Chemistry Commons^™

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 …

Temperature Effects On Properties Of Aerospace Nickel Hydrogen Cells, Hai-Chang Zhang, Yu-Qi Diao, Wen-Cheng Ming, Xue-Ying Ren, Fei Ding

Journal of Electrochemistry

This has been done using the 60 Ah nickel-hydrogen cell to investigate the temperature effects on properties of aerospace nickel hydrogen cells. The charge-discharge, trickle charge, overcharge, self-discharge and cycle life tests were carried out at different temperatures. The results show that the discharge capacity and overcharge rate were increased first, and then decreased with the raising temperature. On the other hand, the trickle charge value and the 3 days self-discharge rate were raised with increasing temperature. When the temperature was -5 ^oC, the discharge capacity of cell reached the maximum discharge capacity of 63.68 Ah. Based on the …

Effect Of Flame Retardant On Electrochemical Performances Of Lithium Ion Battery With Lini0.4Co0.2Mn0.4O2 As A Positive Electrode Material, Yan-Zhuo Lv, Yong-Xian Ge, Zhen-Bo Wang, Ke Ke

Journal of Electrochemistry

The effect of flame retardant on the electrochemical performances of lithium ion battery by using LiNi_0.4Co_0.2Mn_0.4O₂ as a positive material was studied by measuring the first charge-discharge, cycling, circulation, and AC impedance curves. The experimental data indicated that the discharge capacity of the battery decreased, while the charge transfer resistance and the lithium ion diffusion resistance increased with the increases in the concentrations of the flame retardant in the electrolyte solutions. Furthermore, the stability of the battery at small discharge ratios and the cyclic performance were also improved by the addition of flame …

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 …

One-Dimensional Nanostructure And Sensing Applications: Tin Dioxide Nanowires And Carbon Nanotubes, Hoang Anh Tran

Dissertations and Theses

The key challenge for a nanomaterial based sensor is how to synthesize in bulk quantity and fabricate an actual device with insightful understanding of operational mechanisms during performance. I report here effective, controllable methods that exploit the concepts of the "green approach" to synthesize two different one-dimensional nanostructures, including tin oxide nanowires and carbon nanotubes. The syntheses are followed by product characterization and sensing device fabrications as well as sensor performance understanding at the molecular level. Sensor-analyte response and recovery kinetics are also presented.

The first part of the thesis describes bulk-scale synthesis and characterization of tin oxide nanowires by …

Water Condensation And Protein Adsorption On Hybrid Superhydrophobic-Hydrophilic Surfaces, Bikash Mondal

Dissertations, Theses, and Capstone Projects

This thesis describes the study of protein adsorption and water condensation on hybrid superhydrophobic-hydrophilic surfaces for various technological applications such as diagnostics, artificial organs and medical devices, water collection, and heat transfer.

In the chapter 1, a general introduction to wetting theories, superhydrophobic surface, and hybrid surfaces is given. In chapter 2, design and fabrication of a hybrid superhydrophobic surface for studying dropwise condensation and heat transfer is discussed. Effect of surface chemistry and wettability on protein adsorption is discussed in the chapter 3. Finally, in chapter 4, the protein adsorption study on hybrid superhydrophobic surfaces made by 3D-printing and …

Strain Effects On The Work Function Of An Organic Semiconductor, Yanfei Wu, Annabel R. Chew, Geoffrey A. Rojas, Gjergji Sini, Greg Haugstad, Alex Belianinov, Sergei V. Kalinin, Hong Li, Chad Risko, Jean-Luc Brédas, Alberto Salleo, C. Daniel Frisbie

Chemistry Faculty Publications

Establishing fundamental relationships between strain and work function (WF) in organic semiconductors is important not only for understanding electrical properties of organic thin films, which are subject to both intrinsic and extrinsic strains, but also for developing flexible electronic devices. Here we investigate tensile and compressive strain effects on the WF of rubrene single crystals. Mechanical strain induced by thermal expansion mismatch between the substrate and rubrene is quantified by X-ray diffraction. The corresponding WF change is measured by scanning Kelvin probe microscopy. The WF of rubrene increases (decreases) significantly with in-plane tensile (compressive) strain, which agrees qualitatively with density …

