Investigations Into Effects Of Modified Prolines On Cis-Trans Isomers And Polypeptide Secondary Structure & Prediction Of Spectroscopic Properties Of Phthalonitriles For Characterization,
2021
Seton Hall University
Investigations Into Effects Of Modified Prolines On Cis-Trans Isomers And Polypeptide Secondary Structure & Prediction Of Spectroscopic Properties Of Phthalonitriles For Characterization, Jeffrey Raab
Seton Hall University Dissertations and Theses (ETDs)
Proline is a unique amino acid because it is the only amino acid whose side chain wraps around and bonds back to the peptide backbone. This ring shape helps proteins form conformations which would otherwise not be possible such as hairpin turns. The cis/trans isomerization of the peptide bond between the preceding amino acid (Xaa) and Proline is important in determining how the secondary structure folds. Thus, being able to control the cis/trans isomerization is important when a specific conformation is desired; Proline can be modified to get make the equilibrium shift whichever way is needed. The modifications …
Computational Investigation Of Stellar Cooling, Noble Gas Nucleation, And Organic Molecular Spectra,
2021
University of Mississippi
Computational Investigation Of Stellar Cooling, Noble Gas Nucleation, And Organic Molecular Spectra, Jax Dallas
Honors Theses
Since the advent and optimization of the Hartree-Fock method, quantum chemistry has been utilized to investigate systems operating on timeframes and environments traditionally unavailable to bench-top chemistry. As computational methods have grown more robust and less time consuming, quantum chemistry has been utilized to investigate a range of fields, including the steadily growing discipline of computational astrochemistry. Through the lens of computational astrochemistry, chemistry that occurred billions of years ago can be explored with equal clarity to that which is currently happening in the cosmos. The work presented throughout this thesis is a series of investigations into different timeframes of …
Understanding Shear Thinning Using Brownian Dynamics Simulation,
2021
University of Tennessee at Chattanooga
Understanding Shear Thinning Using Brownian Dynamics Simulation, Mackenzie Nicole Wall
Honors Theses
In this work, we study the changes in structure during the shear thinning regime using Brownian Dynamics with a simple steady-state shear flow of binary charged colloidal suspension. Previous research has analyzed the viscosity, radial distribution, elasticity and plasticity of materials with rheo-SANS experimentation; however, less research has been conducted to replicate the experiment through computer simulations. With Brownian Dynamic Simulation, this study was able to reproduce the results obtained in a recent rheo-SANS experiment and it also explored the viscosity, radial distribution, elastic and plastic behavior of a system under different parameters. The comparison of simulated data with experimental …
The Effect Of The Apolipoprotein A1 (Apoa1): The Stability And Folding In Potassium Chloride Environment,
2021
University of Tennessee at Chattanooga
The Effect Of The Apolipoprotein A1 (Apoa1): The Stability And Folding In Potassium Chloride Environment, Alexandra Paladian
Honors Theses
Healthy levels of potassium chloride (KCl) can significantly affect the workings of the cholesterol level of the human body and how they pertain to an individual person. The search for a better salt additive for the human diet can provide a better option for people who experience high cholesterol levels and heart disease. The study focuses on the experimental design of the Molecular Dynamic (MD) simulation of the Apolipoprotein A1 (APOA1) in the potassium ion solution environment to determine the stability and folding of the protein. The study also compares its data to the previous experimental design of chloride ions …
Molecular Dynamic Simulation Of The Complex Folding Patterns Of Apolipoprotein A1 In Various Concentrations Of Potassium Chloride,
2021
University of Tennessee at Chattanooga
Molecular Dynamic Simulation Of The Complex Folding Patterns Of Apolipoprotein A1 In Various Concentrations Of Potassium Chloride, Hannah Holmberg
Honors Theses
Apopliprotein or ApoA-1 is a complex lipoprotein that functions in the removal of cholesterol from the blood, removing cholesterol from the area around white blood cells and promoting the excretion of lipids through the lymphatic system. Previous research has found that ApoA-1 shows both folded and unfolded conformations depending on the concentration of NaCl in solution in the water around it. The protein was studied using molecular dynamics simulations. Once this state of equilibrium was reached, various structural properties of the protein were measured including the radius of gyration and the radial distribution function. The goal of the project was …
