Chemistry Commons^™

Recent Progress Of Electrochemiluminescence Sensors Based On Electrically Heated Electrode, Hui-Fang Zhang, Yi-Ting Chen, Fang Luo, Zhen-Yu Lin, Guo-Nan Chen

Journal of Electrochemistry

Electrochemiluminescence (ECL) has broad application in the fields of environmental monitoring and biological analysis due to its intrinsic advantages such as excellent versatility, good detection sensitivity, and high specificity. The intensity of ECL can be influenced by temperature variation in the ECL quantum efficiency and the rate of electrochemical reaction. However, traditional temperature control is commonly realized through bulk solutions heating, which is complicated and unfavorable for detection when the volatile and thermally unstable materials existed. In order to address these problems, electrically heated electrodes are used to adjust the temperature desired. The major character of this technique lies in …

Application Of Nanomaterials In The Detection Of Volatile Organic Compounds In Exhaled Breath For Cancer Diagnosis, Wan-Qiao Bai, Xue-Zhi Qiao, Tie Wang

Journal of Electrochemistry

Volatile organic compounds (VOCs) generated in human body can reflect one’s health state, and numerous diseases are identified by some VOCs biomarkers. More recently, analyses of VOCs biomarkers from exhaled breath have turned into a research frontier worldwide because it offers a noninvasive way for diseases diagnosis. Various kinds of nanomaterials are used to enhance the performance of sensing techniques, and play an essential role in miniaturization detection. In this review, several kinds of nanomaterials (metallic, metal oxide, carbon-based, composites and MOFs-based materials) used in various VOCs detection methods, especially in VOCs sensors are summarized. Learning from the successful utilization …

Sensitive Photoelectrochemical Assay Of Nucleic Acids Based On Catalytic Hairpin Assembly And Ru(Nh3)63+, Ya-Min Fu, Xiao-Xia Yan, Xiao-Hua Zhang, Jin-Hua Chen

Journal of Electrochemistry

A simple “signal-on” photoelectrochemical (PEC) sensing platform for sensitive assay of nucleic acids was developed by coupling catalytic hairpin assembly (CHA) signal amplification strategy with Ru(NH₃)₆³⁺. Herein, cadmium sulfide (CdS) was deposited on the TiO₂/indium tin oxide (ITO) electrode by a method of successive ionic layer adsorption and reaction (SILAR), serving as one kind of photoelectric material to broaden absorption range of TiO₂ and to improve the photoelectric conversion efficiency. Thereafter, the capture DNA (C-DNA) was immobilized on the CdS/TiO₂/ITO electrode. Simultaneously, Au-hairpin DNA probe 1 (Au-HP1) and hairpin DNA …

A Facile Strategy For Two-Step Fabrication Of Gold Nanoelectrode For In Vivo Dopamine Detection, Li-Hao Guan, Chao Wang, Wang Zhang, Yu-Lu Cai, Kai Li, Yu-Qing Lin

Journal of Electrochemistry

In vivo monitoring neurochemicals with microelectrode is invasive and the damage to brain tissue may inevitably cause disturbance signals physiologically to the measurement. It is of great importance to reduce the electrode size and to decrease the damage. This study demonstrates a novel nanoelectrode preparation methodology for in vivo monitoring dopamine (DA) fluctuation in the living brain of rats with high dependability. The fabrication process of the gold nanoelectrode involving a few minutes consists of only two steps: 1) growing gold nanoseeds on surface of tip of glassy capillary by ion sputtering; 2) wet depositing a continuous conductive gold film …

Graphene-Like Secondary-Laser-Etched Polyimide Film Decorated With CuXO Nanocomposites: A Novel Electrode Substrate For Non-Enzymatic Glucose Sensors, Wan-Lin Dai, Zhi-Wei Lu, Jian-Shan Ye

