Horseradish Peroxidase-Attapulgite Clay Nanocomposites: Fabrication And Application To Sensing The Extracellular H2O2 Released From Cells,
2014
Jiangsu Key Laboratory of New Power Batteries, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210046, China;
Horseradish Peroxidase-Attapulgite Clay Nanocomposites: Fabrication And Application To Sensing The Extracellular H2O2 Released From Cells, Ping Wu, Chen-Xin Cai
Journal of Electrochemistry
The nanostructured attapulgite clay was employed as a support matrix for immobilizing horseradish peroxidase (HRP). FTIR and electrochemical methods demonstrated that HRP had been effectively assembled on attapulgite surface with the formation of HRP-attapulgite nanocomposites. The HRP-attapulgite hybrid was deposited on the glassy carbon (GC) electrode forming the HRP-attapulgite/GC electrode. Cyclic voltammetric results showed a pair of well-defined redox peaks, which were ascribed to direct electron transfer (DET) of HRP, with the formal potential E0′ = -335 mV (vs. SCE) in the phosphate buffer solution (PBS, pH 7.0). The dependence of E0′ on solution pH indicated …
Novel Electrochemical Interfaces Based On Functional Nanomaterials And Their Related Applications,
2014
State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022;University of Chinese Academy of Sciences, Beijing 100039;
Novel Electrochemical Interfaces Based On Functional Nanomaterials And Their Related Applications, Cheng-Zhou Zhu, Lei Han, Shao-Jun Dong
Journal of Electrochemistry
Due to the unique optical, electronic, magnetic and catalytic properties, functional nanomaterials provide new opportunities for the rapid development in a variety of disciplines and show considerable promise in different fields. Specifically, constructions of the novel electrochemical interface using various nanomaterials and exploring their advanced electrochemical properties have received great attention to develop electrochemical devices with potential applications. In this account, we focus on our up-to-date progress in the construction of novel electrochemical interfaces based on nanomaterials, mainly highlighting our research advances on electrochemical sensors, fuel cells and fluorescence spectroelectrochemistry. These novel advanced nanomaterials endow them excellent performances and open …
The Ionic Diffusion Model For The Solid Oxide Cathode And Its Verification By The Electrolysis Of Ta2O5 In Molten Cacl2,
2014
College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China;
The Ionic Diffusion Model For The Solid Oxide Cathode And Its Verification By The Electrolysis Of Ta2O5 In Molten Cacl2, Hua-Lin Chen, Zhi-Yong Wang, Xian-Bo Jin, George Z. Chen
Journal of Electrochemistry
The deoxidation speed of a solid oxide cathode in molten CaCl2 can be estimated by the PRS steady diffusion model of O2-, which correlates the deoxidation speed with the precursor porosity, P, the metal-to-oxide molar volume ratio, R, and the cathode volume shrinkage S. The PRS model indicates that the porosity of the oxide cathode has important influence on the deoxidation speed, and provides a very simple equation for the prediction of the optimal cathode porosity. For the electrolysis of Ta2O5, the porosity of the cathode is better to be within 50%. …
23Na Mas Nmr Spectroscopic Study Of Na2Mnpo4F As Cathode Material For Sodium-Ion Battery,
2014
State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian, China;
23Na Mas Nmr Spectroscopic Study Of Na2Mnpo4F As Cathode Material For Sodium-Ion Battery, Xu Hou, Gui-Ming Zhong, Xiao-Chen Lin, Zi-Geng Liu, Xiao-Biao Wu, Yong Yang
Journal of Electrochemistry
The Na2MnPO4F is one of the promising cathode materials for the sodium ion batteries. In the paper, we employed the ex situ X-ray diffraction and solid state NMR techniques to study the charge and discharge processes of this material, including the crystal structure and sodium sites changes. The ex situ x-ray diffraction patterns showed that two new diffraction peaks could be observed at 31o and 36o indicating an intermediate phase formed with the extraction of Na+. From the 23Na MAS NMR spectrum of the material, three peaks were seen at -209 …
Effects Of Oxygen Coverage And Hydrated Proton Model On The Dft Calculation Of Oxygen Reduction Pathways On The Pt(111) Surface,
2014
College of Chemistry and Chemical Engineering, Hunan University of Arts and Science, Changde 415000, Hunan, China;College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China;
Effects Of Oxygen Coverage And Hydrated Proton Model On The Dft Calculation Of Oxygen Reduction Pathways On The Pt(111) Surface, Li-Hui Ou, Sheng-Li Chen
Journal of Electrochemistry
DFT calculation is used to study various possible steps in the oxygen reduction reaction (ORR), including the adsorption and dissociation process of O2 and the serial protonation process of dissociated products to form H2O on the Pt(111) surface. By using slabs of different sizes, and different numbers of pre-adsorbed oxygen atoms, the coverage effects on the pathways are investigated. The calculated results using different hydrated proton models are also compared. It is shown that the initial step of the ORR is the formation of a protonated end-on chemisorbed state of OOH*, which can transform to an unprotonated …
