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University of Kentucky

Chemical and Materials Engineering Faculty Publications

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Full-Text Articles in Engineering

Strategy For Conjugating Oligopeptides To Mesoporous Silica Nanoparticles Using Diazirine-Based Heterobifunctional Linkers, Md Arif Khan, Ramy W. Ghanim, Maelyn R. Kiser, Mahsa Moradipour, Dennis T. Rogers, John M. Littleton, Luke H. Bradley, Bert C. Lynn, Stephen E. Rankin, Barbara L. Knutson Feb 2022

Strategy For Conjugating Oligopeptides To Mesoporous Silica Nanoparticles Using Diazirine-Based Heterobifunctional Linkers, Md Arif Khan, Ramy W. Ghanim, Maelyn R. Kiser, Mahsa Moradipour, Dennis T. Rogers, John M. Littleton, Luke H. Bradley, Bert C. Lynn, Stephen E. Rankin, Barbara L. Knutson

Chemical and Materials Engineering Faculty Publications

Successful strategies for the attachment of oligopeptides to mesoporous silica with pores large enough to load biomolecules should utilize the high surface area of pores to provide an accessible, protective environment. A two-step oligopeptide functionalization strategy is examined here using diazirine-based heterobifunctional linkers. Mesoporous silica nanoparticles (MSNPs) with average pore diameter of ~8 nm and surface area of ~730 m2/g were synthesized and amine-functionalized. Tetrapeptides Gly-Gly-Gly-Gly (GGGG) and Arg-Ser-Ser-Val (RSSV), and a peptide comprised of four copies of RSSV (4RSSV), were covalently attached via their N-terminus to the amine groups on the particle surface by a heterobifunctional linker, …


High Depth-Of-Discharge Zinc Rechargeability Enabled By A Self-Assembled Polymeric Coating, David J. Arnot, Matthew B. Lim, Nelson S. Bell, Noah B. Schorr, Ryan C. Hill, Andrew Meyer, Yang-Tse Cheng, Timothy N. Lambert Aug 2021

High Depth-Of-Discharge Zinc Rechargeability Enabled By A Self-Assembled Polymeric Coating, David J. Arnot, Matthew B. Lim, Nelson S. Bell, Noah B. Schorr, Ryan C. Hill, Andrew Meyer, Yang-Tse Cheng, Timothy N. Lambert

Chemical and Materials Engineering Faculty Publications

Zinc has the potential for widespread use as an environmentally friendly and cost-effective anode material pending the resolution of rechargeability issues caused by active material loss and shape change. Here, a self-assembled Nafion-coated Celgard 3501 (NC-Celgard) separator is shown to enable unprecedented cycle life of a Zn anode in alkaline electrolyte at high depth-of-discharge (DODZn). Using commercially relevant energy-dense electrodes with high areal capacities of 60 mAh cm–2, Zn–Ni cells tested at 20% DODZn cells achieve over 200 cycles while 50% DODZn cells achieve over 100 cycles before failure. The 20% and 50% DOD …


Advanced Research And Development Of Face Masks And Respirators Pre And Post The Coronavirus Disease 2019 (Covid-19) Pandemic: A Critical Review, Ebuka A. Ogbuoji, Amr M. Zaky, Isabel C. Escobar Jun 2021

Advanced Research And Development Of Face Masks And Respirators Pre And Post The Coronavirus Disease 2019 (Covid-19) Pandemic: A Critical Review, Ebuka A. Ogbuoji, Amr M. Zaky, Isabel C. Escobar

Chemical and Materials Engineering Faculty Publications

The outbreak of the COVID-19 pandemic, in 2020, has accelerated the need for personal protective equipment (PPE) masks as one of the methods to reduce and/or eliminate transmission of the coronavirus across communities. Despite the availability of different coronavirus vaccines, it is still recommended by the Center of Disease Control and Prevention (CDC), World Health Organization (WHO), and local authorities to apply public safety measures including maintaining social distancing and wearing face masks. This includes individuals who have been fully vaccinated. Remarkable increase in scientific studies, along with manufacturing-related research and development investigations, have been performed in an attempt to …