Effect Of Spalled Particles Thermal Degradation On A Hypersonic Flow Field Environment, Raghava S. C. Davuluri, Huaibao Zhang, Alexandre Martin

Mechanical Engineering Faculty Publications

Two-way coupling is performed between a spallation code and a hypersonic aerothermodynamics CFD solver to evaluate the effect of spalled particles on the flow field. Time accurate solutions are computed in argon and air flow fields. A single particle simulations and multiple particles simulations are performed and studied. The results show that the carbon vapor released by spalled particles tend to change the composition of the flow field, particularly the upstream region of the shock.

Methane Emissions As Energy Reservoir: Context, Scope, Causes And Mitigation Strategies, Xiaoli Chai, David J. Tonjes, Devinder Mahajan

Technology & Society Faculty Publications

Methane (CH4) is now considered a bridge fuel between present fossil (carbon) economy and desired renewables and this energy molecule is projected to play an important role in the global energy mix well beyond 2035. The atmospheric warming potential of CH4 is 28-36 times, when averaged over a 100-year period, that of carbon dioxide (CO2) and this necessitates a close scrutiny of global CH4 emissions inventory. As the second most abundant greenhouse gas (GHG), the annual global CH4 emissions were 645 million metric tons (MMT), accounting for 14.3% of the global anthropogenic GHG emissions. Of this, five key anthropogenic sources: …

New Approaches To Chalcogenide Materials For Thermoelectrics: Lead Telluride-Based Nanostructures And Facile Synthesis Of Tetrahedrite And Doped Derivatives, Derak Justin James

Wayne State University Dissertations

The overall purpose of this work is to address several of the roadblocks to use of thermoelectric materials for generation of electricity, namely inefficient processing of materials and low performance, commonly rated by the figure of merit, ZT=T2/tot. The ZT includes  as the Seebeck coefficient,  as electrical resistivity, T as the average temperature, and tot as total thermal conductivity. tot is the sum of electronic charge carrier (C) and lattice (L) contributions to thermal conductivity. Attempts to increase ZT in the literature to values >1 have focused on decreasing the thermal conductivity via nanostructuring or optimizing the electrical …

Novel Approaches For Assessment Of Copper Toxicity: Fast Scan Cyclic Voltammetry And Optical Bioassays, Annette R. Tremonti

Wayne State University Dissertations

Anthropogenic activities negatively impact fresh water ecosystems through toxic contaminants that are released into the environment. Copper (Cu) is a water contaminant that is fundamentally persistent once introduced into the environment that has the potential for bioaccumulation. Although Cu toxicity has been studied for decades, there is still a continuing problem with new sources and pathways. New approaches are needed to understand distribution and transport of Cu and its potential for complex biological impacts beyond the simple assessment of lethality. Several novel approaches were used in this research project to advance our understanding of Cu toxicity, including fast scan cyclic …

New Chemistry For The Growth Of First-Row Transition Metal Films By Atomic Layer Deposition, Joseph Peter Klesko

Wayne State University Dissertations

Thin films containing first-row transition metals are widely used in microelectronic, photovoltaic, catalytic, and surface-coating applications. In particular, metallic films are essential for interconnects and seed, barrier, and capping layers in integrated circuitry. Traditional vapor deposition methods for film growth include PVD, CVD, or the use of plasma. However, these techniques lack the requisite precision for film growth at the nanoscale, and thus, are increasingly inadequate for many current and future applications. By contrast, ALD is the favored approach for depositing films with absolute surface conformality and thickness control on 3D architectures and in high aspect ratio features. However, the …

Europium(Ii)-Containing Complexes For Responsive Magnetic Resonance Imaging, Levi Alexander Ekanger

Wayne State University Dissertations

The research projects described in this dissertation are focused on studying the oxidation of EuII-containing complexes within the context of responsive MRI. Prior to this research, EuII had not been explored within the context of oxidation-responsive MRI nor had the use of this ion been reported in vivo. The results of these studies enable predictions about the oxidation-responsive behavior of EuII-containing complexes in vitro and in vivo.