Electrochemistry At Liquid/Liquid Interfaces And Its Recent Progresses,
2014
Institute of Analytical Chemistry, College of Chemistry and Molecular Engineering, Beijing National Laboratory for Molecular Sciences, Peking University, Beijing 100871, China;
Electrochemistry At Liquid/Liquid Interfaces And Its Recent Progresses, Jing Gu, Yong-Hui Qiao, Xin-Yu Zhu, Xiao-Hong Yin, Xin Zhang, Ye Chen, Zhi-Wei Zhu, Yuan-Hua Shao
Journal of Electrochemistry
Electrochemistry and electroanalytical chemistry at a liquid/liquid interface have attracted much attention in the past few decades since they have been closely related to many applications including exploration in mechanisms of extraction processes and chemical sensing, as well as investigations in phase transfer catalysis, drug release and mimicking the function of biological membranes. In this review, recent progresses in this field in the last decade, especially the investigations in microstructure of liquid/liquid interface, charge (ion and electron) transfer reactions and functionalization of liquid/liquid interfaces, are reviewed.
A Novel Label-Free Colorimetric Assay For Dna Concentration In Solution,
2014
Chapman University
A Novel Label-Free Colorimetric Assay For Dna Concentration In Solution, Molla R. Islam, Michael J. Serpe
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
Optical devices were fabricated by sandwiching a “monolithic” poly(N-isopropylacrylamide-co-N-(3-aminopropyl) methacrylamide hydrochloride) (pNIPAm-co-APMAH) microgel layer between two semitransparent Au layers. These devices, referred to as etalons, exhibit characteristic multipeak reflectance spectra, and the position of the peaks in the spectra primarily depends on the distance between the Au surfaces mediated by the microgel layer thickness. Here, we show that the positively charged microgel layer can collapse in the presence of negatively charged single stranded DNA (ssDNA) due to ssDNA induced microgel crosslinking. The collapse results in a change in the etalon's optical properties, which can be used to detect target DNA …
An Investigation Of Poly(N-Isopropylacrylamide) For Applications With Microfluidic Paper-Based Analytical Devices,
2014
California Polytechnic State University, San Luis Obispo
An Investigation Of Poly(N-Isopropylacrylamide) For Applications With Microfluidic Paper-Based Analytical Devices, Haydn Thomas Mitchell
Master's Theses
N,N′-methylenebisacrylamide-crosslinked poly(N-isopropylacrylamide), also known as P(NIPAM), was developed as a fluid delivery system for use with microfluidic paper-based analytical devices (microPADs). MicroPADs are postage-stamp-sized devices made out of paper that can be used as platforms for low-cost, simple-to-use point-of-care diagnostic assays. P(NIPAM) is a thermally responsive polymer that absorbs aqueous solutions at room temperature and will expel the solutions to microPADs when heated. The fluid delivery characteristics of P(NIPAM) were assessed, and P(NIPAM) was able to deliver multiple solutions to microPADs in specific sequences or simultaneously in a laminar-flow configuration. P(NIPAM) was then shown to be suitable …
Improving Hybrid Solar Cells: Overcoming Charge Extraction Issues In Bulk Mixtures Of Polythiophenes And Zinc Oxide Nanostructures,
2014
California Polytechnic State University, San Luis Obispo
Improving Hybrid Solar Cells: Overcoming Charge Extraction Issues In Bulk Mixtures Of Polythiophenes And Zinc Oxide Nanostructures, Grant T. Olson
Master's Theses
Organic photovoltaics (OPVs) have received a great deal of focus in recent years as a possible alternative to expensive silicon based solar technology. Current challenges for organic photovoltaics are centered around improving their lifetimes and increasing their power conversion efficiencies. One approach to improving the lifetime of such devices has been the inclusion of inorganic metal oxide layers, but interaction between the metal oxides and common conjugated polymers is not favorable. Here we present two methods by which the interactions between polythiophenes and nanostructured ZnO can be made to be more favorable. Using the first method, direct side on attachment …
Kinetics Of Solid Phase Crystallization Of A-Ge Thin Films,
2014
Macalester College
Kinetics Of Solid Phase Crystallization Of A-Ge Thin Films, John D. Graham
Macalester Journal of Physics and Astronomy
A method was developed to investigate the solid-phase crystallization (SPC) reaction undergone by germanium thin films. Amorphous films were grown by the radio-frequency (RF) magnetron sputtering and then annealed for a maximum of 6 hours at two temperatures: 446°C and 460°C. Crystallinity was measured by resistivity measurements, as well as crystal peak height and area taken from X-ray diffractometer (XRD) data. Initial data shows qualitative agreement with a nucleation-growth model for the observed kinetic process. However, observed peak narrowing phenomena suggests a comprehensive model of XRD measurements of polycrystalline thin films is needed for a rigorous interpretation of the results.