Polymers And Solvents Used In Membrane Fabrication: A Review Focusing On Sustainable Membrane Development, Xiaobo Dong, David Lu, Tequila A. L. Harris, Isabel C. Escobar Apr 2021

Polymers And Solvents Used In Membrane Fabrication: A Review Focusing On Sustainable Membrane Development, Xiaobo Dong, David Lu, Tequila A. L. Harris, Isabel C. Escobar

Chemical and Materials Engineering Faculty Publications

(1) Different methods have been applied to fabricate polymeric membranes with non-solvent induced phase separation (NIPS) being one of the mostly widely used. In NIPS, a solvent or solvent blend is required to dissolve a polymer or polymer blend. N-methyl-2-pyrrolidone (NMP), dimethylacetamide (DMAc), dimethylformamide (DMF) and other petroleum-derived solvents are commonly used to dissolve some petroleum-based polymers. However, these components may have negative impacts on the environment and human health. Therefore, using greener and less toxic components is of great interest for increasing membrane fabrication sustainability. The chemical structure of membranes is not affected by the use of different solvents, …


Fluid Separation And Network Deformation In Wetting Of Soft And Swollen Surfaces, Zhuoyun Cai, Artem Skabeev, Svetlana Morozova, Jonathan T. Pham Feb 2021

Fluid Separation And Network Deformation In Wetting Of Soft And Swollen Surfaces, Zhuoyun Cai, Artem Skabeev, Svetlana Morozova, Jonathan T. Pham

Chemical and Materials Engineering Faculty Publications

When a water drop is placed onto a soft polymer network, a wetting ridge develops at the drop periphery. The height of this wetting ridge is typically governed by the drop surface tension balanced by elastic restoring forces of the polymer network. However, the situation is more complex when the network is swollen with fluid, because the fluid may separate from the network at the contact line. Here we study the fluid separation and network deformation at the contact line of a soft polydimethylsiloxane (PDMS) network, swollen with silicone oil. By controlling both the degrees of crosslinking and swelling, we …


Transforming Corn Stover To Useful Transport Fuel Blends In Resource-Limited Settings, Nicholas Munu, Noble Banadda, Nicholas Kiggundu, Ahamada Zziwa, Isa Kabenge, Jeffrey Seay, Robert Kambugu, Joshua Wanyama, Albrecht Schmidt Feb 2021

Transforming Corn Stover To Useful Transport Fuel Blends In Resource-Limited Settings, Nicholas Munu, Noble Banadda, Nicholas Kiggundu, Ahamada Zziwa, Isa Kabenge, Jeffrey Seay, Robert Kambugu, Joshua Wanyama, Albrecht Schmidt

Chemical and Materials Engineering Faculty Publications

Development of local technologies is crucial to the sustainable energy agenda in resource-limited countries and the world. Strengthening local green technologies and promoting local utilization will reduce carbon emissions that could be generated during transportation and delivery of green products from one country to another. In this paper we developed bio-oil/diesel blends using a low-tech pyrolysis system designed for smallholder farmers in developing countries and tested their appropriateness for diesel engines using standard ASTM methods. Corn stover retrieved from smallholder farmers in Gayaza, Uganda were pyrolyzed in a batch rocket stove reactor at 350 °C and liquid bio-oil harvested. Bio-oil …


Copper Oxide Nanoparticle Diameter Mediates Serum-Sensitive Toxicity In Beas-2b Cells, Angie S. Morris, Brittany E. Givens, Aaron Silva, Aliasger K. Salem Feb 2021

Copper Oxide Nanoparticle Diameter Mediates Serum-Sensitive Toxicity In Beas-2b Cells, Angie S. Morris, Brittany E. Givens, Aaron Silva, Aliasger K. Salem

Chemical and Materials Engineering Faculty Publications

Copper oxide (CuO) nanoparticles (NPs) are abundant in manufacturing processes, but they are an airway irritant. In vitro pulmonary toxicity of CuO NPs has been modeled using cell lines such as human bronchial epithelial cell line BEAS-2B. In 2D in vitro culture, BEAS-2B undergoes squamous differentiation due to the presence of serum. Differentiation is part of the repair process of lung cells in vivo that helps to preserve the epithelial lining of the respiratory tract. Herein, the effects of serum on the hydrodynamic diameter, cellular viability, cellular differentiation, and cellular uptake of 5 and 35 nm CuO NPs are investigated, …