The EuII-containing cryptate 1.33 was used to evaluate EuII-based positive contrast enhancement after intravenous, intraperitoneal, and subcutaneous injections. The transitory behavior of the positive contrast enhancement correlated with reported levels of oxygenation and …

The Dawn Of New Quantum Dots: Synthesis And Characterization Of Ge1-Xsnx Nanocrystals For Tunable Bandgaps., Richard J. Esteves

Theses and Dissertations

Ge_1-xSn_x alloys are among a small class of benign semiconductors with composition tunable bandgaps in the near-infrared spectrum. As the amount of Sn is increased the band energy decreases and a transition from indirect to direct band structure occurs. Hence, they are prime candidates for fabrication of Si-compatible electronic and photonic devices, field effect transistors, and novel charge storage device applications. Success has been achieved with the growth of Ge_1-xSn_x thin film alloys with Sn compositions up to 34%. However, the synthesis of nanocrystalline alloys has proven difficult due to larger discrepancies (~14%) in …

Tio2-Based Nanomaterials For Advanced Environmental And Energy-Related Applications, Xujie Lü, Baoyu Xia, Yefeng Yang, Hao Tang

Physics Faculty Publications

No abstract provided.

Drying Methods For The Fabrication Of Polymer Foam Material, Dalton Echard

Theses and Dissertations

This is a report on the study of the drying of nanoporous polymer foam material fabricated by photolithogtaphic methods. Three drying methods were employed, which were air drying, supercritical drying and freeze drying. After fabrication and drying, physical properties of the polymer foams were measured. These measurements included density of the material, Young’s modulus, surface area, and the shape of the skeletal particles. The measurements determined the effect of the polymer concentration and the effect of drying methods. It was determined that polymer concentration had a much larger effect on the properties of the materials than the drying method.

Degradation And Exciton Energy Transfer Studies In Single-Walled Carbon Nanotube Bundles, Abhishek Gottipati

Legacy Theses & Dissertations (2009 - 2024)

Single walled carbon nanotubes (SWNTs) due to their unique optical behavior, large surface area, robust mechanical strength and electrical properties make them one of the ideal candidates for sensing and opto-electronic applications. In this work, we explore the energy transfer (exciton energy transfer-EET) phenomena occurring between nanotubes in bundles, using resonance Raman spectroscopy.

Enhanced Corrosion Protection And Biocompatibility Of A Plga-Silane Coating On Az31 Mg Alloy For Orthopaedic Applications, Sankalp Agarwal, Muhammad Morshed, Marie-Noelle Labour, David Hoey, Brendan Duffy, James Curtin, Swarna Jaiswal

Articles

This paper reports a multi-step procedure to fabricate a novel corrosion resistant and biocompatible PLGA-silane coating on the magnesium (Mg) alloy AZ31. The first step involves alkaline passivation followed by dip coating in a methyltriethoxysilane (MTES) and tetraethoxysilane (TEOS) mixture to produce a cross-linked siloxane coating. The second step is to impart an amine functionalization to the silane modified surface by using 3-aminopropyl-triethoxy silane (APTES) for promoting adhesion of the acid terminated poly-(lactic-co-glycolic) acid (PLGA) as a final coating step. Static contact angle measurements, Fourier transform infrared spectroscopy and scanning electron microscopy analysis confirmed the successful assembly of coatings on …

Targeted Delivery Of Nrf2 Sirna Using Modular Polymeric Micellar Nanodelivery System For Efficient Target Gene Knockdown In Hepatocellular Carcinoma, Shaimaa Mohamed Ibrahim Yousef

Wayne State University Theses

Tumor selective drug delivery as well as chemotherapy associated multi drug resistance (MDR) pose tremendous hurdles for effective cancer therapy. In this regard, designing multifunctional nanocarriers loaded with drug/gene payloads and engineered with tumor targeting ligands can serve as a modular platform for targeted drug/gene delivery. In this study we undertook the synthesis of a self-assembling block copolymer constructed using poly(styrene-co-maleic anhydride, partial iso-octyl ester) (SMAPIE) and branched polyethylenimine (PEI) as building blocks and evaluated its micelle forming ability, siRNA complexation and siRNA delivery potentials. In addition, we engineered galactosamine decorated nanomicelles using modular “click” chemistry based approaches for evaluating …

