Chemistry Commons^™

Ordered Mesoporous Carbon/Graphene/Nickel Foam For Flexible Dopamine Detection With Ultrahigh Sensitivity And Selectivity, Lai-Yu Wang, Xin Xi, Dong-Qing Wu, Xiong-Yu Liu, Wei Ji, Rui-Li Liu

Journal of Electrochemistry

Electro-catalytic reduction is an efficient way to achieve resourcable transformation of CO₂, which is one of the important techniques to solve the global environmental problems originated from excessive CO₂ emission. In this study, a membrane electrode assembly(MEA) type CO₂ electro-reduction electrolytic cell was constucted, which enables CO₂ feeding and real-time KHCO₃ aqueous updating on both sides of the cathode gas diffusion electrode (GDE). By means of the electrolytic cell, effects of KHCO₃ concentration and updating inside the liquid electrolytic chamber on CO₂ electro-reduction activity, production distribution and stability were investigated. The experimental …

Poly(Ethylene Oxide) Based Polymer Electrolytes For All-Solid-State Li-S Batteries, Xue Li, Zheng-Liang Gong

Journal of Electrochemistry

In recent years, research on lithium-sulfur (Li-S) batteries has received much attention because the sulfur positive electrode and the lithium metal negative electrode produce a high theoretical specific capacity (lithium metal ~ 3800 mAh·g^-1, sulfur ~ 1675 mAh·g^-1). In addition, sulfur is considered to be the most promising cathode material for secondary lithium batteries, due to its advantages of low price and environmental friendly. However, the practical application of conventional liquid Li-S batteries is still obstructed by several critical issues, such as lithium ploysulfides shuttle effect, long-term stability of lithium metal anode with organic liquid electrolytes, …

Electrochemical Response Of A Single Wire-Electrode Ac Probe In 3.5wt.% Nacl, Zhen-Wen Zou, Da-Jiang Zheng, Zi-Ming Wang, Guang-Ling Song

Journal of Electrochemistry

In this paper, a recently developed single wire-electrode AC probe technology which does not need a reference or counter electrode was employed to investigate the electrochemical corrosion and sacrificial anode protection behaviors of steel and zinc in 3.5wt.% NaCl. With this simple, fast, reliable and stable probe, the instantaneous corrosion rate and accumulated corrosion loss of carbon steel in 3.5wt.% NaCl were measured, and the results revealed that both were greater than those of zinc. Furthermore, the observed different corrosion behaviors between carbon steel and zinc during the immersion could be caused by their different surface films. With the galvanic …

Synthesis And Raman Study Of Hollow Core-Shell Ni1.2Co0.8P@N-C As An Anode Material For Sodium-Ion Batteries, Jia-Hui Chen, Xiao-Bin Zhong, Chao He, Xiao-Xiao Wang, Qing-Chi Xu, Jian-Feng Li

Journal of Electrochemistry

With the increasing demand for large-scale energy storage, great progress has been made in discovering new advanced energy storage materials. Sodium-ion batteries (SIBs) have attracted much attention in recent years due to their use of abundant sodium resources and their comparable electrochemical capacity to lithium-ion batteries (LIBs). In this paper, we developed novel hollow core-shell Ni-Co bimetallic phosphide nanocubes with N-doped carbon coatings (Ni_1.2Co_0.8P@N-C) as the anode material for SIBs. The material was synthesized through a low-temperature phosphorization method using resorcinol formaldehyde (RF) resin coating with a Ni-Co Prussian blue analogue (PBA) as a template and …

Preparations Of Nano-MnoX/Ti Electrocatalytic Membrane Electrode For Catalytic Oxidation Of Cyclohexane Using Intermittent Electrodeposition, Xue Zhou, Hong Wang, Zhen Yin, Yu-Jun Zhang, Jian-Xin Li