Spectroscopic Analysis Of Potential Astromolecules Via Quantum Chemical Quartic Force Fields,
2021
University of Mississippi
Spectroscopic Analysis Of Potential Astromolecules Via Quantum Chemical Quartic Force Fields, Mason Gardner
Honors Theses
Astrochemistry has been substantially aided by computational techniques, particularly through the use of Quartic Force Field (QFF) analysis. Several methods have proven useful at correlating computed spectroscopic data with experimental observations. The F12-TZ QFF correlated well with experimental data for silicon oxide compounds, particularly those potentially involved in development from rocky bodies to planetary masses [27]. Compared to argon matrix experimental data, the vibrational frequencies for the molecules SiO2, SiO3, Si2O3, and Si2O4 become less accurate as the complexity of the molecules increases but should still be predictive of infrared characteristics of silicon oxides as they form clusters in space …
Visualization And Quantification Of The Laser-Induced Art Of Tio2 By Photoexcitation Of Adsorbed Dyes,
2021
University of Massachusetts Boston
Visualization And Quantification Of The Laser-Induced Art Of Tio2 By Photoexcitation Of Adsorbed Dyes, Daniela (Labadini) Graf Stillfried Barreto
Graduate Masters Theses
Dye-pretreated anatase TiO2 films, commonly used as photoanodes in dye sensitized solar cells (DSSC), were utilized as a model system to investigate the laser-induced anatase to rutile phase transformation (ART), using N719 dye, N749 dye, D149 dye, and MC540 dye as photo-sensitizers. The visible lasers (532 and 785 nm) used for Raman spectroscopy were able to transform pure anatase into rutile at the laser spot when excitation of the dye sensitizer caused an electron injection from the excited state of the dye molecule into the conduction band of the TiO2. The three dyes with carboxylic acid anchor groups (N719, N749 …
Remote Performance Modulation Of Ultrafiltration Membranes By Magnetically And Thermally Responsive Polymer Chains,
2021
Bhabha Atomic Research Centre
Remote Performance Modulation Of Ultrafiltration Membranes By Magnetically And Thermally Responsive Polymer Chains, Arijit Sengupta, Anh Vu, Xianghong Qian, Sumith R. Wickramasinghe
Chemical Engineering Faculty Publications and Presentations
Ultrafiltration membranes, that respond to an external magnetic field and local temperature have been developed. Surface-initiated activator-generated electron transfer (AGET) atom transfer radical polymerization (ATRP) has been used to graft poly(N-isopropylacrylamide) (PNIPAm) from the surface of 300 kDa regenerated cellulose membranes. The polymerization initiator was selectively attached to the entire membrane surface, only the outer membrane surface or only the inner pore surface. A superparamagnetic nanoparticle was attached to the end of the polymer chain. The DI water flux as well as the flux and rejection of bovine serum albumin were investigated in the absence and presence of a 20 …
Application Of Atomically Precise Metal Nanoclusters In Electrocatalysis,
2021
1. State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry,Chinese Academy of Sciences, Changchun 130022, Jilin, China;2. University of Science and Technology of China, Hefei 230026, Anhui, China;
Application Of Atomically Precise Metal Nanoclusters In Electrocatalysis, Zhi-Hua Zhuang, Wei Chen
Journal of Electrochemistry
Metal nanoclusters (M NCs) consist of only several to a few hundred of metal atoms and possess core sizes less than 2 nm. Owing to the quantum size effect, the electronic states of M NCs evolve to discrete levels similar to the molecule energy gaps, other than a continuous density of states to produce plasmon characteristic of bulk metal nanoparticles (M NPs). In comparison with the conventional M NPs, M NCs exhibit dramatically unique electronic and optical properties, such as molecule-like energy gaps, strong photoluminescence and high catalytic properties, which make them promising for potential application in numerous fields, such …
Preface To The Special Issue Of The Journal Of Electrochemistry Celebrating 100 Years Of Chemistry At Xiamen University,
2021
State Key Laboratory for Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen 361005, Fujian, China
Preface To The Special Issue Of The Journal Of Electrochemistry Celebrating 100 Years Of Chemistry At Xiamen University, Chang-Jian Lin, Shi-Gang Sun
Journal of Electrochemistry
No abstract provided.