Corrosion Protective Film Formation On Mg Alloys Az 31 By Exposure To Dilute Selenite Solutions, Zhiyuan Feng, Charles C. Xu, Dadi Zhang, Rudolph Buchheit Jan 2021

Corrosion Protective Film Formation On Mg Alloys Az 31 By Exposure To Dilute Selenite Solutions, Zhiyuan Feng, Charles C. Xu, Dadi Zhang, Rudolph Buchheit

Chemical and Materials Engineering Faculty Publications

The study of protective film formation on Mg alloys by exposure to sodium selenite solutions was conducted. Anodic polarization studies, electrochemical impedance spectroscopy studies, morphological analysis, and Energy-dispersive X-ray spectroscopy were performed on AZ31 Mg alloy after coating treatment in different concentrations of sodium selenite. The corrosion resistance was improved by around 5 times compared with control. Improved resistance to localized corrosion was observed in the coatings treated by 5 mM or 10 mM sodium selenite. The protection mechanism was ascribed to the transformation of selenite to insoluble selenium, the formation of insoluble MgSeO3 hydrate, and polymerization of amorphous …


The Characterization Of Purified Citrate-Coated Cerium Oxide Nanoparticles Prepared Via Hydrothermal Synthesis, Matthew L. Hancock, Robert A. Yokel, Matthew J. Beck, Julie L. Calahan, Travis W. Jarrells, Eric J. Munson, George A. Olaniyan, Eric A. Grulke Jan 2021

The Characterization Of Purified Citrate-Coated Cerium Oxide Nanoparticles Prepared Via Hydrothermal Synthesis, Matthew L. Hancock, Robert A. Yokel, Matthew J. Beck, Julie L. Calahan, Travis W. Jarrells, Eric J. Munson, George A. Olaniyan, Eric A. Grulke

Chemical and Materials Engineering Faculty Publications

Hypothesis

Cerium oxide nanoparticles were synthesized using a hydrothermal approach with citric acid as a stabilizing agent. Citric acid adsorption onto the nanoceria particle surface can cease particle formation and create a stable dispersion for an extended shelf life. The product was dialyzed immediately following the synthesis to remove unreacted cerium that could contribute to biological effects. Nanoparticle characterization results are expected to help identify the surface citrate bonding structure.

Experiments

Many characterization techniques were utilized to determine size, morphology, surface properties, and citrate complexation on the nanoceria particle surface. These included transmission electron microscopy, electron energy loss spectroscopy, dynamic …


Review Of Γ’ Rafting Behavior In Nickel-Based Superalloys: Crystal Plasticity And Phase-Field Simulation, Zhiyuan Yu, Xinmei Wang, Fuqian Yang, Zhufeng Yue, James C. M. Li Nov 2020

Review Of Γ’ Rafting Behavior In Nickel-Based Superalloys: Crystal Plasticity And Phase-Field Simulation, Zhiyuan Yu, Xinmei Wang, Fuqian Yang, Zhufeng Yue, James C. M. Li

Chemical and Materials Engineering Faculty Publications

Rafting is an important phenomenon of the microstructure evolution in nickel-based single crystal superalloys at elevated temperature. Understanding the rafting mechanism and its effect on the microstructure evolution is of great importance in determining the structural stability and applications of the single crystal superalloys. Phase-field method, which is an excellent tool to analyze the microstructure evolution at mesoscale, has been gradually used to investigate the rafting behavior. In this work, we review the crystal plasticity theory and phase-field method and discuss the application of the crystal plasticity theory and phase-field method in the analysis of the creep deformation and microstructure …


Desorption From Hot Scandate Cathodes: Effects On Vacuum Device Interior Surfaces After Long-Term Operation, Mujan N. Seif, Thomas John Balk, Matthew J. Beck Nov 2020

Desorption From Hot Scandate Cathodes: Effects On Vacuum Device Interior Surfaces After Long-Term Operation, Mujan N. Seif, Thomas John Balk, Matthew J. Beck