Journal of Electrochemistry

Cyclohexanone and cyclohexanol (KA oil) obtained from highly selective oxidation of cyclohexane (CHA) show important industrial value and application prospects. In this work, the intermittent electrodeposition was developed to prepare nano-MnO_x catalyst loading porous tubular titanium membrane electrode (MnO_x/Ti), which was employed to constitute an electro-catalytic membrane reactor (ECMR) for the oxidation of cyclohexane to produce cyclohexanol and cyclohexanone. The surface morphology, crystal structure and electrochemical property of the catalysts were characterized by FESEM, XRD and electrochemical workstation, respectively. The results show that the catalyst prepared by the intermittent electrodeposition displayed nano-flower-like γ-MnO₂. Compared with …

Stability Studies For A Membrane Electrode Assembly Type Co2 Electro-Reduction Electrolytic Cell, Qing Mao, Bing-Yu Li, Wei-Yun Jing, Jian Zhao, Song Liu, Yan-Qiang Huang, Zhao-Long Du

Journal of Electrochemistry

Electro-catalytic reduction is an efficient way to achieve resourcable transformation of CO₂, which is one of the important techniques to solve the global environmental problems originated from excessive CO₂ emission. In this study, a membrane electrode assembly(MEA) type CO₂ electro-reduction electrolytic cell was constucted, which enables CO₂ feeding and real-time KHCO₃ aqueous updating on both sides of the cathode gas diffusion electrode (GDE). By means of the electrolytic cell, effects of KHCO₃ concentration and updating inside the liquid electrolytic chamber on CO₂ electro-reduction activity, production distribution and stability were investigated. The experimental …

A Simple And Sensitive Aptamer-Based Electrochmical Sensor For Determination Of Aflatoxin B1, Bing Liu, Yao-Shuai Zhao, Yue Qin, Yi Wang, Yan-Jie Zhu, Shuo Wang

Journal of Electrochemistry

Aflatoxin B1 has attracted much attention because of its high toxicity and carcinogenicity, which has become a great concern in food safety. Based on the principle of specific binding between Aflatoxin B1 and its aptamer, an aptamer-based electrochemical sensor had been designed and developed for the determination of minor Aflatoxin B1 contained in grain. The mesoporous carbons were first modified on the surface of the working electrode, and then the gold nanoparticles were on-site electrodeposited at a constant potential. Each modified electrode was characteritised by scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). As a result, the surface area …

Preparation Of Α-Hydroxylated Acetal From 2-Butanone By Indirect Electrooxidation, Hai-Qing Huang, Ye Miao, Xin-Sheng Zhang

Journal of Electrochemistry

Acetoin (3-hydroxy-2-butanone) is an important food spice. As a platform compound, it is widely used in medicine, tobacco, cosmetics, chemical material and other industries. In this paper, α-hydroxylated acetal, an intermediate of acetoin, was prepared from 2-butanone by indirect electrooxidation in the plate and frame electrolytic cell, in which graphite plates were used as both an anode and a cathode, while KOH as an electrolyte and KI as a catalyst. Acetoin could be prepared by hydrolysis in acidic aqueous solution from acetoin intermediate. The effects of current density, electrolyte flow rate between the plates, 2-butanone concentration and electrolysis temperature …

Antimicrobial Strategies For Topical Applications, Kelsey Marie Lopez

LSU Doctoral Dissertations

Bacteria can thrive in diverse environments and are often harmless or beneficial. Bacteria in digestive tracts is one example of beneficial bacteria; however, bacteria can be harmful and when this type proliferates, it can cause infections within hosts. Bacterial infections are easily treated with antibiotics in most cases. However, bacteria are also capable of developing mutations which could cause them to become multi-drug resistant and eventually, “superbugs.” Therefore, the development of novel antimicrobial agents and materials capable of combating drug-resistant bacteria is necessary. Research presented in this dissertation focuses on different strategies for minimizing and preventing topical bacterial infections using …

Degradation Mechanism Of Lini0.83Co0.12Mn0.05O2 Cycled At 45 ℃, Hong-Yun Ma, Xiao-Hui Yao, Meng-Yao Miao, Yang Yi, Shao-Zhong Wu, Jiang Zhou