Luminol/Sulfamic Acid Electrochemiluminescence And Its Application For Dopamine Detection,
2021
1. State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun 130022, Jilin,China; 2. School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei 230026, Anhui, China; 3. Wolkite University, College of Natural & Computational Science, Department of Chemistry, P.O Box 07, Wolkite, Ethiopia
Luminol/Sulfamic Acid Electrochemiluminescence And Its Application For Dopamine Detection, Tesfaye Hailemariam Barkae, Mohamed Ibrahim Halawa, Tadesse Haile Fereja, Shimeles Addisu Kitte, Xian-Gui Ma, Ye-Quan Chen, Guo-Bao Xu
Journal of Electrochemistry
Herein, sulfamic acid (SA) was utilized, for the first time, to enhance significantly the luminol electrochemiluminescence (ECL). With the SA concentration increased from 0.1 μmol·L-1 to 500 μmol·L-1 the ECL intensity increased proportionally. The developed luminol/SA ECL system was employed to detect dopamine (DA) based on its prominent quenching effect. The Stern-Volmer equation of Io/I= 1+Ksv[DA] could be applied to express well the quenching mechanism of DA in the luminol/SA ECL system. The calibration plot showed that the increase in the DA concentration from 0.5 to 20 μmol·L-1 decreased linearly the ECL intensity …
Electrochemiluminescence Imaging Hydrogen Evolution Reaction On Single Platinum Nanoparticles Using A Bipolar Nanoelectrode Array,
2021
State Key Lab of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering,Nanjing University, Nanjing 210023, Jiangsu China;
Electrochemiluminescence Imaging Hydrogen Evolution Reaction On Single Platinum Nanoparticles Using A Bipolar Nanoelectrode Array, Xiang Qin, Zhong-Qiu Li, Jian-Bin Pan, Jian Li, Kang Wang, Xing-Hua Xia
Journal of Electrochemistry
A high-density (5.7 × 108 cm-2) nanoelectrode array with the electrode diameter of 200 nm and the interelectrode distance of 450 nm were fabricated. The nanoelectrode array consisted of gold nanowires embedded in a porous anodic aluminum oxide (AAO) matrix, having regular nanoelectrode distribution and highly uniform nanoelectrode size. The gold nanoelectrode array was used as a closed bipolar nanoelectrode array combined with electrochemiluminescence (ECL) method to map the electrocatalytic activity of platinum nanoparticles toward hydrogen evolution reaction (HER) by modifying the catalysts on single nanoelectrodes. Results show that HER on single bipolar nanoelectrodes could be imaged …
Oxygen-Exposure Induced Rapid Oxidation Of Spiro-Ometad In Cspbibr2 Perovskite Solar Cells,
2021
Research Institute for Biomimetics and Soft Matter, Fujian Provincial Key Laboratory for Soft Functional Materials Research, Department of Physics, College of Physical Science and Technology,Xiamen University, Xiamen 361005, Fujian, China;
Oxygen-Exposure Induced Rapid Oxidation Of Spiro-Ometad In Cspbibr2 Perovskite Solar Cells, Wei-Guo Wang, Tian Bai, Gao-Fei Xue, Mei-Dan Ye
Journal of Electrochemistry
2,2′,7,7′-tetrakis(N,N-di-p-methoxyphenyl-amine)-9,9′-spirobifluorene (Spiro-OMeTAD) is the most widely used hole transport material in perovskite solar cells (PSCs). However, its oxidation in the air takes a long time and results in the attack of perovskite by water. In this regard, we performed the oxidation process of Spiro-OMeTAD in oxygen, where perovskite can be protected from water, guaranteeing the integrity of perovskite. It was demonstrated that the champion Spiro-OMeTAD based CsPbIBr2 PSCs after oxygen oxidation achieved a 7.19% power conversion efficiency (PCE), showing a higher PCE than 6.29% of the champion device oxidized in air. A series of electrochemical characterization methods were applied …
Theoretical Studies Of Metal-N-C For Oxygen Reduction And Hydrogen Evolution Reactions In Acid And Alkaline Solutions,
2021
1. Department of Chemical and Biological Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong 999077, China;
