Photophysics Of Substituted [1,4]Benzodioxino[3,2-B]Oxanthrene (Bdo) Chromophores And Their Macromolecules: A Spectroscopy And Density Functional Theory Study.,
2021
University of Louisville
Photophysics Of Substituted [1,4]Benzodioxino[3,2-B]Oxanthrene (Bdo) Chromophores And Their Macromolecules: A Spectroscopy And Density Functional Theory Study., Abdelqader M. Jamhawi
Electronic Theses and Dissertations
Chromophores and macromolecules containing [1,4]benzodioxino[3,2-b]oxanthrene (BDO) has attracted attention since the beginning of this century. Previous studies demonstrated their potential in wide range of applications including gas permeability, hydrogen and energy storage, sensing, and catalysis. Better understanding of the geometrical and electronic structure characteristics of BOD-based chromophores is vital to advance their employment in these applications. This work utilizes spectroscopy techniques coupled with density functional theory methods to provide this required understanding. Substituted BDOs exhibit red-shift of >1 eV in their electronic transitions compared to unsubstituted BDOs. This shift is explained by a molecular orbital reorganization induced by the substituents. …
Computational Investigation Of Nanoparticle Immersion And Selfassembly,
2021
University of Texas at El Paso
Computational Investigation Of Nanoparticle Immersion And Selfassembly, Tara Allison Tyler Nitka
Open Access Theses & Dissertations
Both neutral and charged nanoparticles with a variety of compositions, shapes, and sizes have beenpreviously prepared. These nanoparticles have been demonstrated to self-assemble into a variety of superlattices and binary superlattices both in bulk solution and at surfaces of solutions, and the structures formed by self-assembly have been shown to depend on nanoparticle chemistry and charge as well as on whether assembly takes place at a surface or in bulk. Furthermore, the prepared isolated and self-assembled nanoparticles have a number of biomedical, nanotechnology, and industrial applications. In this Dissertation, I present my research on three general topics. First, I will …
Quantum Chemical Investigation Of Novel Noncovalent Interactions Utilizing Vibrational Spectroscopy,
2021
Southern Methodist University
Quantum Chemical Investigation Of Novel Noncovalent Interactions Utilizing Vibrational Spectroscopy, Seth Francis Yannacone
Chemistry Theses and Dissertations
Theoretical/computational methods have been utilized to investigate a diverse array of questions currently at the forefront of modern chemistry research. The focus of this work is Local Vibrational Mode (LVM) Theory, originally formulated by Konkoli and Cremer, and under continuous development by the CaTcO research group. Derived from LVM theory, local stretching force constants (ka) represent physically meaningful measurements of chem- ical bond strength. Decomposition of normal vibrational modes into LVM contributions, also called characterization of normal modes (CNM), is another powerful manifestation of LVM theory; most notably when applied to the analysis of theoretical/experimental IR/Ra- man spectra. Recent developments …
Pt-Containing Conjugated Polymers And Small Molecules For Bhj Photovoltaic Devices,
2021
University of New Mexico
Pt-Containing Conjugated Polymers And Small Molecules For Bhj Photovoltaic Devices, Yunjeong Kwon
Chemistry and Chemical Biology ETDs
The current state of organic photovoltaic (OPV) devices involve series of small molecular or polymeric systems that can absorb light from the solar spectrum in concert with another material that acts as an acceptor material. Together these materials serve to generate and split bound excitation species then transport the separate charges to their respected electrode. Several limitations have restricted the widescale use of these materials. Since these devices have their genesis in organic materials the OPV devices inherit short exitonic lifetimes, narrow absorption window and a lack of precise control over the morphology. To overcome these limitations, additional molecular engineering …
Bridging The 12-6-4 Model And The Fluctuating Charge Model,
2021
Loyola University Chicago
Bridging The 12-6-4 Model And The Fluctuating Charge Model, Pengfei Li
Chemistry: Faculty Publications and Other Works