Journal of Electrochemistry

Nickel-rich layered material has been considered as the most promising one for lithium ion batteries due to its high specific capacity. To further improve the lifetime performance, it is significant to investigate the degradation mechanisms deeply. In this study, the degradation mechanism of NCM811 (LiNi_0.83Co_0.12Mn_0.05O₂) being cycled at 45^oC was systematically researched. Electrochemical impedance spectrum (EIS) results showed that the SEI resistance (R_SEI) and charge transfer resistance (R_ct) went up to 83.41% and 211.34% before and after the NCM811 material being cycled at 45^oC, …

Investigating Geochemical Processes Of Fluid-Rock Interactions On Materials Related To Energy And Environment, Zelong Zhang

LSU Doctoral Dissertations

Understanding the potential processes of radionuclides released from nuclear waste forms is essential to the safe disposal and containment of nuclear waste. Iodoapatite, a potential waste form for radioiodine, was chosen as a model system to examine the impact by common aqueous anions on iodine release processes. Four semi-dynamic leaching tests were performed using 0.1 mol/L NaCl, Na₂CO₃, Na₃PO₄, and Na₂SO₄ solutions respectively under 90 °C, 1 bar, fixed S/V ratio 5/m (sample surface area to solution volume), and with 24-hour replacement of the leaching solutions. Solution analysis and …

Benzosiloles With Crystallization-Induced Emission Enhancement Of Electrochemiluminescence: Synthesis, Electrochemistry, And Crystallography, Liuqing Yang, Donghyun Koo, Jackie Wu, Jonathan M. Wong, Tyler Day, Ruizhong Zhang, Harshana Kolongoda, Kehan Liu, Jian Wang, Zhifeng Ding, Brian Pagenkopf

Chemistry Publications

Crystallization-induced emission enhancement (CIEE) was demonstrated for the first time for electrochemilunimescence (ECL) with two new benzosiloles. Compared with their solution, the films of the two benzosiloles gave CIEE of 24 times and 16 times. The mechanism of the CIEE-ECL was examined by spooling ECL spectroscopy, X-ray crystal structure analysis, photoluminescence, and DFT calculation. This CIEE-ECL system is a complement to the well-established aggregation-induced emission enhancement (AIEE) systems. Unique intermolecular interactions are noted in the crystalline chromophore. The first heterogeneous ECL system is established for organic compounds with highly hydrophobic properties.

Altering An Epoxy-Amine Thermoset's Performance Through Varying Mix Ratios, Kiersten M. Smith

Master's Theses

Epoxy resins are used in a number of different industries and therefore have application-specific material requirements, from satellites that require materials that operate in space, to paints and coatings that require high scratch resistance and mechanical durability, to medical devices, designed to be in continuous contact with biological fluids. Commercial epoxy products come with manufacturer’s information explaining the epoxy properties and recommended preparation processing conditions, which may include epoxy resin to curing agent mix ratio (Part A : Part B), cure time, and cure temperature, for example. Due to proprietary reasons, it can be difficult to understand why these values …

Pitting Corrosion Of Oerlikon’S Abrasion Resistant Ferritic Stainless Steels, Matthew P. Nalty, Emma Wagstaff

Materials Engineering

Existing hardfacing coatings for hydraulic cylinders and brake disc applications crack during use leaving the components susceptible to corrosion. To address this problem, Oerlikon has designed three new alloys to be abrasion and corrosion resistant. This paper reviews the literature necessary to understand and quantify pitting resistance of stainless-steel alloys. It documents one round of testing ASTM G48 method A: Ferric Chloride Pitting Test of Stainless Steels on the new alloys P72-X9, P72-X13, P129-X9, as well as samples of 431, 316, and 2205 stainless steels. This paper also discusses improvements to the G48 testing method and industry use of the …

The Reduction, Sequestration, And/Or Coordination Of Technetium-99 Utilizing Polyoxometalates And Nanomaterials, Colleen Mb Gallagher