Journal of Electrochemistry

In this work, a novel electrode substrate with graphene-like surface and Cu_xO nanocomposites derived from secondary-laser-etched polyimide (SLEPI) film was synthesized and applied in non-enzymatic glucose detection for the first time. Characterizations indicate that the as-prepared SLEPI/Cu_xO film electrode (SLEPI/Cu_xO-FE) possessed huge surface area, plentiful active sites and excellent electrocatalytic performance. The obtained sensor exhibited the high sensitivity and selectivity for glucose determination with a linear range of 0.05 mmol·L^-1 to 3 mmol·L^-1 and a detection limit of 1.72 μmol·L^-1 (S/N=3), which provides a simple, flexible and low-cost electrochemical sensor for …

Preparation And Electrocatalytic Oxygen Reduction Performance Of Self-Doped Sludge-Derived Carbon, Ya-Li Ye, Wei-Ming Feng, Ge Li, Zhen-Chao Lei, Chun-Hua Feng

Journal of Electrochemistry

The development of low-cost, high-performance cathode catalysts is critical for practical application of fuel cells. Here, the N, P-doped porous graphene-like carbon with outstanding oxygen reduction reaction (ORR) performance was synthesized by pyrolysis of surplus sludge, which functioned as a self-doped, self-activated, and self-templated precursor by acclimation with continuous feedings of phenol. The results show that the amounts of microorganisms were enriched after acclimation, with increasing contents of N, P, Fe, as well as C atoms. The increasing pyrolysis temperature resulted in the formation of an ordered graphitic structure, however, the excessively high temperature induced the drop in the amounts …

Using A Balloon-Launched Unmanned Glider To Validate Real-Time Wrf Modeling, Travis J. Schuyler, S. M. Iman Gohari, Gary Pundsack, Donald Berchoff, Marcelo I. Guzman

Chemistry Faculty Publications

The use of small unmanned aerial systems (sUAS) for meteorological measurements has expanded significantly in recent years. SUAS are efficient platforms for collecting data with high resolution in both space and time, providing opportunities for enhanced atmospheric sampling. Furthermore, advances in mesoscale weather research and forecasting (WRF) modeling and graphical processing unit (GPU) computing have enabled high resolution weather modeling. In this manuscript, a balloon-launched unmanned glider, complete with a suite of sensors to measure atmospheric temperature, pressure, and relative humidity, is deployed for validation of real-time weather models. This work demonstrates the usefulness of sUAS for validating and improving …

Ligand Selectivity In The Recognition Of Protoberberine Alkaloids By Hybrid-2 Human Telomeric G-Quadruplex: Binding Free Energy Calculation, Fluorescence Binding, And Nmr Experiments, Nanjie Deng, Junchao Xia, Lauren Wickstrom, Clement Lin, Kaibo Wang, Peng He, Yunting Yin, Danzhou Yang

Publications and Research

The human telomeric G-quadruplex (G4) is an attractive target for developing anticancer drugs. Natural products protoberberine alkaloids are known to bind human telomeric G4 and inhibit telomerase. Among several structurally similar protoberberine alkaloids, epiberberine (EPI) shows the greatest specificity in recognizing the human telomeric G4 over duplex DNA and other G4s. Recently, NMR study revealed that EPI recognizes specifically the hybrid-2 form human telomeric G4 by inducing large rearrangements in the 50-flanking segment and loop regions to form a highly extensive four-layered binding pocket. Using the NMR structure of the EPI-human telomeric G4 complex, here we perform molecular dynamics free …

Nanogels And Microgels: From Model Colloids To Applications, Recent Developments, And Future Trends, Mattias Karg, Andrij Pich, Thomas Hellweg, Todd Hoare, L. Andrew Lyon, J. J. Crassous, Daisuke Suzuki, Rustam A. Gumerov, Stefanie Schneider, Igor I. Potemkin, Walter Richtering

Engineering Faculty Articles and Research

Nanogels and microgels are soft, deformable, and penetrable objects with an internal gel-like structure that is swollen by the dispersing solvent. Their softness and the potential to respond to external stimuli like temperature, pressure, pH, ionic strength, and different analytes make them interesting as soft model systems in fundamental research as well as for a broad range of applications, in particular in the field of biological applications. Recent tremendous developments in their synthesis open access to systems with complex architectures and compositions allowing for tailoring microgels with specific properties. At the same time state-of-the-art theoretical and simulation approaches offer deeper …

Reduction Of Amine Emissions From An Aqueous Amine Carbon Dioxide Capture System Using Charged Colloidal Gas Aphrons, Xiaobing Li, Jesse G. Thompson, Kunlei Liu

Center for Applied Energy Research Faculty Patents

The present invention includes a system and process to reduce amine mist emissions (or MEA) from carbon capture systems using colloidal gas aphrons (CGA), and includes a method for separating and recovering an amine solvent (e.g., in the form of entrained droplets/mist and/or fine aerosol particles) from a carbon dioxide scrubbed flue gas stream exiting a carbon capture system (e.g., oil-fired power plants, coal-fired power plants, and/or natural gas combined cycle plants).