Poly (N-Isopropylacrylamide) Microgel-Based Optical Devices For Sensing And Biosensing,
2014
Chapman University
Poly (N-Isopropylacrylamide) Microgel-Based Optical Devices For Sensing And Biosensing, Molla R. Islam, Andrews Ahiabu, Xue Li, Michael J. Serpe
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
Responsive polymer-based materials have found numerous applications due to their ease of synthesis and the variety of stimuli that they can be made responsive to. In this review, we highlight the group’s efforts utilizing thermoresponsive poly (N-isopropylacrylamide) (pNIPAm) microgel-based optical devices for various sensing and biosensing applications.
Co2 Reduction Under Periodic Illumination Of Zns,
2014
University of Kentucky
Co2 Reduction Under Periodic Illumination Of Zns, Ruixin Zhou, Marcelo I. Guzman
Chemistry Faculty Publications
The photoreduction of CO2 to formate (HCOO–) in sphalerite (ZnS) aqueous suspensions is systematically studied in the presence of Na2S hole scavenger. A series of cut-on filters at λcut-on ≥ 280, 295, 305, 320, and 400 nm are used to measure the reaction rate of formate production. The dependence of the measured reaction rates on λcut-on indicates that a wavelength of λ = 345 nm is associated with the actual bandgap of the semiconductor nanocrystallites suspended in water. The results from apparent quantum yield measurements during periodic illumination experiments suggest that (1) valence-band …
Enhancing The Photovoltaic Performance Of P3ht/Pdib Silsesquioxane Donor-Acceptor System Using Spray Deposition Fabrication Technique,
2014
Western Kentucky University
Enhancing The Photovoltaic Performance Of P3ht/Pdib Silsesquioxane Donor-Acceptor System Using Spray Deposition Fabrication Technique, Venkata Ramana Manda
Masters Theses & Specialist Projects
In the past few years, the solution-processed organic based solar cells gained more importance by meeting the demands for cost effective photovoltaic devices. To date, the focus of the organic photovoltaic devices has been on the optimization of the processing the materials to improve photo conversion efficiency and also by modifying the active components of the organic materials. Recently, it has been recognized that the deposition techniques also plays a major role in enhancing the power conversion efficiencies. Currently, though the most common deposition technique for organic solar cells is spin coating, which does not allow scaling up of the …
Investigation Of The Addition Of Basalt Fibres Into Cement,
2014
Western Kentucky University
Investigation Of The Addition Of Basalt Fibres Into Cement, Jahi Palme
Masters Theses & Specialist Projects
Mechanical properties of concrete are most commonly determined using destructive tests including: compression, flexure, and fracture notch specimen tests. However, nondestructive tests exist for evaluating the properties of concrete such as ultrasonic pulse velocity and impact echo tests. One of major issues with concrete (which has cement as its prime ingredient) is that unlike steel it is quasi-brittle material. It tends to want to crack when tensile stresses develop. Fibres have been added to concrete for many years to reduce the amount of and size of cracks cause by temperature changes or shrinkage. In more recent years, significant research has …
Porphyrin Cross-Linkers For Generating Soluble Molecularly Imprinted Polymers From Polyethyleneimine,
2014
Seton Hall University
Porphyrin Cross-Linkers For Generating Soluble Molecularly Imprinted Polymers From Polyethyleneimine, Mohammed R. Elshaer
Seton Hall University Dissertations and Theses (ETDs)
Molecular recognition is vital to many biochemical processes and is at the heart of promising bio-medically related technologies. Molecular imprinting has a long-standing history as a successful method for mimicking the molecular recognition phenomena exhibited by nature, whereby artificial receptors are prepared for a given target molecule based on synthetic polymers. The molecularly imprinted polymer (MIP) contains a three dimensional network with a memorized cavity specific to the shape and functionality of the templated target molecule. The utility of traditional MIPs has been limited due to an inherent lack of solubility. We have worked toward developing a system that allows …
The Impact Of Surface Ligands And Synthesis Method On The Toxicity Of Glutathione-Coated Gold Nanoparticles,
2014
Oregon State University
The Impact Of Surface Ligands And Synthesis Method On The Toxicity Of Glutathione-Coated Gold Nanoparticles, Bryan Harper, Federico Sinche, Meenambika Gowrishankar, Grant Marquart, Marilyn R. Mackiewicz, Stacey L. Harper