Dissertations, Theses, and Capstone Projects

Research into the sequestration of radionuclides from aqueous media is being conducted due to the contamination of aqueous waste effluents and groundwater with highly toxic long-lived radionuclides. These contaminants are introduced into water and streams from legacy nuclear sites, nuclear reactor operations, nuclear fuel reprocessing, nuclear weapons testing, and plutonium production. A major contributor (~6%) to the waste from thermal neutron fission of uranium-235 is the radionuclide technetium-99 (⁹⁹Tc). It is considered a long-lived radioisotope with a half-life of 2.1x10⁵ years. It is a weak beta emitter with a max energy of 0.29 MeV and is most …

Synthesis And Characterization Of Porous Carbon Composite Derived From Biomass Waste For Supercapacitor Application, Cheng Kim Sim

Student Works (2020-2029)

Energy storage devices have gradually dominated human daily activities and indispensable to economy development such as supercapacitor and battery. There are few factors determining the performance of supercapacitor and active material is one of the crucial. Therefore, biomass such as pineapple peel (PP) and green waste (GW) were preferred and prior mixed with manganese and tin carbonate to synthesize carbon composite (PP/GW-ZMO and PP/GW-ZTO) via combustion. Brunauer–Emmett–Teller (BET) was employed to study the textural properties with the highest specific surface area obtained in PP-C (1765.92 m2g-1) and GW-C (1613.92 m2g-1). The existence of composite materials was examined using x-ray diffraction …

I. Non-Degradable Polysiloxane Networks For Controlled Release Applications, And Ii. Additive Free, Degradable Silyl-Ether Furyl-Maleimide Networks, Caleb M. Bunton

Chemistry Theses and Dissertations

I. Two different series of non–degradable polysiloxane networks were prepared for the encapsulation and controlled release of a small molecule agent. For the first series, hydrosilylation was utilized to prepare networks of varying crosslink densities, as determined from swelling studies, from vinyl terminated and silylhydride functional poly(dimethyl)siloxanes. For the second series, the thiol-ene reaction was utilized to prepare networks of varying crosslink densities, as determined from swelling studies, from vinyl terminated and mercaptopropyl functional poly(dimethyl)siloxanes. Nile red dye was used as an encapsulated agent and dye release from each series of networks was measured using UV–vis spectroscopy to determine controllability …

Effect Of Post-Consumer Content And Bioplastic Incorporation On Polymeric Resin In Consumer Applications, Shelby Bicknell

Electronic Theses & Dissertations

Controversy surrounds the use of plastic products, primarily due to their potentially negative impact on the environment at the end of their lifecycle. The most widely used plastics are manufactured from petrochemicals such as petroleum, coal or natural gas. Petrochemical plastics are not able to readily breakdown in the environment, which aggravates the existing pollution problems. Fortunately, there are eco-friendly alternatives to petrochemical-based plastics. Bioplastics may be derived from renewable sources, biodegradable, or both. Bio-based plastics are plastics that may be derived from renewable biomass sources including, but not limited to, vegetable oils, cornstarch, straw, woodchips, and food waste. They …

Fabrication Of Polymer Monoliths Within The Confines Of Non-Transparent 3d-Printed Polymer Housings, Noor Abdulhussain, Suhas H. Nawada, Sinéad Currivan, Marta Passamonti, Peter J. Schoenmakers

Articles

In the last decade, 3D-printing has emerged as a promising enabling technology in the field of analytical chemistry. Fused-deposition modelling (FDM) is a popular, low-cost and widely accessible technique. In this study, RPLC separations are achieved by in-situ fabrication of porous polymer monoliths, directly within the 3D-printed channels. Thermal polymerization was employed for the fabrication of monolithic columns in optically non-transparent column housings, 3D-printed using two different polypropylene materials. Both acrylate-based and polystyrene-based monoliths were created. Two approaches were used for monolith fabrication, viz. (i) in standard polypropylene (PP) a two-step process was developed, with a radical initiated wall-modification step …

An Atomistic Study Of The Effects On Mechanical Properties And Bonding Interactions Of Carbon Nanofillers In Nylon 6 Nanocomposites, Michael Roth

Dissertations

Polymers have potential for a wide range of applications. The effectiveness of polymers can be further enhanced through the addition of nanofillers that improve thermal, mechanical, and electrical properties of the polymer. Carbon based nanofillers such as carbon nanotube (CNT), graphene, and carbon nanofibre (CNF) are of particular interest due to their high properties and high aspect ratios. However, limited understanding of the governing interactions of these nanofillers with polymers limits the effectiveness of the final nanocomposite.