Fluoride Removal From Water Using A 3d Printed Calcium Carbonate Filter, Sophia Bakar, David Kahler, Benjamin S. Goldschmidt

Undergraduate Research and Scholarship Symposium

Groundwater containing high concentrations of fluoride is the most common source of drinking water in rural areas in parts of east Africa, India, and China. The elevated levels of fluoride cause skeletal and dental fluorosis, which is the weakening and decay of bone structures due to the leeching of calcium from the body as calcium and fluoride bond by the process of adsorption. Over 150 million people are suffering from some form of fluorosis due to the consumption of groundwater. Calcium carbonate has been demonstrated to influence fluoride removal in several forms. To make fluoride removal a cost-effective and user-friendly …

A Dual Nanostructured Approach To Sers Amenable To Large-Scale Production, Kory Brian Castro

Chemistry & Biochemistry Theses & Dissertations

A SERS device was made using a dual-nanostructured surface comprised of silver nanoparticle and silver nanowires. The ability of each nanostructure to produce a uniform surface was characterized and the surface-enhanced Raman scattering (SERS) response of the resulting surfaces were examined using the reporter molecule 4-aminothiolphenol (ATP) and a 638 nm excitation laser.

A synthetic method was developed to produce silver nanowires with lengths of ~20 μm and diameters of ~100 nm with a narrow size distribution. The method utilized a simple, one-pot synthesis that is amenable to large-scale production. A selective precipitation method was used to the isolate the …

The Effects Of Organic And Inorganic Nanoparticles On Bacterial Deactivation, Lauren Cooper

Mahurin Honors College Capstone Experience/Thesis Projects

Antibacterial resistance is one of the greatest problems in modern medicine, as healthcare professionals are experiencing more and more difficulty in providing effective care. As such, alternative methods of treatment are needed in order to overcome this issue. One recently proposed method of alternative treatment is photodynamic therapy. Photodynamic therapy is a light-based method of treatment that utilizes (1) a photosensitizing agent, (2) light, (3) produced oxygen species. When the photosensitizing agent is injected into an infected region of interest and then irradiated with a certain wavelength of light, the agent is photoactivated and begins to produce harmful forms of …

Protein-Polymer Conjugates Synthesized Using Water-Soluble Azlactone-Functionalized Polymers Enable Receptor-Specific Cellular Uptake Toward Targeted Drug Delivery, Julia S. Kim, Allison R. Sirois, Analia J. Vazquez Cegla, Eugenie Jumai'an, Naomi Murata, Maren E. Buck, Sarah J. Moore

Chemistry: Faculty Publications

Conjugation of proteins to drug-loaded polymeric structures is an attractive strategy for facilitating target-specific drug delivery for a variety of clinical needs. Polymers currently available for conjugation to proteins generally have limited chemical versatility for subsequent drug loading. Many polymers that do have chemical functionality useful for drug loading are often insoluble in water, making it difficult to synthesize functional protein–polymer conjugates for targeted drug delivery. In this work, we demonstrate that reactive, azlactone-functionalized polymers can be grafted to proteins, conjugated to a small-molecule fluorophore, and subsequently internalized into cells in a receptor-specific manner. Poly(2-vinyl-4,4-dimethylazlactone), synthesized using reversible addition–fragmentation chain …

Tin Assisted Fully Exposed Platinum Clusters Stabilized On Defect-Rich Graphene For Dehydrogenation Reaction, Jiayun Zhang, Yuchen Deng, Xiangbin Cai, Yunlei Chen, Mi Peng, Zhimin Jia, Zheng Jiang, Pengju Ren, Siyu Yao, Jinglin Xie, Dequan Xiao, Xiao-Dong Wen, Ning Wang, Hongyang Liu, Ding Ma