Theoretical Studies Of Metal-N-C For Oxygen Reduction And Hydrogen Evolution Reactions In Acid And Alkaline Solutions, Xue-Ping Qin, Shang-Qian Zhu, Lu-Lu Zhang, Shu-Hui Sun, Min-Hua Shao
Journal of Electrochemistry
Single atom catalysts (SAC) have been regarded as the promising alternatives to platinum group metals due to their low costs and potentially high catalytic activities in various electrocatalytic reactions. The atomic mechanism understanding of activity discrepancy among different metal and nitrogen co-doped carbon-based catalysts is still lacking. Here, non-precious metal and nitrogen co-doped carbons (Me-N-C, Me = Fe and Co) as the model catalysts are investigated by combining experimental and theoretical studies to explore the catalytic activities and corresponding reaction mechanisms toward oxygen reduction reaction (ORR) and hydrogen evolution reaction (HER) at universal pHs. Atomic theoretical simulations suggest that Fe-N-C …
Electrochemical Gating Single-Molecule Circuits With Parallel Paths,
2021
1. Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, Zhejiang Normal University, Jinhua 321004, Zhejiang, China;
Electrochemical Gating Single-Molecule Circuits With Parallel Paths, Jun-Qing Su, Yi-Fan Zhou, Ling Tong, Ya-Hao Wang, Ju-Fang Zheng, Jing-Zhe Chen, Xiao-Shun Zhou
Journal of Electrochemistry
Electrochemical gating has emerged as a feasible and powerful method to tune single-molecule conductance. Herein, we demonstrate that the electron transport through single-molecule circuits with two benzene rings in parallel could be efficiently gated by electrochemistry. The molecular junctions with two parallel paths are fabricated with Au electrodes by STM break junction (STM-BJ) technique. Their conductance value exhibits a 2.82-fold enhancement by the constructive quantum interference compared to single-molecule junctions with single path for electron tunneling. Furthermore, the conductance of para-benzene based molecule could be electrochemically tuned with a modulation ratio of about 333%·V-1. With the help of …
Lithium Storage Performance Of Hard Carbons Anode Materials Prepared By Different Precursors,
2021
Department of New Energy Materials and Devices, School of Materials and Energy, Guangdong University of Technology, Guangzhou 510000, Guangdong, China;
Lithium Storage Performance Of Hard Carbons Anode Materials Prepared By Different Precursors, Zhen-Lang Liang, Yao Yang, Hao Li, Li-Ying Liu, Zhi-Cong Shi
Journal of Electrochemistry
Hard carbon is one of the most promising anode material for lithium ion batteries (LIBs) owing to its high stability, widespread availability, low-cost, and excellent performance. The electrochemical properties of hard carbon materials depend strongly on the type of precursors. It is, therefore, very important to choose an excellent hard carbon precursor. Polyacrylonitrile, petroleum pitch and peanut shells were used as raw materials to prepare different hard carbon anode materials for LIBs. These hard carbon anode materials were successfully synthesized in two steps. The selected precursor was firstly carbonized at 600℃ for 1 h in argon atmosphere using heating rate …
Pd-Based Electrocatalysts For Oxygen Reduction And Ethanol Oxidation Reactions: Some Recent Insights Into Structures And Mechanisms,
2021
1. Green Catalysis Center, College of Chemistry, Zhengzhou University, Zhengzhou 450001, Henan, P. R. China;2. Department of Chemistry, State University of New York at Binghamton,Binghamton, New York 13902, USA;3. School of Chemical and Biomedical Engineering,Nanyang Technological University, 637459, Singapore;
Pd-Based Electrocatalysts For Oxygen Reduction And Ethanol Oxidation Reactions: Some Recent Insights Into Structures And Mechanisms, Zhi-Peng Wu, Chuan-Jian Zhong
Journal of Electrochemistry