Metal ions play important roles in various biological systems. Molecular dynamics (MD) using classical force field has become a popular research tool to study biological systems at the atomic level. However, meaningful MD simulations require reliable models and parameters. Previously we showed that the 12-6 Lennard-Jones nonbonded model for ions could not reproduce the experimental hydration free energy (HFE) and ion-oxygen distance (IOD) values simultaneously when ion has a charge of +2 or higher. We discussed that this deficiency arises from the overlook of the ion-induced dipole interaction in the 12-6 model, and this term is proportional to 1/r …
Petrology And Geochemistry Of Evolved Achondrites: Planetesimal Mantles And Crusts,
2021
University of New Mexico
Petrology And Geochemistry Of Evolved Achondrites: Planetesimal Mantles And Crusts, Zoltan Vaci
Earth and Planetary Sciences ETDs
Melting and differentiation are fundamental to early solar system evolution on planetary bodies that accreted enough material to heat up radioactively or through impacts and breach their solidi. Partially and fully melted material is present in the meteorite record in the form of primitive achondrites and achondrites, which are fragments of planetesimals that underwent heating events in the first few million years of solar system history. Although the vast majority of this material is mafic or ultramafic, new evolved samples, recovered in the last few decades, are pushing the petrologic and geochemical boundaries of planetesimal melting, differentiation, and crust formation. …
Awegnn: Auto-Parametrized Weighted Element-Specific Graph Neural Networks For Molecules.,
2021
University of Kentucky
Awegnn: Auto-Parametrized Weighted Element-Specific Graph Neural Networks For Molecules., Timothy Szocinski, Duc Duy Nguyen, Guo-Wei Wei
Mathematics Faculty Publications
While automated feature extraction has had tremendous success in many deep learning algorithms for image analysis and natural language processing, it does not work well for data involving complex internal structures, such as molecules. Data representations via advanced mathematics, including algebraic topology, differential geometry, and graph theory, have demonstrated superiority in a variety of biomolecular applications, however, their performance is often dependent on manual parametrization. This work introduces the auto-parametrized weighted element-specific graph neural network, dubbed AweGNN, to overcome the obstacle of this tedious parametrization process while also being a suitable technique for automated feature extraction on these internally complex …
Mechanisms Of Spontaneous Curvature Inversion In Compressed Graphene Ripples For Energy Harvesting Applications Via Molecular Dynamics Simulations,
2021
University of Arkansas, Fayetteville
Mechanisms Of Spontaneous Curvature Inversion In Compressed Graphene Ripples For Energy Harvesting Applications Via Molecular Dynamics Simulations, James M. Mangum, Ferdinand Harerimana, Millicent N. Gikunda, Paul M. Thibado
Physics Faculty Publications and Presentations
Electrically conductive, highly flexible graphene membranes hold great promise for harvesting energy from ambient vibrations. For this study, we built numerous three-dimensional graphene ripples, with each featuring a different amount of compression, and performed molecular dynamics simulations at elevated temperatures. These ripples have a convex cosine shape, then spontaneously invert their curvature to concave. The average time between inversion events increases with compression. We use this to determine how the energy barrier height depends on strain. A typical convex-to-concave curvature inversion process begins when the ripple’s maximum shifts sideways from the normal central position toward the fixed outer edge. The …
Ultrafast Adsorbate Excitation Probed With Subpicosecond-Resolution X-Ray Absorption Spectroscopy,
2021
SLAC National Accelerator Laboratory
Ultrafast Adsorbate Excitation Probed With Subpicosecond-Resolution X-Ray Absorption Spectroscopy, Elias Diesen, Hsin-Yi Wang, Simon Schreck, Matthew Weston, Hirohito Ogasawara, Jerry Larue, Fivos Perakis, Martina Dell'angela, Flavio Capotondi, Luca Giannessi, Martin Beye, Filippo Cavalca, Boyang Liu, Jörgen Gladh, Sergey Koroidov, Piter S. Miedema, Roberto Costantini, Tony F. Heinz, Frank Abild-Pedersen, Johannes Voss, Alan C. Luntz, Anders Nilsson
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