Chemistry Faculty Publications and Presentations
Gold nanoparticles (AuNPs) are increasingly used in biomedical applications, hence understanding the processes that affect their biocompatibility and stability are of significant interest. In this study, we assessed the stability of peptide-capped AuNPs and used the embryonic zebrafish (Danio rerio) as a vertebrate system to investigate the impact of synthesis method and purity on their biocompatibility. Using glutathione (GSH) as a stabilizer, Au-GSH nanoparticles with identical core sizes were terminally modified with Tryptophan (Trp), Histidine (His) or Methionine (Met) amino acids and purified by either dialysis or ultracentrifugation. Au-GSH-(Trp)2 purified by dialysis elicited significant morbidity and mortality at …
A Facile Route To Tailoring Peptide-Stabilized Gold Nanoparticles Using Glutathione As A Synthon,
2014
Portland State University
A Facile Route To Tailoring Peptide-Stabilized Gold Nanoparticles Using Glutathione As A Synthon, Rosina Ho Wu, Tan P. Nguyen, Grant W. Marquart, Thomas J. Miesen, Theresa Mau, Marilyn R. Mackiewicz
Chemistry Faculty Publications and Presentations
The preparation of gold nanoparticles (AuNPs) of high purity and stability remains a major challenge for biological applications. This paper reports a simple synthetic strategy to prepare water-soluble peptide-stabilized AuNPs. Reduced glutathione, a natural tripeptide, was used as a synthon for the growth of two peptide chains directly on the AuNP surface. Both nonpolar (tryptophan and methionine) and polar basic (histidine and dansylated arginine) amino acids were conjugated to the GSH-capped AuNPs. Ultracentrifugation concentrators with polyethersulfone (PES) membranes were used to purify precursor materials in each stage of the multi-step synthesis to minimize side reactions. Thin layer chromatography, transmission electron …
Selection Of The Process Parameters For The Mass Plating Of Discrete Electronic Components,
2014
Technological University Dublin
Selection Of The Process Parameters For The Mass Plating Of Discrete Electronic Components, Ann Hopper
Articles
The miniaturisation of electronic components coupled with requirements for high temperature lead free soldering has forced the improvement of the termination finish of surface mount components to meet the critical demands of the electronic industry. In the present work the processing parameters necessary to plate miniature multilayer varistors (MLV’s) have been explored. The tooling selected was a “Rotary flow-thru’ plater” which achieved high volume plating with
Preparation And Electrochemical Performances Of Cofe2O4/Gns Nanocomposites As Anode Material For Lithium Ion Battery,
2014
State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen 361005, Fujian, China;
Preparation And Electrochemical Performances Of Cofe2O4/Gns Nanocomposites As Anode Material For Lithium Ion Battery, Mo-Chao Cai, Sen-Rong Cai, Ming-Sen Zheng, Quan-Feng Dong
Journal of Electrochemistry
The CoFe2O4/GNS was synthesized by a simple one-pot solvothermal method. The results obtained by X-ray diffraction (XRD) and transmission electron microscopy (TEM) showed that the CoFe2O4 particles with sizes of 15 nm dispersed on the surface of graphene uniformly. Electrochemical tests indicated that the CoFe2O4/GNS nanocomposite exhibited excellent cyclic stability with almost 95.8% capacity retention after 100 cycles at the current density of 500 mA·g-1 and delivered a high reversible capacity of 482 mAh·g-1 at the current density of 2 A·g-1.
Effect Of Temperature On The Self-Humidifying Open-Cathode Proton Exchange Membrane Fuel Cell,
2014
School of Electrical Engineering, Southwest Jiaotong University, Chengdu 610031, China;School of Mechanical Engineering, Southwest Jiaotong University, Chengdu 610031, China;
Effect Of Temperature On The Self-Humidifying Open-Cathode Proton Exchange Membrane Fuel Cell, Si-Chen Zhao, Ben Wang, Qiu-Hong Jia, Ming Han, Yu-Hong Xie
Journal of Electrochemistry
Based on the experiments about the output characteristics of a home-made temperature-controlled PEMFC system with atmospheric pressure and no external humidifying condition in different loading voltages and operating temperatures, the optimum operating temperature at different loading voltages can be obtained by tracking the output characteristics of PEMFC operating over a range of temperatures. By analyzing the fitted data the kinetic parameters are evaluated and the effect of different operating temperatures on the PEMFC performance is discussed from a view of electrode kinetics.
