A Grand Unified Model For Liganded Gold Clusters,
2016
University of Nebraska-Lincoln
A Grand Unified Model For Liganded Gold Clusters, Wen Wu Xu, Beien Zhu, Xiao Cheng Zeng, Yi Gao
Xiao Cheng Zeng Publications
A grand unified model (GUM) is developed to achieve fundamental understanding of rich structures of all 71 liganded gold clusters reported to date. Inspired by the quark model by which composite particles (for example, protons and neutrons) are formed by combining three quarks (or flavours), here gold atoms are assigned three ‘flavours’ (namely, bottom, middle and top) to represent three possible valence states. The ‘composite particles’ in GUM are categorized into two groups: variants of triangular elementary block Au3(2e) and tetrahedral elementary block Au4(2e), all satisfying the duet rule (2e) of the valence shell, akin to …
Subtractive Methods To Form Pyrite And Sulfide Nanostructures Of Fe, Co, Ni, Cu And Zn,
2016
West Chester University of Pennsylvania
Subtractive Methods To Form Pyrite And Sulfide Nanostructures Of Fe, Co, Ni, Cu And Zn, Kurt W. Kolasinski
Chemistry Faculty Publications
The low Z metals Fe, Co, Ni, Cu and Zn are Earth abundant, i.e. inexpensive, and their sulfides are of low toxicity. This makes them appealing candidates for materials applications requiring semiconductors or, in the case of CoS2, a metal since they can potentially be produced in large quantities and low cost. Though of great potential little work has explored how subtractive methods can be used to form nanostructured and/or porous structures in, e.g. FeS2, CoS2, NiS, Cu2S and ZnS.
Design And Synthesis Of Novel Octacarboxy Porphyrinic Metal–Organic Frameworks,
2016
University of Nebraska-Lincoln
Design And Synthesis Of Novel Octacarboxy Porphyrinic Metal–Organic Frameworks, Jacob A. Johnson
Department of Chemistry: Dissertations, Theses, and Student Research
Metal-Organic Frameworks (MOFs) are a class of nanoporous crystalline materials constructed via the interconnection between metal-ions/inorganic clusters and organic ligands. Since the surface area, pore size and distribution, and chemical functionalities of MOFs are highly tunable via the judicious combinations of inorganic clusters and organic ligands, MOFs have attracted intensive interests for a variety of applications including gas adsorption and separation, catalysis, chemical sensing, and drug delivery among others. Porphyrin based ligands are of particular interest for building functional MOFs due to their unique photo-, electro-, and catalytic properties. In addition, the four-fold symmetry of porphyrin ligands offers an effective …
Design And Synthesis Of Dynamic Covalent Polymer Scaffolds With Controlled Architectures,
2016
University of Southern Mississippi
Design And Synthesis Of Dynamic Covalent Polymer Scaffolds With Controlled Architectures, Emily Annette Hoff
Dissertations
The design and synthesis of functional, controlled polymer architectures is essential to the development of new materials with precise and tailorable properties or applications. The work described in this dissertation focuses on the development of controlled polymer architectures with dynamic linkages for the design of multifunctional materials and surfaces via robust, efficient, and stimuli-responsive strategies.
In Chapter III, a post-polymerization modification strategy based on ambient temperature nucleophilic chemical deblocking of polymer scaffolds bearing N-heterocycle blocked isocyanate moieties is reported. Room temperature RAFT polymerization of three azole-N-carboxamide methacrylates, including 3,5-dimethyl pyrazole, imidazole, and 1,2,4-triazole derivatives, afforded reactive polymer scaffolds …
Electrogenerated Chemiluminescence Study Of Semiconductor Nanoparticles Towards Sensitive Detection Of Biomolecules,
2016
University of Southern Mississippi
Electrogenerated Chemiluminescence Study Of Semiconductor Nanoparticles Towards Sensitive Detection Of Biomolecules, Yiliyasi Wusimanjiang
Dissertations
The main focus of this dissertation is to unfold the fundamental aspects of electrogenerated chemiluminescence (ECL) generation from semiconductor nanoparticles (also known as quantum dots or QDs) within different ECL systems. The ECL and photo-physical interactions between the CdTe QDs (λemission= ~760 nm) and the CdSe QDs (λemission= ~550 nm), as well as the effects of carbon nanotubes on ECL of QDs were separately investigated. Optimum experimental conditions for peptide bond formation on an electrode surface through EDC (1-ethyl-3-(-3-dimethylaminopropyl) carbodiimide hydrochloride)/NHS (N-Hydroxysulfosuccinimide) coupling were also revealed using cyclic voltammetry technique. Based on the information …