We use a pump-probe scheme to measure the time evolution of the C K-edge x-ray absorption spectrum from CO/Ru(0001) after excitation by an ultrashort high-intensity optical laser pulse. Because of the short duration of the x-ray probe pulse and precise control of the pulse delay, the excitation-induced dynamics during the first picosecond after the pump can be resolved with unprecedented time resolution. By comparing with density functional theory spectrum calculations, we find high excitation of the internal stretch and frustrated rotation modes occurring within 200 fs of laser excitation, as well as thermalization of the system in the picosecond …
Preparation Of Co1-XS-Mns@Cnts/Cnfs For Electrocatalytic Oxygen Reduction Reaction,
2021
State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-Sen University, Guangzhou 510275, Guangdong,China;
Preparation Of Co1-XS-Mns@Cnts/Cnfs For Electrocatalytic Oxygen Reduction Reaction, Fang-Yan Liu, Qian Zhang, Yue-Kun Li, Feng Huang, Meng-Ye Wang
Journal of Electrochemistry
As an important cathode reaction in fuel cells and metal-air batteries, oxygen reduction reaction (ORR) is a complex reaction of slow kinetics, which severely limits performances of fuel cells and metal-air batteries. Therefore, it is of key importance to find an efficient and stable electrocatalyst to promote ORR. Carbon-based materials, which possess high conductivity, good stability and large specific surface area, are usually used in electrocatalytic ORR. However, pure carbon-based materials exhibit low efficiency. Coupling carbon-based materials with manganese (Mn) and cobalt (Co) transition metals containing 3d orbitals is an effective way to improve electrocatalytic performance. Herein, carbon nanofibers containing …
Research And Application Of Copper Electroplating In Interconnection Of Printed Circuit Board,
2021
1. School of Materials and Energy, University of Electronic Science and Technology of China, Chengdu 610054, Sichuan, China;
Research And Application Of Copper Electroplating In Interconnection Of Printed Circuit Board, Chong Wang, Chuan Peng, Jing Xiang, Yuan-Ming Chen, Wei He, Xin-Hong Su, Yu-Yao Luo
Journal of Electrochemistry
Copper electroplating is the key technology for manufacturing of integrated circuit, packaging substrate, printed circuit board, and other electronic interconnection components. However, the electrochemistry and mechanism of deposition growth have not been fully elucidated, and the development of additives and bath maintenance are inseparable from a large number of experiments. This article reviews recent fundamental research and application progress in copper electroplating for printed circuit board industry, and these works are mainly dedicated by the research group of Printed Circuit and Printed Electronics from University of Electronic Science and Technology of China. First of all, a brief history of copper …
Structural, Dynamic, Elastic And Electronic Properties Of Anin (A = Li, Na, Mg, Ca): First-Principles Calculations,
2021
1. Department of Physics, Xiamen University, Xiaman 361005, Fujian, China;
Structural, Dynamic, Elastic And Electronic Properties Of Anin (A = Li, Na, Mg, Ca): First-Principles Calculations, Xia-Min Huang, Li-Hong Zhang, Shun-Qing Wu, Yong Yang, Zi-Zhong Zhu
Journal of Electrochemistry
Ternary transition metal nitrides ANiN (A = Li, Na, Mg, Ca) are potential electrode materials for rechargeable batteries. The physical properties, such as the thermodynamic stability, the electronic band gap as well as the elastic stability, are important for their battery applications. Here, comparative studies are performed for the structural, dynamic, elastic and electronic properties of ANiN by the first-principles method. The calculations on the cohesive energy versus unit-cell volume and phonon spectra are employed to determine the most stable structures of ANiN. The calculated elastic constants of the most stable structures indicate that the Born-Huang criterion for the elastic …
Sailing To The Ocean Of Electrochemistry: The First Step Of Experiment,
2021
1. State Key Laboratory of Physical Chemistry of Solid Surfaces; Fujian Science and Technology Innovation Laboratory for Energy Materials of China; Engineering Research Center of Electrochemical Technologies of Ministry of Education; Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen 361005, Fujian, China;2. Department of Mechanical and Electrical Engineering, School of Aerospace Engineering, Xiamen University, Xiamen 361005, Fujian, China;