Chemical and Materials Engineering Faculty Publications

Scandate cathodes have exhibited superior emission properties compared to current state-of-the-art “M-type” thermionic cathodes. However, their integration into vacuum devices is limited in part by a lack of knowledge regarding their functional lifespan and behavior during operation. Here, we consider thermal desorption from scandate cathodes by examining the distribution of material deposited on interior surfaces of a sealed vacuum device after ~26,000 h of cathode operation. XPS, EDS, and TEM analyses indicate that on the order of 1 wt.% of the initial impregnate is desorbed during a cathode’s lifetime, Ca does not desorb uniformly with time, and little to no …


Effects Of Laser Power And Substrate On The Raman Shift Of Carbon-Nanotube Papers, Fuqian Yang, Shanshan Wang, Yuling Zhang Nov 2020

Effects Of Laser Power And Substrate On The Raman Shift Of Carbon-Nanotube Papers, Fuqian Yang, Shanshan Wang, Yuling Zhang

Chemical and Materials Engineering Faculty Publications

The progress in the fabrication of carbon-nanotube-based structures has made it possible to use Raman spectroscopy to measure the deformation states of carbon nanotubes and abutting materials. In this work, we investigate the effects of laser power and surrounding materials on the Raman shift of carbon-nanotube (CNT) papers for the laser intensity in a range of 0.071 to 1.415 kW/mm2 without action of mechanical loading. Two different configurations of the CNT papers are used in the Raman measurement; one uses a suspended CNT paper, and the other places a CNT paper on a glass or aluminum substrate. The experimental …


Composite Membranes Derived From Cellulose And Lignin Sulfonate For Selective Separations And Antifouling Aspects, Andrew Steven Colburn, Ronald J. Vogler, Aum Patel, Mariah Bezold, John D. Craven, Chunqing Liu, Dibakar Bhattacharyya Jun 2019

Composite Membranes Derived From Cellulose And Lignin Sulfonate For Selective Separations And Antifouling Aspects, Andrew Steven Colburn, Ronald J. Vogler, Aum Patel, Mariah Bezold, John D. Craven, Chunqing Liu, Dibakar Bhattacharyya

Chemical and Materials Engineering Faculty Publications

Cellulose-based membrane materials allow for separations in both aqueous solutions and organic solvents. The addition of nanocomposites into cellulose structure is facilitated through steric interaction and strong hydrogen bonding with the hydroxy groups present within cellulose. An ionic liquid, 1-ethyl-3-methylimidazolium acetate, was used as a solvent for microcrystalline cellulose to incorporate graphene oxide quantum dots into cellulose membranes. In this work, other composite materials such as, iron oxide nanoparticles, polyacrylic acid, and lignin sulfonate have all been uniformly incorporated into cellulose membranes utilizing ionic liquid cosolvents. Integration of iron into cellulose membranes resulted in high selectivity (> 99%) of neutral …


Optimization Of Induction Quenching Processes For Hss Roll Based On Mmpt Model, Ligang Liu, Hui Yu, Zhiqiang Yang, Chunmei Zhao, Tongguang Zhai Jun 2019

Optimization Of Induction Quenching Processes For Hss Roll Based On Mmpt Model, Ligang Liu, Hui Yu, Zhiqiang Yang, Chunmei Zhao, Tongguang Zhai

Chemical and Materials Engineering Faculty Publications

To improve the comprehensive performance of high speed steel (HSS) cold rolls, the induction hardening processes were analyzed by numerical simulation and experimental research. Firstly, a modified martensitic phase transformation (MMPT) model of the tested steel under stress constraints was established. Then, the MMPT model was fed into DEFORM to simulate the induction quenching processes of working rolls based on an orthogonal test design and the optimal dual frequency of the induction quenching process was obtained. The results indicate that the depth of the roll’s hardened layer increases by 32.5% and the axial residual tensile stress also becomes acceptable under …


Transient Analysis Of Diffusion-Induced Deformation In A Viscoelastic Electrode, Yaohong Suo, Fuqian Yang Jun 2019

Transient Analysis Of Diffusion-Induced Deformation In A Viscoelastic Electrode, Yaohong Suo, Fuqian Yang