Uv Light-Induced Aggregation Of Titania Submicron Particles, Can Zhou, Yashar Bashirzadeh, Timothy A. Bernadowsky Jr., Xiaoyu Zhang

Mechanical & Aerospace Engineering Faculty Publications

In this study, aggregation of TiO₂ (rutile and anatase) submicron particles in deionized (DI) water under ultra-violet (UV) light irradiation was investigated. While no aggregation was observed in the dark, rutile and anatase submicron particles started aggregating upon application of UV light and ceased aggregation in about 2 and 8.4 h, respectively. It has been demonstrated that UV light directly mitigated the particle mobility of TiO₂, resulting in a neutralization effect of the Zeta potential. It was also observed that rutile particles aggregated much faster than anatase particles under UV radiation, indicating that the Zeta potential of …

Carinata Fame Production Process And Biofuel Oxidation, Benoit Kindo

Honors College Theses

In this experiment, the contribution of a standard production method for biofuels on their oxidative stability was investigated. Peroxide values were measured at different steps of the production process of Brassica carinata and peanut-based biofuels. The washing and drying steps in this production method showed significant increases in peroxide values for both biofuels and was identified as a major contributor of biofuel oxidation. Further analyses of the physical and thermal properties showed a more pronounced affect in the biofuel from Bassica carinata, and indicated an unusual composition much higher in saturated fatty acids much longer than those found in peanut. …

Effects Of Citric Acid Coated And Uncoated Cerium Oxide Nanoparticles In Tomato (Solanum Lycopersicum) Plants, Ana Cecilia Barrios

Open Access Theses & Dissertations

This research was performed to examine the physiological and biochemical effects of bare (nCeO2) and citric acid coated (nCeO2+CA) cerium oxide nanoparticles in tomato (Solanum lycopersicum). Plants were germinated and grown to full maturity in soil amended with 0-500 mg/kg and periodically analyzed using ICP-OES/MS and other spectroscopic and biochemical techniques. Although Ce in tissues increased as the external nCeO2 increased, there were no visible signs of toxicity. In mature plants, nCeO2 induced developmental changes and altered nutritional quality (essential elements) in fruits. On the other hand, nCeO2+CA affected fruit carbohydrate composition (sugars and starch). This study gives insights on …

Improving The Engineering Properties Of Pla For 3d Printing And Beyond, Carmen R. Rocha

Open Access Theses & Dissertations

Additive manufacturing (AM), now more commonly known as 3D printing, has been classified as efficient, fast, and practical in the prototyping sector of product development. In the work presented here, we will use one of the AM techniques known as Material extrusion 3D printing (ME3DP), which has all the advantages of AM. However, one of the biggest challenges facing ME3DP technologies is the limitation of the range of materials used by this technique. Acrylonitrile butadiene styrene (ABS) and poly-lactic acid (PLA) are currently the most common thermoplastics materials used in ME3DP because of their ability to melt and be reprocessed. …

Enabling Method To Design Versatile Biomaterial Systems From Colloidal Building Blocks, Shalini Saxena, L. Andrew Lyon

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Development of materials with fine spatial control over topographical, mechanical, or chemical features has been investigated for a variety of applications. Here we present a method to fabricate an array of polyelectrolyte constructs including two-dimensionally and three-dimensionally patterned assemblies using both compressible and incompressible colloidal building blocks. This method eliminates prior constraints associated with specific chemistries, and can be used to develop modular, multi-component, patterned assemblies. In particular, development of constructs were investigated using microgels, which are colloidally stable hydrogel microparticles, polystyrene (PS) beads, and PS-microgel core-shell building blocks in conjunction with the polycation poly(ethyleneimine) (PEI). The topography, mechanical properties, …