Sailing To The Ocean Of Electrochemistry: The First Step Of Experiment, Lian-Huan Han, Quan-Feng He, Dong-Ping Zhan
Journal of Electrochemistry
Electrochemistry is the science on the conversion between chemical energy and electric energy, which is realized by the structure change of the electrified surface and interface, and/or the surface and interfacial charge transfer reactions. Taking the electrochemical energy devices as example, the former is the supercapacitor where the energy storage and release are performed by the structure change of the electric double layer; the latter is the battery where the energy storage and release are performed by the redox reaction of the electrode active materials. When investigating an electrochemical system, we have to pay attentions to two issues: the surface …
Synthesis And Electrochemical Study Of Cuau Nanodendrites For Co2 Reduction,
2021
Electrochemical Technology Centre, Department of Chemistry, University of Guelph,50 Stone Road East, Guelph, Ontario N1G 2W1, Canada;
Synthesis And Electrochemical Study Of Cuau Nanodendrites For Co2 Reduction, Dylan Siltamaki, Shuai Chen, Farnood Rahmati, Jacek Lipkowski, Ai-Cheng Chen
Journal of Electrochemistry
The conversion of carbon dioxide (CO2) to carbon monoxide (CO) and other value-added products is an interesting approach for carbon-containing fuel synthesis using renewable and clean energy. The electrochemical reduction of CO2 is one of the promising strategies for the storage of intermittent renewable energy resources. The development of electrocatalysts with high activity and stability is vital in the electrochemical CO2 reduction process. In this study, copper and gold alloyed (CuAu) electrodes with nanodendritic structures were synthesized using a facile electrodeposition method. The CuAu nanodendrites with the atomic ratio of Cu to Au being approximately 1:1 …
Progress Of Lithium-Ion Transport Mechanism In Solid-State Electrolytes,
2021
1. School of Advanced Materials, Shenzhen Graduate School, Peking University, Shenzhen 518055, Guangdong, China;2. School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, Guangdong, China;
Progress Of Lithium-Ion Transport Mechanism In Solid-State Electrolytes, Bing-Kai Zhang, Lu-Yi Yang, Shun-Ning Li, Feng Pan
Journal of Electrochemistry
Inorganic crystalline solid electrolytes exhibit exceptional room-temperature ionic conductivities, giving them the potential to enable all-solid-state lithium (Li) - ion batteries. Developing new high-performance electrolytes is one of the most critical challenges to realize solid-state batteries, which requires understanding how chemistry facilitates fast ionic conduction and what the Li-ion migration mechanism is in inorganic solid electrolytes. In this review, we aim to summarize recent fundamental research progress in Li-ion transport, including crystal structure, behavior of ion migration (i.e., single-ion jump and multi-ions cooperative migration), and the relationship between ion migration and microstructure.
Generally, ion transport in crystalline structure can be …
Studies And Progresses On Hole Metallization In High-Density Interconnected Printed Circuit Boards,
2021
College of Chemistry and Chemical Engineering, State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen 361005, Fujian China;
Studies And Progresses On Hole Metallization In High-Density Interconnected Printed Circuit Boards, Zhao-Yun Wang, Lei Jin, Jia-Qiang Yang, Wei-Qing Li, Dong-Ping Zhan, Fang-Zu Yang, Shi-Gang Sun
Journal of Electrochemistry
Printed circuit boards (PCBs) are almost the core components of all electronic systems. With the rapid development of sciences and technologies, PCBs are gradually developing in the direction of multi-layer, thin and high-density wiring due to the functionalization, miniaturization, lightweight and high reliability of electronic products, as well as the widespread popularization of the subminiature package such as chip scale package (CSP) and ball grid array (BGA). Therefore, High-density interconnected printed circuit boards (HDI-PCBs) arise. Hole metallization is one of the core technologies in HDI-PCBs and includes two processes composed of conductive treatment and electron electroplating. Electroless copper plating, as …