Role Of The Inner Shell Architecture On The Various Blinking States And Decay Dynamics Of Core-Shell And Core-Multishell Quantum Dots,
2016
University of Arkansas, Fayetteville
Role Of The Inner Shell Architecture On The Various Blinking States And Decay Dynamics Of Core-Shell And Core-Multishell Quantum Dots, Pooja Bajwa
Graduate Theses and Dissertations
Colloidal semiconductor nanocrystals (quantum dots, QDs) have received much attention in recent years due to their uniquely size-tunable properties leading to a number of promising applications. Some of their most popular applications include their use as fluorescent probes in biology, as electro-optical components and in photovoltaic devices. CdSe-based QDs are particularly important because of their ease of synthesis, high photoluminescence quantum yields (PL QYs) across the whole visible spectrum and their photostabilty. Shelling of core QDs is usually carried out to improve their optical properties, minimize outer environmental effects on their properties, and avoid toxic element exposure to the environment. …
Preparation Of Aminoalcohols And Their Application For The Synthesis Of Heterocycles And As Potential Sensors For Nerve Agents,
2016
Western Michigan University
Preparation Of Aminoalcohols And Their Application For The Synthesis Of Heterocycles And As Potential Sensors For Nerve Agents, David L. Sellers
Dissertations
Oxazoles and oxazolines are important heterocyclic scaffolds commonly used in pharmaceuticals and optoelectronic materials. Traditionally these heterocyclic compounds are prepared by condensation methodology that suffers from poor reactivity when using electron deficient or sterically crowded reaction partners. Condensation methods also exhibit low tolerance of many functional groups as the reactions typically use strong acids and high temperatures. This dissertation describes an alternate strategy for the formation of these compounds by employing an epoxide opening followed by oxidation to form these heterocyclic compounds.
Epoxide opening reactions with primary aliphatic, allylic, and benzylic amines, aminolysis reactions, often achieve high yields regardless of …
Graphene Quantum Dots Electrochemistry And Development Of Sensitive Electrochemical Biosensor [Hybrid Poster 1-B],
2016
Western Kentucky University
Graphene Quantum Dots Electrochemistry And Development Of Sensitive Electrochemical Biosensor [Hybrid Poster 1-B], Tyler Smith, Alexander Banaszak
Posters-at-the-Capitol
Graphene quantum dots (GQDs) are zero-dimensional material derived from graphene derivatives with characteristics from the structure of graphene with quantum confinement and edge effects possessing unique properties. Intense research activity in GQDs is attributed to their novel physical-chemical phenomena arising from the sp2-bonded carbon core surrounded with edge functional moieties. In this work, GQDs of optimal 5-7 nm size are investigated for their fundamental electrochemical properties and use in electrochemical sensing including enzyme-based glucose biosensor. Glucose oxidase (GOx) was immobilized on GQDs modified glassy carbon (GC) and the UV-Vis absorption and fluorescence spectroscopy, electron microscopy, cyclic …
Molecular Sensitivity And Selectivity Of Metal Nanoparticles Decorated Graphene As ‘Smart’ Surface-Enhanced Raman Scattering (Sers) Platforms [Hybrid Poster 1-A],
2016
Western Kentucky University
Molecular Sensitivity And Selectivity Of Metal Nanoparticles Decorated Graphene As ‘Smart’ Surface-Enhanced Raman Scattering (Sers) Platforms [Hybrid Poster 1-A], Alexander Banaszak, Tyler Smith
Posters-at-the-Capitol
Raman scattering signal enhancement that uses graphene as support, graphene-enhanced Raman scattering (GERS), is a recent phenomenon. It can produce clean and reproducible Raman signals of chemical molecules with significantly enhanced signal intensity in contrast to traditional surface- (SERS) and tip- enhanced Raman scattering (TERS) techniques. While enhancement in SERS and TERS arise due to the electromagnetic mechanism, GERS also relies on a chemical mechanism and therefore shows unique molecular sensitivity and selectivity. In this work, we developed graphene materials decorated with noble metal (silver and gold) nanoparticles for detection of different chemical molecules e.g. methylene blue (MB) and rhodamine …
Micro/Nano-Structured Electrode Materials For Sodium-Ion Batteries,
2016
Key Laboratory of Electromagnetic Processing of Materials (Ministry of Education), College of Metallurgy, Northeastern University, Shenyang 110819, China;Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China;
Micro/Nano-Structured Electrode Materials For Sodium-Ion Batteries, Shuang Yuan, Yun-Hai Zhu, Sai Wang, Tao Sun, Xin-Bo Zhang, Qiang Wang