Prediction Of Metal Remobilization From Sediments Under Various Physical/ Chemical Conditions “Design Of Experiments Cd, Co And Pb”, Eid A. Alkhatib, Trey Chabot, Danielle Grunzke

Chemistry & Physics Faculty Publications

The metal partition coefficient Kd (L/kg) is the ratio of sorbed metal concentration on the solid phase m (mg/kg) to the dissolved metal concentration at equilibrium. The behavior of metals in surface water is complex and their partition coefficients can be impacted by many factors. Organic matter (OM) content in sediments, pH and salinity, are factors that may influence speciation and partitioning of metals. In this study, the partitioning coefficient of three metals (Cd, Co and Pb) under different levels of salinity, pH, and OM content were examined. A series of factorial experiments were evaluated in which three levels of …

Tracking Silver, Gold, And Titanium Dioxide Nanoparticles Through Drinking Water Systems By Single Particle - Inductively Coupled Plasma - Mass Spectrometry, Ariel Renee Donovan

Masters Theses

"Single particle (SP)-ICP-MS methods were developed to characterize and quantify Ti-containing, titanium dioxide, silver, and gold NP concentration, size, size distribution and dissolved metal element concentration in surface water and treated drinking water. The effectiveness of conventional drinking water treatments (including lime softening, alum coagulation, filtration, and disinfection) to remove NPs from surface water was evaluated using six-gang stirrer jar test simulations. Six-gang stirrers were used to simulate drinking water treatments including lime softening, alum coagulation, powdered activated carbon sorption, filtration, and disinfection by free chlorine. Lime softening effectively removed most nanoparticles added. Source and drinking waters from three large …

The Role Of Microbial Exopolymers In Determining The Fate Of Oil And Chemical Dispersants In The Ocean, Antonietta Quigg, Uta Passow, Wei-Chun Chin, Chen Xu, Shawn Doyle, Laura Bretherton, Manoj Kamalanathan, Alicia K. Williams, Jason B. Sylvan, Zoe V. Finkel, Anthony H. Knap, Kathleen A. Schwehr, Saijin Zhang, Luni Sun, Terry L. Wade, Wassim Obeid, Patrick G. Hatcher, Peter H. Santschi

Chemistry & Biochemistry Faculty Publications

The production of extracellular polymeric substances (EPS) by planktonic microbes can influence the fate of oil and chemical dispersants in the ocean through emulsification, degradation, dispersion, aggregation, and/or sedimentation. In turn, microbial community structure and function, including the production and character of EPS, is influenced by the concentration and chemical composition of oil and chemical dispersants. For example, the production of marine oil snow and its sedimentation and flocculent accumulation to the seafloor were observed on an expansive scale after the Deepwater Horizon oil spill in the Northern Gulf of Mexico in 2010, but little is known about the underlying …

Anticancer, Biophysical And Computational Investigations Of Half-Sandwich Ruthenium(Ii) Thiosemicarbazone Complexes: The Effect Of Arene Versus Thiacrown Face-Cap, Floyd A. Beckford, Alyssa Stott, P. Canisius Mbarushimana, Marc-Andre Leblanc, Kinsey Hall, Samantha Smith, Jimmie L. Bullock, Dennis J. Houghton, Alvin A. Holder, Nikolay Gerasimchuk, Antonio Gonzalez-Sarrías

Chemistry & Biochemistry Faculty Publications

A series of half-sandwich ruthenium complexes, two containing an arene face-cap and the other a thiacrown ether face-cap were synthesized to investigate the necessity of the arene for anticancer activity in this class of compounds. The complexes are formulated as [(h⁶-p-cymene)Ru(dmabTSC)Cl]PF₆, [(h⁶-benzene)Ru(dmabTSC)Cl]PF₆ (arene complexes), and [([9]aneS₃(dmabTSC)Cl]PF₆ (dmabTSC = dimethylaminobenzaldehye thiosemicarbazone). It was observed that none of the complexes showed good anticancer activity in vitro against HCT-116 and Caco-2 (colon adenocarcinoma) cells. All three complexes can bind strongly to calf-thymus DNA with binding constants on the order of 10 …