Chemical Engineering Commons^™

Electrochemical Detection Of Hydrogen Peroxide At Aunps Modified Electrode Using P-Hydroxyphenylboronic Acid As A Precursor, Chun-Yan Wang, Xiao-Qiu Liu, Ying-Xin Qi

Journal of Electrochemistry

We developed a new method for electrochemical detection of hydrogen peroxide (H₂O₂) based on boronate oxidation of p-hydroxyphenylboronic acid. This method using p-aminophenol which is produced from the reaction of H₂O₂ and p-aminophenylboronic acid as a well electrochemical probe, combined with a gold nanoparticles (AuNPs) modified electrode for an indirect detection of H₂O₂. Because of the large surface area and enhanced electrocatalytic behavior by the AuNPs modified electrode, the detection sensitivity was improved. The method could detect H₂O₂ in the concentration range of 1 ~ 100 …

Synthesis Of Fe, N-Doped Graphene/Carbon Black Composite With High Catalytic Activity For Oxygen Reduction Reaction, Chi Chen, Zhi-You Zhou, Xin-Sheng Zhang, Shi-Gang Sun

Journal of Electrochemistry

Oxygen reduction reaction (ORR) is a bottleneck for improving the efficiency of proton-exchange membrane fuel cells as a cathode reaction due to its sluggish kinetics. The exploitation of low cost and high performance non-precious metal catalysts such as Fe/N/C based materials toward ORR has attracted extensive attentions. In this work, the Fe, N-doped graphene nanosheets/carbon black composite was prepared by hydrothermal polymerization and followed by a twice-heat-treatment procedure using 2-aminoimidazole as an N precursor, FeCl₃ as an Fe precursor and KJ600 carbon black as a support. The TEM images revealed that the graphene nanosheets were separated by carbon black …

Electrochemical Syntheses Of Graphene And Its Composites, Bo Zhao, Li Jiang, Ming-Hui Yuen, Xian-Zhu Fu, Rong Sun, Ching-Ping Wong

Journal of Electrochemistry

Graphene is a kind of ideal two-dimensional flat carbon nanomaterials which have unique chemical and physical properties. The attractive potential applications must be based on the high quality mass production of graphene. However, it remains a huge challenge. An electrochemical approach is a fast, environmental friendly and easy-operating method. single- or multi-layered graphene flakes can easily be produced in short periods of time. In this review, the structure, properties and preparation methods of graphene are first introduced. Accordingly, the electrochemical approaches used for the productions of graphene flakes, graphene/inorganic nanocomposites, graphene/polymer composites and graphene analogues are highlighted. Finally, challenges and …

Electricity Generation Of Microbial Fuel Cell Using Stainless Steel Mesh As Cathode, Hong-Yan Dai, Hui-Min Yang, Xian Liu, Xuan Jian, Xiu-Li Song, Zhen-Hai Liang

Journal of Electrochemistry

In the present work, a dual-chamber microbial fuel cell (MFC) was constructed with aeration tank sludge as an inoculum, carbon felt as an anode and stainless steel mesh without any modification as a cathode. The influence of the cathode size was investigated in terms of voltage output, power generation and electrochemical impedance. The long-term durability of the stainless steel mesh cathode was also evaluated. Results showed that the stainless steel mesh exhibited satisfactory long-term durability as MFC cathode. When the stainless steel mesh size was 2 × 2 cm², the maximum output voltage, power density, the internal resistance …

The Study On Comparison Of Electrochemical Performance In Microbial Fuel Cell With Glucose And Sodium Acetate Acting As Substrates, Lei Fan, Yu Zhao, Ting Li, Qin-Bo Yuan, En-Zhi Wang, Xiao-Bin Wang, Jun-Wen Wang

Journal of Electrochemistry

By inoculating aerobic sludge and anaerobic sludge from the sewage treatment plant, two sets of dual-chamber microbial fuel cells (MFCs) were built with either glucose or sodium acetate acting as a substrate. Accordingly, the electrochemical performances of MFCs were explored with the concentration of the substrates being 0.0335 mol⋅L^-1. The results of the comparative study in glucose system and sodium acetate system showed that the impedance values of anodic half cell were 222 Ω for glucose and 213.67 Ω for sodium acetate, implying no significant effect on the internal resistance in battery with the different substrates. The exchange …