Chemical and Materials Engineering Faculty Publications

In this study, we analyze the transient diffuse-induced-deformation of an electrode consisting of the conducting polymer polypyrrole (PPY) by using the theories of linear viscoelasticity and diffusion-induced stress. We consider two constitutive relationships with dependence of viscosity on strain rate: Kelvin-Voigt model and three-parameter solid model. A numerical method is used to solve the problem of one-dimensional, transient diffusion-induced-deformation under potentiostatic operation. The numerical results reveal that the maximum displacement occurs at the free surface and the maximum stress occurs at the fixed end. The inertia term causes the stress to increase at the onset of lithiation. The stress decreases …


Formability Of A Hsas Based On Hot Processing Maps And Texture Analyses, Zhiqiang Yang, Ligang Liu, Tongguang Zhai, Chunmei Zhao, Hui Yu, Qiang Li Apr 2019

Formability Of A Hsas Based On Hot Processing Maps And Texture Analyses, Zhiqiang Yang, Ligang Liu, Tongguang Zhai, Chunmei Zhao, Hui Yu, Qiang Li

Chemical and Materials Engineering Faculty Publications

Aiming to improve the formability of a HSAS Docol 1500 Bor, hot processing maps were obtained based on Prasad, Babu and Murty instability criteria. The hot processing maps based on the above instability criteria are similar and the explanation of its similarity is given. Recrystallization and misorientation in typical quenched specimens were observed by using SEM with a EBSD system. It was found that the fraction values of HAGBs in quenched martensite are all below 0.4 under experimental conditions. Flow location bands occurs at lower deformation temperatures and higher strain rates. The textures in martensite mainly include ⟨110⟩ / / …


Surface-Controlled Dissolution Rates: A Case Study Of Nanoceria In Carboxylic Acid Solutions, Eric A. Grulke, Matthew J. Beck, Robert A. Yokel, Jason M. Unrine, Uschi M. Graham, Matthew L. Hancock Apr 2019

Surface-Controlled Dissolution Rates: A Case Study Of Nanoceria In Carboxylic Acid Solutions, Eric A. Grulke, Matthew J. Beck, Robert A. Yokel, Jason M. Unrine, Uschi M. Graham, Matthew L. Hancock

Chemical and Materials Engineering Faculty Publications

Nanoparticle dissolution in local milieu can affect their ecotoxicity and therapeutic applications. For example, carboxylic acid release from plant roots can solubilize nanoceria in the rhizosphere, affecting cerium uptake in plants. Nanoparticle dispersions were dialyzed against ten carboxylic acid solutions for up to 30 weeks; the membrane passed cerium-ligand complexes but not nanoceria. Dispersion and solution samples were analyzed for cerium by inductively coupled plasma mass spectrometry (ICP-MS). Particle size and shape distributions were measured by transmission electron microscopy (TEM). Nanoceria dissolved in all carboxylic acid solutions, leading to cascades of progressively smaller nanoparticles and producing soluble products. The dissolution …


Near-Surface Material Phases And Microstructure Of Scandate Cathodes, Xiaotao Liu, Bernard K. Vancil, Matthew J. Beck, Thomas John Balk Feb 2019

Near-Surface Material Phases And Microstructure Of Scandate Cathodes, Xiaotao Liu, Bernard K. Vancil, Matthew J. Beck, Thomas John Balk

Chemical and Materials Engineering Faculty Publications

Scandate cathodes that were fabricated using the liquid-solid process and that exhibited excellent emission performance were characterized using complementary state-of-the-art electron microscopy techniques. Sub-micron BaAl2O4 particles were observed on the surfaces and edges of tungsten particles, as seen in cross-section samples extracted from the scandate cathode surface regions. Although several BaAl2O4 particles were observed to surround smaller Sc2O3 nanoparticles, no chemical mixing of the two oxides was detected, and in fact the distinct oxide phases were separately verified by chemical analysis and also by 3D elemental tomography. Nanobeam electron diffraction confirmed …


Increasing Salt Rejection Of Polybenzimidazole Nanofiltration Membranes Via The Addition Of Immobilized And Aligned Aquaporins, Priyesh Ashokrao Wagh, Xinyi Zhang, Ryan Blood, Peter M. Kekenes-Huskey, Prasangi Rajapaksha, Yinan Wei, Isabel C. Escobar Feb 2019