The development of efficient electrocatalysts for applications in fuel cells, including proton-exchange membrane fuel cell (PEMFC) and direct ethanol fuel cell (DEFC), has attracted extensive research attention in recent years. Oxygen reduction reaction and ethanol oxidation reaction are two of the key reactions where the design of active, stable and low-cost electrocatalysts is critical for the mass commercializations of PEMFCs and DEFCs. This challenge stems largely from the limited understanding of the catalyst structures and reaction mechanisms. Progress has been made in investigations of electrocatalysts derived from Pd-based alloy nanomaterials both experimentally and computationally. We highlight herein some of the …
Preparation And Characterization Of "Water-In-Salt" Polymer Electrolyte For Lithium-Ion Batteries,
2021
1. Helmholtz-Institute Muenster (HI MS), IEK-12,Muenster 48149, Germany;
Preparation And Characterization Of "Water-In-Salt" Polymer Electrolyte For Lithium-Ion Batteries, Xu Hou, Xin He, Jie Li
Journal of Electrochemistry
Since the development of wearable and flexible electronic products, the demand of flexible energy storage devices such as batteries and super capacitors is in urgent. To enhance the safety and cycling stability for flexible lithium-ion batteries, “water-in-salt” polymer electrolyte was prepared by introducing 21 mol·kg-1 LiTFSI electrolyte into cross-linked polyacrylamide (PAM) after freeze-drying. A great amount of holes with the size range of 10 ~ 20 μm can be found on the surface and in the bulk of polyacrylamide, which is benefited from the freeze-drying process and acts as a great support for the electrolyte uptake. The “water-in-salt” polymer …
Electrochemical Surface-Enhanced Raman Spectroscopic Studies On Nickel Ultramicroelectrode,
2021
1. School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China;
Electrochemical Surface-Enhanced Raman Spectroscopic Studies On Nickel Ultramicroelectrode, Li-Wen Wu, Wei Wang, Yi-Fan Huang
Journal of Electrochemistry
Nickel (Ni) electrodes are widely used in electrochemical researches. Understanding electrochemical processes on Ni electrodes through in-situ characterization of adsorbed species on their surfaces is helpful for rational optimization and application of Ni electrochemistry. Microelectrochemical surface-enhanced Raman spectroscopy (μEC-SERS) combines the mass transfer feature of ultramicroelectrode with high-sensitivity characterizations of molecular structures, which is a powerful method for studying Ni electrochemistry on polarization and non-equilibrium conditions. The key point of performing μEC-SERS is to make a SERS-active Ni ultramicroelectrode.
Here, we demonstrate a method of preparing a SERS-active Ni ultramicroelectrode through electrochemical deposition of several atomic layers of …
062— Nano-Size Dependence In Aggregation Process Of Beta 2 Microglobulin Coated Gold Colloids,
2021
SUNY Geneseo
062— Nano-Size Dependence In Aggregation Process Of Beta 2 Microglobulin Coated Gold Colloids, Kaylee A. Hausrath
GREAT Day Posters
The formation of the aggregates of the beta 2 microglobulin (b2m) coated nano-gold colloids were investigated for various nanogold colloid sizes ranging between 10 nm and 100 nm. The aggregation process was considered to be initiated by the selfassembly of b2m by transforming the folded to the unfolded structure under highly acidic condition (pH < 4). The formation of the aggregates were monitored by a peak shift of surface plasmon resonance (SPR) band as a function of number of free b2m available. As for relatively smaller size of gold colloid diameter a gradual aggregation process was observed. The size of the aggregates was considered to increase monotonically as the b2m was added. On the other hand, as for relatively larger diameter of gold colloid, stepwise aggregation process was observed. So that the aggregates of a particular size was formed at a certain threshold of the concentration of available free b2m. The majority of the gold surface of the smaller gold size was easily covered and support the aggregation even at the lower concentration of b2m.