Thermal Transport Properties Of Dry Spun Carbon Nanotube Sheets, Heath E. Misak, James L. Rutledge, Eric D. Swenson, Shankar Mall

Faculty Publications

The thermal properties of carbon nanotube- (CNT-) sheet were explored and compared to copper in this study. The CNT-sheet was made from dry spinning CNTs into a nonwoven sheet. This nonwoven CNT-sheet has anisotropic properties in in-plane and out-of-plane directions. The in-plane direction has much higher thermal conductivity than the out-of-plane direction. The in-plane thermal conductivity was found by thermal flash analysis, and the out-of-plane thermal conductivity was found by a hot disk method. The thermal irradiative properties were examined and compared to thermal transport theory. The CNT-sheet was heated in the vacuum and the temperature was measured with an …

Direct Band Gap Gallium Antimony Phosphide (GasbXP1-X) Alloys, H. B. Russell, A. N. Andriotis, Madhu Menon, J. B. Jasinski, A. Martinez-Garcia, M. K. Sunkara

Center for Computational Sciences Faculty Publications

Here, we report direct band gap transition for Gallium Phosphide (GaP) when alloyed with just 1–2 at% antimony (Sb) utilizing both density functional theory based computations and experiments. First principles density functional theory calculations of GaSb_xP_1−x alloys in a 216 atom supercell configuration indicate that an indirect to direct band gap transition occurs at x = 0.0092 or higher Sb incorporation into GaSb_xP_1−x. Furthermore, these calculations indicate band edge straddling of the hydrogen evolution and oxygen evolution reactions for compositions ranging from x = 0.0092 Sb up to at least x = 0.065 …

Sensitivity Of Neural Stem Cell Survival, Differentiation And Neurite Outgrowth Within 3d Hydrogels To Environmental Heavy Metals, Sameera Tasneem, Kurt Farrell, Moo Yeal Lee, Chandrasekhar R. Kothapalli

Chemical & Biomedical Engineering Faculty Publications

© 2015 Elsevier Ireland Ltd. We investigated the sensitivity of embryonic murine neural stem cells exposed to 10 pM-10. μM concentrations of three heavy metals (Cd, Hg, Pb), continuously for 14 days within 3D collagen hydrogels. Critical endpoints for neurogenesis such as survival, differentiation and neurite outgrowth were assessed. Results suggest significant compromise in cell viability within the first four days at concentrations ≥10. nM, while lower concentrations induced a more delayed effect. Mercury and lead suppressed neural differentiation at as low as 10 pM concentration within 7 days, while all three metals inhibited neural and glial differentiation by day …

Controlling The Structure And Dynamics Of Magnetoresponsive Particle Suspensions For Enhanced Transport Phenomena, Kyle J. Solis

Chemical and Biological Engineering ETDs

The work contained herein describes the use of various magnetic fields to control the structure and dynamics of magnetic particle suspensions, with the practical aim of enhancing momentum, heat, and mass transport. The magnetic fields are often multiaxial and can consist of up to three orthogonal components that may be either static (dc), time-dependent (ac), or some combination thereof. The magnetic particles are composed of a ferromagnetic material—such as iron, nickel, cobalt, or Permalloy—and can exist in a variety of shapes, including spheres, platelets, and rods. The shape of the particles is particularly important, as this can determine the type …

Graphene Oxide Quantum Dots Covalently Functionalized Pvdf Membrane With Significantly-Enhanced Bactericidal And Antibiofouling Performances, Zhiping Zeng, Dingshan Yu, Ziming He, Jing Liu, Fang-Xing Xiao, Yan Zhang, Rong Wang, Dibakar Bhattacharyya, Timothy Thatt Yang Tan