The first facet of this dissertation focuses on determining the dominating interactions between pristine CNT and graphene with nylon 6 monomer and the …

Enhancing Upconversion Nanoparticle Performance Of Nayf4: Yb,Tm With Doping Optimization And Shell Addition And Of Nayf4: Yb,Er With Yb,Nd Shell Addition, Ashleigh M. Chov

Honors Thesis

Upconversion (UC), is a phenomenon that occurs when low-energy excitation (usually near-infrared (NIR)) results in higher-energy emission. Upconversion nanoparticles (UCNPs) are particles less than 100 nm in size that are synthesized using rare earth metals such as Yb, Er, Tm, and Y. UCNPs have important applications in a variety of fields, including bio-imaging, security printing, and latent fingerprint development. Traditional methods for latent fingerprint development such as fluorescent powder dusting have several drawbacks including low contrast, high background interference, and autofluorescence. NIR-to-NIR UCNPs are composed of NaYF₄: Yb, Tm and emit 800 nm light under 980 nm excitation …

Enhancement Of Phase Change Material Sorbitol By Nanoparticle Inclusion For Improving Thermal Energy Storage Capabilities, Joshua Kasitz

Mechanical Engineering Undergraduate Honors Theses

Thermal management of electronic devices has become an increasingly vital field of study with the rapid miniaturization of many key electrical components. With the significant improvement of semiconductor manufacturing and intensified focus on interconnects, electronic devices have decreased in size at an incredible rate. Decreasing spatial requirements is essential to improving device capabilities as the electronic system is able to incorporate more components. Currently, electronic systems are drastically limited by the capabilities of their cooling mechanisms. Smaller devices lead to large increases in the energy density of the system and require more powerful cooling systems to maintain proper component operating …

Mesoporous Adsorbents For Perfluorinated Compounds, Bertha Lotsi

Electronic Theses and Dissertations

Effective adsorbents for polyfluorinated compounds (PFCs) were successfully prepared. And they were tested in the adsorption of perfluorooctanoic and perfluorooctanesulfonic acids. Bridged silsesquioxanes containing secondary and tertiary amino groups were synthesized by sol-gel condensation of bis[3-(trimethoxysilyl)propyl]amine and bis[3-(methylamino)propyl]-trimethoxysilane in acidic media with surfactants. Obtained materials are mesoporous with a high BET surface area. They combine high structural stability with a high concentration of surface amino groups serving as adsorption sites. Batch adsorption tests demonstrated their extremely high adsorption capacity on PFCs: in some experiments, it reached up to 88% of the adsorbent weight. Adsorption of PFCs changed the surfaces of …

Immobilization Of Phosphotungstic Acid On Silica Surface For Catalytic Alkylation Of Aromatic Compounds, Anastasia Kuvayskaya

Electronic Theses and Dissertations

Superacidic mesoporous materials containing covalently embedded PTA were synthesized by sol-gel method. Tetraethyl orthosilicate (TEOS) and phosphotungstic acid (PTA) were used as precursors in the synthesis, ionic and nonionic surfactants were used as pore-forming agents, the reaction proceeded in acidic media. TEM images revealed mesoporous structure with embedded PTA clusters. FT-IR spectra of obtained materials contained characteristic bands of PTA at 957 cm-1. Synthesized catalysts had high BET surface area and high concentration of acidic sites. Alkylation of 1,3,5-trimethylbenzene by 1-decene demonstrated high catalytic activity. The catalyst obtained with Pluronic P123 as a template was the most effective and resulted …

The Synthesis Of Urethane Acrylate Resin From Palm Fatty Acid Distillate And Some Mechanical Properties, Kim Teck Teo

Student Works (2020-2029)

