporrer, Jiahao Chen, Zhengjia Wang, Martin M. Thuo

Materials Science and Engineering Publications

Mechanistic understanding of charge transport through molecular tunnel junctions requires reproducible and statistically relevant data sets. This challenge has been overcome by development of large area junctions, especially those based on liquid-metal physi-sorbed top-electrodes, such as eutectic gallium–indium. A challenge with these junctions, however, is an inability to diagnose the quality of contact between the top-electrode and the SAMs. Since tunneling currents are dependent on the distance between the two electrodes, we demonstrate that by analyzing all raw unfitted data derived from a measurement using heat-maps, one can deduce the quality of contact and other minor bias-dependent fluctuations in ...


Revisiting The Challenges In Fabricating Uniform Coatings With Polyfunctional Molecules On High Surface Energy Materials, Stephanie Oyola-Reynoso, Zhengjia Wang, Jiahao Chen, Simge Çınar, Boyce Chang, Martin M. Thuo 2015 Iowa State University

Revisiting The Challenges In Fabricating Uniform Coatings With Polyfunctional Molecules On High Surface Energy Materials, Stephanie Oyola-Reynoso, Zhengjia Wang, Jiahao Chen, Simge Çınar, Boyce Chang, Martin M. Thuo

Materials Science and Engineering Publications

Modifying the chemistry of a surface has been widely used to influence interfacial properties of a material or nature of interaction between two materials. This article provides an overview on the role of polyfunctional molecules, specifically silanes, in surface modification of polar surfaces (bearing soft nucleophiles). An emphasis on the mechanism of the reaction in the presence of adsorbed water, where the modifying reagents are hydrolysable, is discussed. To highlight the complexity of the reaction, modification of paper with trichlorosilanes is highlighted. Preparation of hydrophobic cellulosic paper, and structure–property relations under different treatment conditions is used to highlight that ...


Long Term Blood Oxygenation Membranes, Joseph V. Alexander 2015 University of Kentucky

Long Term Blood Oxygenation Membranes, Joseph V. Alexander

Theses and Dissertations--Biomedical Engineering

Hollow fiber membranes are widely used in blood oxygenators to remove carbon dioxide and add oxygen during cardiopulmonary bypass operations. These devices are now widely used off-label by physicians to perform extracorporeal blood oxygenation for patients with lung failure. Unfortunately, the hollow fiber membranes used in these devices fail prematurely due to blood plasma leakage and gas emboli formation.

This project formed ultrathin (~100nm) polymer coatings on polymer hollow fiber membranes. The coatings were intended to “block” existing pores on the exterior surfaces while permitting high gas fluxes. This coating is synthesized using surface imitated control radical polymerization.

The coating ...


Effect Of Plasticizer On Oxygen Permeability Of Cast Polylactic Acid (Pla) Films Determined Using Dynamic Accumulation Method, Kurniawan Yuniarto, Bruce A. Welt, ARIS PURWANTO, Hadi Karia Purwadaria, Ayman Abdellatief, Titi C. Sunarti, Setyo Purwanto 2014 Bogor Agricultural University

Effect Of Plasticizer On Oxygen Permeability Of Cast Polylactic Acid (Pla) Films Determined Using Dynamic Accumulation Method, Kurniawan Yuniarto, Bruce A. Welt, Aris Purwanto, Hadi Karia Purwadaria, Ayman Abdellatief, Titi C. Sunarti, Setyo Purwanto

Journal of Applied Packaging Research

Polylactic acid (PLA) is becoming an increasingly important biopolymer for packaging applications. PLA brittleness limits its applicability. This study evaluated PLA properties with increasing amounts of added polyethylene glycol (PEG) plasticizer. Oxygen transmission rate (OTR) of cast films was determined using the newly available Dynamic Accumulation (DA) method. Arrhenius temperature sensitivity of OTR and polymer Permeability was also determined. Permeability of neat PLA is 4.848 ml mm (STP)/m2 s kPa; hence, 4.84 ml mm (STP)/m2 s kPa, 4.07 ml mm (STP)/m2 s kPa and 5.42 ml mm (STP)/m2 ...


Plasmonic Optical Sensors: Performance Analysis And Engineering Towards Biosensing, Peipei Jia 2014 The University of Western Ontario

Plasmonic Optical Sensors: Performance Analysis And Engineering Towards Biosensing, Peipei Jia

Electronic Thesis and Dissertation Repository

Surface plasmon resonance (SPR) sensing for quantitative analysis of chemical reactions and biological interactions has become one of the most promising applications of plasmonics. This thesis focuses on performance analysis for plasmonic sensors and implementation of plamonic optical sensors with novel nanofabrication techniques.

A universal performance analysis model is established for general two-dimensional plasmonic sensors. This model is based on the fundamental facts of surface plasmon theory. The sensitivity only depends on excitation light wavelength as well as dielectric properties of metal and dielectrics. The expression involves no structure-specified parameters, which validates this formula in broad cases of periodic, quasiperiodic ...


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