Chemical and Materials Engineering Faculty Publications

Covalent bonding of graphene oxide quantum dots (GOQDs) onto amino modified polyvinylidene fluoride (PVDF) membrane has generated a new type of nano-carbon functionalized membrane with significantly enhanced antibacterial and antibiofouling properties. A continuous filtration test using E. coli containing feedwater shows that the relative flux drop over GOQDs modified PVDF is 23%, which is significantly lower than those over pristine PVDF (86%) and GO-sheet modified PVDF (62%) after 10 h of filtration. The presence of GOQD coating layer effectively inactivates E. coli and S. aureus cells, and prevents the biofilm formation on the membrane surface, producing excellent antimicrobial activity and …

The Effect Of Assembly Technique On Weak Polyelectrolyte Multilayer Film Morphology And Humidity Swelling/Deswelling Behavior, Ziyang Yin

Graduate Theses - Chemical Engineering

The goal of this research is to investigate the film morphology and humidity swelling/deswelling behavior of polyelectrolyte multilayers (PEMs) that are constructed from poly(allylamine hydrochloride) (PAH) and poly(acrylic acid) (PAA) by two assembly techniques: automated dipping layer-by-layer (LbL) and spin-assisted (SA) LbL. Two sets of pH polyelectrolyte solution conditions were tested: (PAH7.5/PAA3.5) and (PAH7.0/PAA7.0). It was found that when the films were constructed with the same number of bilayers (=20 bilayers), SA-LbL (PAH7.5/PAA3.5) has a greater thickness than (PAH7.0/PAA7.0). (PAH7.5/PAA3.5) thin films constructed by automated dipping LbL did not result in a uniform film morphology, making thickness comparisons between techniques …

Microbial Biofilm Development And Electron Transfer In Electrochemical Systems, Jose Cornejo

Chemical and Biological Engineering ETDs

Energy harvesting from microorganisms has created vibrant research efforts for the past 20 years that has lead to the development of emerging topics such as microbial electrochemistry, biofilm formation in electrochemical systems and alternative energy technologies applied in environmental processes. In this study we present procedures that aim for further understanding of bacterial physiological conditions in electrochemical systems and interactions between biofilms and solid surfaces, particularly, for the facultative anaerobe Shewanella oneidensis MR-1. These systems consist of microbial fuel cells (MFCs) whose anode component will be evaluated with regards to performance, electrical current generation, and microbial coverage and biofilm development. …

The Influence Of Season, Heating Mode And Slope Angle On Wildland Fire Behavior, Jonathan R. Gallacher

Theses and Dissertations

Wildland fire behavior research in the last 100 years has largely focused on understanding the physical phenomena behind fire spread and on developing models that can predict fire behavior. Research advances in the areas of live-fuel combustion and combustion modeling have highlighted several weaknesses in the current approach to fire research. Some of those areas include poor characterization of solid fuels in combustion modeling, a lack of understanding of the dominant heat transfer mechanisms in fire spread, a lack of understanding regarding the theory of live-fuel combustion, and a lack of understanding regarding the behavior of flames near slopes. In …

Enhanced Cycle Life And Capacity Retention Of Iron Oxide Ultrathin Film Coated Sno₂ Nanoparticles At High Current Densities, Sai Abhishek Palaparty, Rajankumar L. Patel, Xinhua Liang

Chemical and Biochemical Engineering Faculty Research & Creative Works

Tin oxide (SnO₂) has a high theoretical capacity (∼782 mA h g^-1), but it experiences large volume changes during charge and discharge cycles that cause rapid capacity fade, which limits its practical use as an anode material. In an attempt to solve this, we coated these particles with ultrathin electrochemically active iron oxide (FeO_x) films that act as an artificial solid electrolyte interphase layer, thus stabilizing the SnO₂ particles for better longevity of significantly improved performance at high current densities in a practical voltage window. Since there exists a tradeoff between species transport …

Composition And Manufacturing Effects On Electrical Properties Of Li/Fes2 Thermal Battery Cathodes, Emilee Lolita Reinholz