Increasing Salt Rejection Of Polybenzimidazole Nanofiltration Membranes Via The Addition Of Immobilized And Aligned Aquaporins, Priyesh Ashokrao Wagh, Xinyi Zhang, Ryan Blood, Peter M. Kekenes-Huskey, Prasangi Rajapaksha, Yinan Wei, Isabel C. Escobar

Chemical and Materials Engineering Faculty Publications

Aquaporins are water channel proteins in cell membrane, highly specific for water molecules while restricting the passage of contaminants and small molecules, such as urea and boric acid. Cysteine functional groups were installed on aquaporin Z for covalent attachment to the polymer membrane matrix so that the proteins could be immobilized to the membranes and aligned in the direction of the flow. Depth profiling using x-ray photoelectron spectrometer (XPS) analysis showed the presence of functional groups corresponding to aquaporin Z modified with cysteine (Aqp-SH). Aqp-SH modified membranes showed a higher salt rejection as compared to unmodified membranes. For 2 M …


Fluorescence Of Cdse/Zns Quantum Dots In Toluene: Effect Of Cyclic Temperature, Ting Chen, Weiling Luan, Shaofu Zhang, Fuqian Yang Feb 2019

Fluorescence Of Cdse/Zns Quantum Dots In Toluene: Effect Of Cyclic Temperature, Ting Chen, Weiling Luan, Shaofu Zhang, Fuqian Yang

Chemical and Materials Engineering Faculty Publications

Quantum dots (QDs) are the potential material for the application in optical thermometry, and have been successfully applied to solar cells, LEDs, bio-labeling, structural health monitoring, etc. In this paper, we study the fluorescence properties of CdSe/ZnS QDs in toluene under the action of heating-cooling cycles. The experimental results show that, in a heating-cooling cycle, increasing temperature causes red-shift of the emission peak and the decrease of the PL intensity, and decreasing temperature causes blue-shift of the emission peak and the increase of the PL intensity. The surface structures of the QDs likely are dependent on the cycle numbers, which …


Coatings On Mammalian Cells: Interfacing Cells With Their Environment, Kara A. Davis, Pei-Jung Wu, Calvin F. Cahall, Cong Li, Anuhya Gottipati, Brad J. Berron Jan 2019

Coatings On Mammalian Cells: Interfacing Cells With Their Environment, Kara A. Davis, Pei-Jung Wu, Calvin F. Cahall, Cong Li, Anuhya Gottipati, Brad J. Berron

Chemical and Materials Engineering Faculty Publications

The research community is intent on harnessing increasingly complex biological building blocks. At present, cells represent a highly functional component for integration into higher order systems. In this review, we discuss the current application space for cellular coating technologies and emphasize the relationship between the target application and coating design. We also discuss how the cell and the coating interact in common analytical techniques, and where caution must be exercised in the interpretation of results. Finally, we look ahead at emerging application areas that are ideal for innovation in cellular coatings. In all, cellular coatings leverage the machinery unique to …


Determining The Degree Of [001] Preferred Growth Of Ni(Oh)2 Nanoplates, Taotao Li, Ning Dang, Wanggang Zhang, Wei Liang, Fuqian Yang Nov 2018

Determining The Degree Of [001] Preferred Growth Of Ni(Oh)2 Nanoplates, Taotao Li, Ning Dang, Wanggang Zhang, Wei Liang, Fuqian Yang

Chemical and Materials Engineering Faculty Publications

Determining the degree of preferred growth of low-dimensional materials is of practical importance for the improvement of the synthesis methods and applications of low-dimensional materials. In this work, three different methods are used to analyze the degree of preferred growth of the Ni(OH)2 nanoplates synthesized without the use of a complex anion. The results suggest that the preferred growth degree of the Ni(OH)2 nanoplates calculated by the March parameter and the expression given by Zolotoyabko, which are based on the analysis and texture refinement of the X-ray diffraction pattern, are in good accordance with the results measured by …


Cellulose-Specific Type B Carbohydrate Binding Modules: Understanding Oligomeric And Non-Crystalline Substrate Recognition Mechanisms, Abhishek A. Kognole, Christina M. Payne Nov 2018