Chemistry and Chemical Engineering Faculty Publications

Tin assisted fully exposed Pt clusters are fabricated on the core-shell nanodiamond@graphene (ND@G) hybrid support (a-PtSn/ND@G). The obtained atomically dispersed Pt clusters, with an average Pt atom number of 3, were anchored over the ND@Gsupport by the assistance of Sn atoms as a partition agent and through the Pt-C bond between Pt clusters and defect-rich graphene nanoshell. The atomically dispersed Pt clusters guaranteed a full metal availability to the reactants, a high thermal stability, and an optimized adsorption/desorption behavior. It inhibits the side reactions and enhances catalytic performance in direct dehydrogenation of n-butane at a low temperature of 450 °C, …

Deswelling Induced Morphological Changes In Dual Ph And Temperature Responsive Ultra-Low Crosslinked Poly (N-Isopropyl Acrylamide)-Co-Acrylic Acid Microgels, Molla R. Islam, Maddie Tumbarello, L. Andrew Lyon

Engineering Faculty Articles and Research

Poly(N-isopropylacrylamide) microgels prepared without exogenous cross-linker are extremely “soft” as a result of their very low cross-linking density, with network connectivity arising only from the self-crosslinking of pNIPAm chains. As a result of this extreme softness, our group and others have taken interest in using these materials in a variety of bioengineering applications, while also pursuing studies of their fundamental properties. Here, we report deswelling triggered structural changes in poly(N-isopropylacrylamide-co-acrylic acid) (ULC10AAc) microgels prepared by precipitation polymerization. Dynamic light scattering suggests that the deswelling of these particles not only depends on the collapse of …

Photocatalytic Degradation Of Profenofos And Triazophos Residues In The Chinese Cabbage, Brassica Chinensis, Using Ce-Doped Tio2, Xiangying Liu, You Zhan, Zhongqin Zhang, Lang Pan, Lifeng Hui, Kailin Liu, Xuguo Zhou, Lianyang Bai

Entomology Faculty Publications

Pesticides have revolutionized the modern day of agriculture and substantially reduced crop losses. Synthetic pesticides pose a potential risk to the ecosystem and to the non-target organisms due to their persistency and bioaccumulation in the environment. In recent years, a light-mediated advanced oxidation processes (AOPs) has been adopted to resolve pesticide residue issues in the field. Among the current available semiconductors, titanium dioxide (TiO₂) is one of the most promising photocatalysts. In this study, we investigated the photocatalytic degradation of profenofos and triazophos residues in Chinese cabbage, Brassica chinensis, using a Cerium-doped nano semiconductor TiO₂ (TiO …

Conducting Polymer Based Gel Electrolytes For Ph Sensitivity, Aditya Jagannath Kashyap

USF Tampa Graduate Theses and Dissertations

The evaluation of concentration of ions and molecules with the help of biosensors have been regarded as an emerging technology. Bio and chemical sensors have a variety of applications in the field of medicine, military, environmental and food industries alike. With an estimated investment growth of over 4.31% in the development of pH sensors in the next five year, the objective of a developing a robust measurement system is all the more required. The scope of this research is to evaluate the ability of conducting polymer-based gel electrolytes for pH sensitivity, as a function of the transistor characteristics using an …

Fracture Toughness And Fatigue Crack Growth Rate Characterization Of Inconel 718 Formed By Laser Powder Bed Fusion, Charles C. Hohnbaum

Theses and Dissertations

Continuing improvement in the field of AM of metals provides the opportunity for direct fabrication of aerospace parts. AM was once used in large part for rapid prototyping but improvements in technology and increases in the knowledge base of AM materials has provided the opportunity for manufacture of AM parts for operational use. The ability to create low numbers of unique parts without having to invest in expensive tooling provides great economic incentive to utilize this technique. IN718 is the most common high temperature alloy used in the aerospace industry and lends itself readily to formation by LPBF. The superior …