Design And Fabrication Of The Electrolytic Cell With Silicon-Based Boron-Doped Diamond Electrode And Its Feasibility ForIn-Situ Nuclear Magnetic Resonance Study,
2021
1. College of Chemistry and Chemical Engineering, Xiamen University Xiamen 361005 Fujian, China;
Design And Fabrication Of The Electrolytic Cell With Silicon-Based Boron-Doped Diamond Electrode And Its Feasibility ForIn-Situ Nuclear Magnetic Resonance Study, Hao Peng, Hui-Jun Sun, Zhi-You Zhou, Lin-Fan Shen, Long Huang, Shuo-Hui Cao, Shi-Gang Sun
Journal of Electrochemistry
In-situ EC-NMR technique can be used to monitor the electrochemical reaction process in real-time and to explain the reaction mechanism at the molecular level, which is a promising and non-destructive online detection technology. This article for the first time reports the design and production of in-situEC-NMR three-electrode single-chamber electrolytic cell using silicon-based boron-doped diamond (Si/BDD) as the working electrode. Research shows that the geometric size of Si/BDD electrode being 12.5 mm 1.2 mm 0.5 mm in the NMR detection zone is small and the thickness of the electrode material is thin, which accounts for the less hindrance …
Ohmic Drop Compensation In Electrochemical Measurement,
2021
Hefei National Laboratory for Physical Sciences at the Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei, 230026, China;
Ohmic Drop Compensation In Electrochemical Measurement, Jia-Qi Chen, Xu-Xu Ye, Ling-Wen Liao, Zhen Wei, Mian-Le Xu, Yan-Xia Chen
Journal of Electrochemistry
The solution resistance (Ru) between the working electrode (WE) and the reference electrode (RE) may lead to significant Ohmic drop (iRu) and deviation of actually applied potential at the WE to the desired ones in electrochemical measurement. In the case of high current or large Ru, iRu compensation is imperative. Errors associated with insufficient compensation of theiRu drop may significantly affect the accuracy of data measured by conventional electrochemical methods, which may consequently result in wrong judgment and conclusions. In this article, we discuss important factors which may affect the accuracy of …
Recent Advances In Glycerol Electrooxidation On Pt And Pd: From Reaction Mechanisms To Catalytic Materials,
2021
1. Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Collaborative Innovation Center of Chemistry for Energy Materials, Department of Chemistry, Fudan University, Shanghai 200438, China;
Recent Advances In Glycerol Electrooxidation On Pt And Pd: From Reaction Mechanisms To Catalytic Materials, Wei-Yi Zhang, Xian-Yin Ma, Shou-Zhong Zou, Wen-Bin Cai
Journal of Electrochemistry
The conversion of glycerol to value-added products has received considerable attention recently because the booming biodiesel industry produces a large amount of glycerol as a byproduct. Among various means, electrocatalytic oxidation of glycerol is appealing owing to its environmental friendliness and high efficiency. However, electrooxidation of glycerol is very complex, involving multiple electron and proton transfer processes with many reaction pathways. How to rationally design catalysts with high selectivity toward targeted products is an overarching challenge, and of both fundamental and practical significance. In this minireview we aim to provide an overview of recent advancements in electrooxidation of glycerol focusing …
Investigation On The Structure And Dynamics Of Lithium Ion Solvation Shell By Linear And Non-Linear Infrared Spectroscopy,
2021
Louisiana State University and Agricultural and Mechanical College
Investigation On The Structure And Dynamics Of Lithium Ion Solvation Shell By Linear And Non-Linear Infrared Spectroscopy, Xiaobing Chen
LSU Doctoral Dissertations
Lithium ion battery (LIB) is a lightweight, rechargeable and powerful battery that is used widely from mobile phones to laptops to electric cars. It has many exceptional advantages such as high energy density, high output power, relatively low self-discharge, etc. However, it has some disadvantages such as safety issues, capacity loss, and expensive manufacture. LIB is composed of three main components: electrolytes, positive and negative electrodes. Researchers have been working on improving the performance of LIB for the past decade, but only a few have focused on investigating the electrolytes at the molecular level. In addition, the molecular mechanisms behind …