Chemical and Biological Engineering ETDs

Li/FeS2 thermal batteries provide a stable, robust, and reliable power source capable of long-term electrical energy storage without performance degradation. These systems rely on a eutectic salt that melts at elevated temperature, activating the cell. When the electrolyte melts, the cathode becomes a suspension, with cathode particles suspended in a molten salt. The suspension experiences mechanical deformation, or slumping.' This slump changes the mechanical compression of the cell, as well as the tortuosity and electronic and ionic conductivity of the cell as the cathode mesostructure is reordered in response to the external compressive stress. The combined effect of deformation, component …

Characterization Of Silica-Based And Borate-Based, Titanium-Containing Bioactive Glasses For Coating Metallic Implants, Omar Rodriguez, Declan J. Curran, Marcello Papini, Lana M. Placek, Anthony W. Wren, Emil H. Schemitsch, Paul Zalzal, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Bioactive glasses have found applications in diverse fields, including orthopedics and dentistry, where they have been utilized for the fixation of bone and teeth and as scaffolds for drug delivery. The present work outlines the characterization of two novel titanium-containing glass series, one silica-based and one borate-based. For the silica-based series, titanium is added at the expense of silicon dioxide whereas for the borate-based series, it is added at the expense of boron oxide as confirmed by Energy Dispersive Spectroscopy. Amorphous structures are obtained for silica-based glass at 15 mol% TiO₂ and for borate-based glasses at 0 mol% and …

Laboratory Studies Of The Biodegradation Of Chemically Dispersed Oil: Effect Of Droplet Size And Nutrient Amendment, Christopher D'Ambrose

Dissertations

Oil spills could have devastating effects on the shorelines, and for this reason, chemical dispersants are commonly used to disperse the oil slick in the water column, preventing it from reaching the shorelines. However, the long term fate of dispersed oil depends on its biodegradation by indigenous microorganisms, which in turn depends on the concentration of nutrients in water and on the droplet size distribution.

Using water from the shorelines of Atlantic City, we placed the water with oil and dispersant inside EPA Baffled Flasks and placed them on rotatory shakers. We selected two speeds: high (250 rpm) and low …

Synthesis Of A Renewable Sourced Thermotropic Polyester With 2,5-Furandicarboxylic Acid, Alicia Marie Marguerite Hurst

Theses

With the rapid depletion of non-renewable sourced materials, unpredictable fluctuations in the prices of fossil fuels, and increased environmental awareness the need to develop biobased materials grows ever more desperate. Furan derivatives sourced from hexoses provide a promising solution for replacing petrochemical based materials. One furan derivative in particular, 2,5-furandicarboxylic acid (FDCA), is especially promising due to its structural similarity to terephthalic acid and potential for use in the production of polyesters similar to PET, PPT, and PBT. This study investigated the synthesis, thermal and liquid crystalline properties of a totally renewable sourced thermotropic polyester based on FDCA. Fructose was …

Computational And Experimental Determination Of The Hydrodynamics In A Stirred Unbaffled Vessel Provided With Angle-Mounted Axial Impellers, Ji Ma

Theses

In most industrial applications, stirred tanks and reactors are typically provided with baffles to improve their mixing characteristics. However, in a number of pharmaceutical production facilities unbaffled vessels are commonly used. The absence of baffles is preferred in such cases because it reduces the potential for contamination and makes cleaning the vessel between batches easier. However, the lack of baffles also has a negative impact on the system’s hydrodynamics since it often results in poor mixing of the batch, especially if the impeller is centrally placed, since the liquid in such a system is subject to a strong tangential flow, …

A Preliminary Investigation Of The Sterile-Filterability Of Bcs Class Ii Drug Nanosuspensions Prepared Via Wet Stirred Media Milling, Parul Ohri

Theses

Drug nanoparticles can achieve targeting capabilities, enhanced dissolution rates and improved bioavailability when injected intravenously. Sterile filtration of drug nanoparticle suspensions (nanosuspensions) is critically needed for administration by intravenous delivery route. Avoiding gamma irradiation and high temperatures, sterile filtration could be an effective process to sterilize drug nanosuspensions. On the other hand, two major challenges must be tackled: drug particles must at least be smaller than the filter pore size and minimum amount of non-toxic stabilizers must be used to prevent side effects like pain on the injection site. The aim of this study is to prepare naproxen (NPX) nanosuspensions …