Cellulose-Specific Type B Carbohydrate Binding Modules: Understanding Oligomeric And Non-Crystalline Substrate Recognition Mechanisms, Abhishek A. Kognole, Christina M. Payne

Chemical and Materials Engineering Faculty Publications

Background: Effective enzymatic degradation of crystalline polysaccharides requires a synergistic cocktail of hydrolytic enzymes tailored to the wide-ranging degree of substrate crystallinity. To accomplish this type of targeted carbohydrate recognition, nature produces multi-modular enzymes, having at least one catalytic domain appended to one or more carbohydrate binding modules (CBMs). The Type B CBM categorization encompasses several families (i.e., protein folds) of CBMs that are generally thought to selectively bind oligomeric polysaccharides; however, a subset of cellulose-specific CBM families (17 and 28) appear to bind non-crystalline cellulose more tightly than oligomers and in a manner that discriminates between surface topology.

Results: …


Highly Thiolated Poly (Beta-Amino Ester) Nanoparticles For Acute Redox Applications, Andrew L. Lakes, David A. Puleo, J. Zach Hilt, Thomas D. Dziubla Oct 2018

Highly Thiolated Poly (Beta-Amino Ester) Nanoparticles For Acute Redox Applications, Andrew L. Lakes, David A. Puleo, J. Zach Hilt, Thomas D. Dziubla

Chemical and Materials Engineering Faculty Publications

Disulfides are used extensively in reversible cross-linking because of the ease of reduction into click-reactive thiols. However, the free-radical scavenging properties upon reduction are often under-considered. The free thiols produced upon reduction of this disulfide material mimic the cellular reducing chemistry (glutathione) that serves as a buffer against acute oxidative stress. A nanoparticle formulation producing biologically relevant concentrations of thiols may not only provide ample chemical conjugation sites, but potentially be useful against severe acute oxidative stress exposure, such as in targeted radioprotection. In this work, we describe the synthesis and characterization of highly thiolated poly (β-amino ester) (PBAE) nanoparticles …


Local Deformation And Texture Of Cold-Rolled Aa6061 Aluminum Alloy, Diaoyu Zhou, Wenwen Du, Xiyu Wen, Junwei Qiao, Wei Liang, Fuqian Yang Oct 2018

Local Deformation And Texture Of Cold-Rolled Aa6061 Aluminum Alloy, Diaoyu Zhou, Wenwen Du, Xiyu Wen, Junwei Qiao, Wei Liang, Fuqian Yang

Chemical and Materials Engineering Faculty Publications

Using cold rolling, we plastically deform AA6061 sheets at room temperature and investigate the variations of the microstructures, textures and local deformation of the cold-rolled AA6061 sheets as functions of thickness reduction (Δt/t0, t0 and t are the thicknesses of the AA6061 sheet before and after the cold rolling, respectively). The volume fraction of total deformation texture is relatively independent of the thickness reduction for Δt/t0 ≤ 30%, and becomes an approximately linearly increasing function of the thickness reduction for Δt/t0 > 30%. Increasing the thickness reduction causes the increase of the Vickers hardness of the …


Self-Cleaning Nanocomposite Membranes With Phosphorene-Based Pore Fillers For Water Treatment, Joyner Eke, Katherine Elder, Isabel Escobar Sep 2018

Self-Cleaning Nanocomposite Membranes With Phosphorene-Based Pore Fillers For Water Treatment, Joyner Eke, Katherine Elder, Isabel Escobar

Chemical and Materials Engineering Faculty Publications

Phosphorene is a two-dimensional material exfoliated from bulk phosphorus and it possesses a band gap. Specifically, relevant to the field of membrane science, the band gap of phosphorene provides it with potential photocatalytic properties, which could be explored in making reactive membranes that can self-clean. The goal of this study was to develop an innovative and robust membrane that is able to control and reverse fouling with minimal changes in membrane performance. To this end, for the first time, membranes have been embedded with phosphorene. Membrane modification was verified by the presence of phosphorus on membranes, along with changes in …


Aging Response And Precipitation Behavior After 5% Pre-Deformation Of An Al-Mg-Si-Cu Alloy, Shuoxun Jin, Tungwai Ngai, Liejun Li, Shian Jia, Tongguang Zhai, Dongjie Ke Aug 2018