Depletion of petroleum reserves and increasing environmental concerns have stimulated the efforts to explore materials from readily available, renewable natural resources, such as carbohydrates, oils, fats and proteins. Plant oil and its fatty acids are promising renewable resources to produce environmentally friendly polymeric materials. Palm oil is a major crop in Malaysia and consequently palm fatty acid distillate (PFAD) has been an abundant by-product during the refinery process. PFAD could be a renewable raw material for industrial application. Thus, we develop new PFAD-based acrylate resins UV curable for coatings applications. The resins could be produced by two approaches. Firstly, mixtures …

Surface Chemistry And Surface Properties Of Energetic Nitrocellulose (Nc), Henry Grau

Seton Hall University Dissertations and Theses (ETDs)

This research describes an investigation into the wettability of nitrocellulose (NC), most importantly to nitroglycerin (NG), which are key components of formulations used to propel military ammunition. NG demonstrates complete wetting of NC and, overtime, NG sweats on the NC surface and leaks out. The leaking out of NG from the solid formulation is a known cause of fires and explosions resulting from storage. The origin of this research is inspired by the need to engineer a solution to leakage problems of energetic plasticizer in NC based propellant. While searching for a viable material for a specific application, we journeyed …

Direct Carbon Solid Oxide Fuel Cells, Jiang Liu, Xiao-Min Yan

Journal of Electrochemistry

Carbon is richly reserved in coal, biomasses, and many other nature resources. It is usually used as an energy source through oxygen oxidation reaction. The oxidation is generally realized through combustion which causes serious air pollution. Besides, the conversion efficiency of generating electricity through the combustion process is limited by Carnot efficiency. A direct carbon solid oxide fuel cell (DC-SOFC) is a solid oxide fuel cell (SOFC) directly operated with solid carbon as the fuel. It can convert the chemical energy of carbon into electricity with high efficiency. The concentration of produced CO₂ from a DC-SOFC is so high …

Development Status And Prospects Of Hydrogen Production By High Temperature Solid Oxide Electrolysis, Wen-Qiang Zhang, Bo Yu

Journal of Electrochemistry

Solid oxide electrolysis cell is an advanced energy conversion device with high efficiency, simplicity, flexibility, and environmental friendliness. It is currently a research hotspot in the international energy field. This paper introduces and analyzes the basic principles, key materials, system components and developments of solid oxidation electrolysis cells. Furthermore, the recent research progresses, challenges and future development directions in solid oxidation electrolysis cells in the field of high-efficiency hydrogen production are summarized and outlined.

Materials, Micro-Stacks And Related Applications Of Single-Chamber Solid Oxide Fuel Cells, Zhe Lv, Bo Wei, Zhi-Hong Wang, Yan-Ting Tian

Journal of Electrochemistry

Single-chamber solid oxide fuel cell (SC-SOFC) is a special type of fuel cells, in which both an anode and a cathode are placed in one chamber. Its working principle relies on the selective catalytic activity of the electrodes towards fuel and oxidant in a gas mixture, leading to the generation of an electromotive force. Because of its unique principle and structure, SC-SOFC has many advantages such as sealing-free, easy stacking, quick start-up and no carbon deposition, thus, it possesses large potential in application. Herein, the principles and characteristics of SC-SOFC are introduced. Furthermore, the SC-SOFC materials, micro-stack design, degeneration mechanisms …

Electrochemical Performance Improvement Of Li2Mno3 Cathode Materials By Mgf2 Coating, Du-Dan Wang, Fei Wang, Huan-Huan Zhai, Yu-Peng Li, Na-Chuan Yang, Kang-Hua Chen

Journal of Electrochemistry

Cathode material Li₂MnO₃ has received more and more attention owing to its high theoretical capacity (459 mAh·g ^-1). However, the low initial coulombic efficiency and the poor cycle stability hamper its practical application in lithium-ion batteries. Herein, we investigated the crystal structure and electrochemical performance of Li₂MnO₃ by introducing MgF₂ coating layer. The results indicated that the conversion of partial layer Li₂MnO₃ to spinel phase induced by MgF₂ coating could reduce the initial irreversible capacity and improve the first cycle efficiency. The initial coulombic efficiencies of the 0.5wt.%, …