The Effects Of Reactant Concentration And Air Flow Rate In The Consumption Of Dissolved O2 During The Photochemistry Of Aqueous Pyruvic Acid, Alexis J. Eugene, Marcelo I. Guzman

Chemistry Faculty Publications

The sunlight photochemistry of the organic chromophore pyruvic acid (PA) in water generates ketyl and acetyl radicals that contribute to the production and processing of atmospheric aerosols. The photochemical mechanism is highly sensitive to dissolved oxygen content, [O₂(aq)], among other environmental conditions. Thus, herein we investigate the photolysis (λ ≥ 305 nm) of 10–200 mM PA at pH 1.0 in water covering the relevant range 0 ≤ [O₂(aq)] ≤ 1.3 mM. The rapid consumption of dissolved oxygen by the intermediate photolytic radicals is monitored in real time with a dissolved oxygen electrode. …

Control Strategies For Multi-Evaporator Vapor Compression Cycles, Sunderlin D. Jackson

Theses and Dissertations

Next-generation military aircraft must be able to handle highly transient thermal loads that exceed the ability of current aircraft thermal subsystems. Vapor compression cycle systems are a particular refrigeration technology that is an attractive solution for dealing with this challenge, due primarily to their high efficiency. However, there are several barriers to realizing the benefits of vapor cycles systems for controlling thermal loads in military aircraft. This thesis focuses on addressing the challenge of controlling vapor cycles in the presence of highly transient evaporator heat loads. Specifically, a linear quadratic regulator (LQR) is designed for a simple vapor cycle system, …

Creep Of Nextel 720/Alumina Ceramic Matrix Composite With Diamond-Drilled Effusion Holes At 1200°C In Air And In Steam, Megan L. Harkins

Theses and Dissertations

A recent study evaluated tensile stress-strain and tensile creep behavior of an oxide-oxide composite (Nextel™720/alumina) with laser-drilled effusion holes at 1200°C. It was determined that the presence of laser-drilled holes degraded the mechanical properties and performance of the CMC as a result of damage caused to the composite microstructure by the laser drilling process. Based on these results, the present effort sought to assess the effects of diamond-drilled holes on the mechanical behavior of this CMC. Tensile properties of the N720/A composite at 1200°C in laboratory air were unaffected by the presence of an array of 17 diamond-drilled effusion holes. …

Process Parameter Development Of Additively Manufactured Af9628 Weapons Steel, Erin M. Hager

Theses and Dissertations

The manufacture of components in Additive Manufacturing processes is limited by the range of materials available. Qualification of materials for Additive Manufacturing is time intensive, and is often specific to a single type of machine. In this study, an approach to selecting power, speed, and hatch spacing values for a newly powderized material, AF9628 weapons steel, is described that results in highly dense (>99.9%) parts on an MLab 200R Cusing. Initial power and speed values used in a weld track study were selected based on a survey of parameters used on similar materials, with a focus on the energy …

Modeled Affinity Constants For Phosphorus Adsorption And Desorption Due To Saltwater Intrusion, Yasemin Taşcı

USF Tampa Graduate Theses and Dissertations

It is important to understand the processes that regulate phosphorus (P) fluxes to coastal environments, because P is an important nutrient in coastal ecosystems. Phosphorus adsorbs to the surface of minerals in sediment and bedrock, and an influx of seawater can cause some of that P to desorb, raising the P concentration of ambient water. Although seawater-induced P desorption is thought to be an important source of P to coastal environments, the chemical reactions that underlie it have not been established. Previous work provides some relevant surface reactions and associated affinity constants between various aqueous P species and the surface …

Current Status And Prospect Of Battery Configuration In Li-S System, Jia-Hang Chen, Hui-Jun Yang, Cheng Guo, Jiu-Lin Wang

Journal of Electrochemistry

Commercial lithium-ion batteries (LIBs) are incapable of satisfying the increasing demand for emerging electronic devices due to their limited energy density. Among the next-generation batteries, lithium-sulfur (Li-S) batteries are becoming a promising energy-storage system due to their high theoretical energy density and natural abundance of sulfur. However, the shuttle of soluble polysulfide intermediates between two electrodes, as well as the problem on Li metal anode,lower the utilization of active material and lead to the loss of specific capacity and rapid capacity fading. All the above challenges limit the further application of Li-S batteries. Recently, various novel battery configurations have been …