Aging Response And Precipitation Behavior After 5% Pre-Deformation Of An Al-Mg-Si-Cu Alloy, Shuoxun Jin, Tungwai Ngai, Liejun Li, Shian Jia, Tongguang Zhai, Dongjie Ke

Chemical and Materials Engineering Faculty Publications

In this study, Al-1.00 Mg-0.65 Si-0.24 Cu alloy was solution heat-treated, water-quenched, and then pre-deformed for 5% before aging. The peak hardness and yield strength of the pre-deformed sample with subsequent artificial aging were similar to that of a T6 condition sample. It was also found that the pre-deformation treatment could inhibit the negative influence of natural aging to some degree. After seven days of natural aging, the pre-deformed sample obtained better peak hardness and yield strength upon artificial aging than the sample without pre-deformation. In addition, the pre-deformation treatment could reduce 50% of the artificial aging time to reach …


Investigation Of The Use Of A Bio-Derived Solvent For Non-Solvent-Induced Phase Separation (Nips) Fabrication Of Polysulfone Membranes, Xiaobo Dong, Amna Al-Jumaily, Isabel Escobar May 2018

Investigation Of The Use Of A Bio-Derived Solvent For Non-Solvent-Induced Phase Separation (Nips) Fabrication Of Polysulfone Membranes, Xiaobo Dong, Amna Al-Jumaily, Isabel Escobar

Chemical and Materials Engineering Faculty Publications

Organic solvents, such as N-methyl-2-pyrrolidone (NMP) and dimethylacetamide (DMAc), have been traditionally used to fabricate polymeric membranes. These solvents may have a negative impact on the environment and human health; therefore, using renewable solvents derived from biomass is of great interest to make membrane fabrication sustainable. Methyl-5-(dimethylamino)-2-methyl-5-oxopentanoate (Rhodiasolv PolarClean) is a bio-derived, biodegradable, nonflammable and nonvolatile solvent. Polysulfone is a commonly used polymer to fabricate membranes due to its thermal stability, strong mechanical strength and good chemical resistance. From cloud point curves, PolarClean showed potential to be a solvent for polysulfone. Membranes prepared with PolarClean were investigated in terms of …


Multienzyme Immobilized Polymeric Membrane Reactor For The Transformation Of A Lignin Model Compound, Rupam Sarma, Md. Saiful Islam, Mark P. Running, Dibakar Bhattacharyya Apr 2018

Multienzyme Immobilized Polymeric Membrane Reactor For The Transformation Of A Lignin Model Compound, Rupam Sarma, Md. Saiful Islam, Mark P. Running, Dibakar Bhattacharyya

Chemical and Materials Engineering Faculty Publications

We have developed an integrated, multienzyme functionalized membrane reactor for bioconversion of a lignin model compound involving enzymatic catalysis. The membrane bioreactors were fabricated through the layer-by-layer assembly approach to immobilize three different enzymes (glucose oxidase, peroxidase and laccase) into pH-responsive membranes. This novel membrane reactor couples the in situ generation of hydrogen peroxide (by glucose oxidase) to oxidative conversion of a lignin model compound, guaiacylglycerol-β-guaiacyl ether (GGE). Preliminary investigation of the efficacy of these functional membranes towards GGE degradation is demonstrated under convective flow mode. Over 90% of the initial feed could be degraded with the multienzyme immobilized membranes …


Orthogonal Photo-Switching Of Supramolecular Patterned Surfaces, Dongsheng Wang, Frank Schellenberger, Jonathan T. Pham, Hans-Jürgen Butt, Si Wu Mar 2018

Orthogonal Photo-Switching Of Supramolecular Patterned Surfaces, Dongsheng Wang, Frank Schellenberger, Jonathan T. Pham, Hans-Jürgen Butt, Si Wu

Chemical and Materials Engineering Faculty Publications

We used Azo/α-CD and ipAzo/γ-CD host–guest complexes to demonstrate that four independent stable states can be orthogonally photo-switched by UV (365 nm), blue (470 nm), green (530 nm) and red light (625 nm). A supramolecular patterned surface was fabricated and orthogonally photo-switched by light with different wavelengths.