Recent Progress On Tio2-Based Anode Materials For Sodium-Ion Batteries, Si-Tian Lian, Jian-Shuai Lv, Qiang Yu, Guang-Wu Hu, Zhuo Chen, Liang Zhou, Li-Qiang Mai

Journal of Electrochemistry

Titanium dioxide (TiO₂) represents a stable, low-cost, and nontoxic anode material for sodium-ion batteries (SIBs). However, the low electrical conductivity limits its electrochemical activity (specific capacity) and rate capability, hindering its widespread applications. In this article, we show that different crystal forms of TiO₂ have different pore structures, resulting in the distinct sodium storage capacities. Accordingly, the article introduces how TiO₂ microstructures influence sodium storage. The nanoparticle structure can improve the rate performance of the material due to its short ion diffusion distance, and the internal cavity of the hollow structure is beneficial to cycle stability. …

Recent Progress In Vanadium-Based Electrode Materials, Meng-Lei Sun, Da-Qi Zhang, Jin-Kui Feng, Jiang-Feng Ni

Journal of Electrochemistry

It is an important solution to solve energy storage problems by developing inexpensive and safe lithium-ion and sodium-ion batteries with superior performance. Vanadium-based electrode materials are promising electrode materials because of diversified chemical valences, open structures and high theoretical capacities. In the past few years, vanadium-based electrode materials such as oxides, sulfides, and phosphates have achieved a considerable development in the battery field, It is,  therefore, necessary to summarize their recent research progress. In this review, we particularly highlight the key challenges that are facing in the application of vanadium materials, such as low ion diffusion coefficient and poor structural …

Recent Progress In Key Materials For Room-Temperature Sodium-Ion Batteries, Fan-Fan Wang, Xiao-Bin Liu, Long Chen, Cheng-Cheng Chen, Yong-Chang Liu, Li-Zhen Fan

Journal of Electrochemistry

Sodium-ion batteries (SIBs) have attracted tremendous attention in large-scale energy storage applications due to their resource advantages. However, Na+ is larger and heavier than Li+, which will limit its reversible reaction with the electrode materials and result in poor electrochemical performance. Thus, developing stable and high-efficiency electrode materials is the key to promoting the practical application of SIBs. Furthermore, the optimization of electrolyte is essential for the construction of high-safety and long-lifespan SIBs. In this review, we mainly summarize the recent advancements of electrode materials and electrolytes for room-temperature SIBs and discuss their challenges and possible resolution strategies. We hope …

Recent Developments In Surface/Interface Modulation And Structure-Performance Relationship Of Cathode Catalysts For Li-Air Batteries, Rui Gao, Jun-Kai Wang, Zhong-Bo Hu, Xiang-Feng Liu

Journal of Electrochemistry

Lithium-air battery has been considered to be one of the most promising secondary battery systems because of its high energy density. However, the sluggish kinetics of the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) on the cathode, and the high overpotential, poor cycle stability and low rate capacity have severely blocked the development and application of Li-air battery. One of the effective strategies to alleviate these issues is to develop cathode catalysts for Li-air batteries. The design and development of bifunctional cathode catalysts with high activity and efficiency on both ORR and OER is highly desired for Li-air …

A Comparative Study Of Pre-Lithiated Hard Carbon And Soft Carbon As Anodes For Lithium-Ion Capacitors, Zhao Li, Xian-Zhong Sun, Wen-Jie Liu, Xiong Zhang, Kai Wang, Yan-Wei Ma

Journal of Electrochemistry

Lithium-ion capacitor (LIC) has emerged to be one of the most promising electrochemical energy storage devices. Presently, activated carbon (AC) is the mostly used cathode material for LIC. Nevertheless, various carbonaceous materials can be used as anode materials, such as hard carbon (HC) and soft carbon (SC). Therefore, HC and SC with different structural and electrochemical characteristics have been investigated as the anode materials of LICs in this work. Compared with the HC electrode, the SC electrode showed higher electronic conductivity and reversible capacity. The rate capabilities of the two carbonaceous materials as a function of coating thickness have been …