Journal of Electrochemistry
Sodium has similar physics and chemical properties to lithium, alternatively, sodium (Na)-ion batteries have again aroused a great deal of interest recently, particularly for large-scale stationary energy storage applications due to the practically infinite sodium resources and low cost. However, the technics and materials for Na-ion batteries are immature. Therefore, development of advanced anode and cathode materials for Na-ion batteries is urgently desired but remains a great challenge. This paper briefly reviews some recent progresses in this field, addressing the morphology effects, as well as functions of carbon composite materials toward Na-ion batteries. Several electrode materials with micro/nano-structures based on …
Research Progress In Cycle Stability Of Silicon Based Li-Ion Battery Anodes,
2016
State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China;
Research Progress In Cycle Stability Of Silicon Based Li-Ion Battery Anodes, Ze-Liang Guo, Hui Wu
Journal of Electrochemistry
Silicon(Si), with the highest specific capacity currently known, is a promising anode material for Li-ion battery. However, in the charging and discharging process, with Li atoms inserting into and breaking out of the Si crystal lattices, the Si anode undergoes enormous volume expansion and contraction, ending in pulverization. The fact that the specific capacity of bulk Si anodes drop quickly is a challenging problem. In this review, we summarize recent progresses in Si anode. We concern about the nanostructure of silicon, cooperation of silicon with other additives and macrostructure design of anodes. We discuss strengths and shortcomings of different methods, …
Electrochemical Performance Of Crystalline Li12Si7 As Anode Material For Lithium Ion Battery,
2016
State Key Laboratory of Silicon Materials, Key Laboratory of Advanced Materials and Applications for Batteries of Zhejiang Province and School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China;
Electrochemical Performance Of Crystalline Li12Si7 As Anode Material For Lithium Ion Battery, Ya-Xiong Yang, Rui-Jun Ma, Ming-Xia Gao, Hong-Ge Pan, Yong-Feng Liu
Journal of Electrochemistry
Crystalline Li12Si7 is successfully synthesized by heating the mixture of LiH and Si with a molar ratio of 12:7, which avoids the huge difference of the melting points between Li and Si. The electrochemical performance and lithium storage mechanism of the as-prepared Li12Si7 are studied in this work. It is found that only a change in cell volume takes place without a phase change during the lithiation/delithiation of Li12Si7 at a voltage range of 0.02 ~ 0.6 V, exhibiting a solid-solution lithium storage mechanism. Such a lithium storage process effectively retards the volume effect …
Continuous Synthesis And Condition Exploration Of Precursor Ni1/3Co1/3Mn1/3(Oh)2 Ternary Cathode Material,
2016
Zibo Guoli New Power Source Technology Co., Ltd., Zibo, Shandong 255086, China; Zibo Engineering Technology Research Center of Asymmetric Large Power Capacitor Battery, Zibo, Shandong 255086, China;
Continuous Synthesis And Condition Exploration Of Precursor Ni1/3Co1/3Mn1/3(Oh)2 Ternary Cathode Material, Zhi-Jun Jiang, Ya-Li Zhang, Qian Wang, Hui Zhang
Journal of Electrochemistry
Commercial LiNi1/3Co1/3Mn1/3(OH)2 ternary material is generally prepared by a combination of co-precipitation and solid state reaction method. The particle size distribution and morphology of Ni1/3Co1/3Mn1/3(OH)2 precursor have a great impact on the electrochemical performance of LiNi1/3Co1/3Mn1/3O2. In this work, the precursor Ni1/3Co1/3Mn1/3(OH)2 ternary cathode material was prepared by co-precipitation method with MnSO4, NiSO4, and CoSO4 as raw materials, NaOH as a precipitating agent and NH3 …
Research And Application Of Key Materials For Sodium-Ion Batteries,
2016
Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), College of Chemistry, Nankai University, Tianjin 300071, China;
Research And Application Of Key Materials For Sodium-Ion Batteries, Yong-Chang Liu, Cheng-Cheng Chen, Ning Zhang, Liu-Bin Wang, Xing-De Xiang, Jun Chen
Journal of Electrochemistry
Sodium-ion batteries (SIBs) have been considered as a potential large-scale energy storage technology owing to the abundance, wide distribution, and low price of sodium resources. However, the larger and heavier sodium ion as compared to lithium ion makes it difficult to identify appropriate electrode materials with the capability for fast and stable sodium-ion insertion/extraction. Furthermore, the optimization of electrolyte, the matching of cathode and anode materials, and the construction of sodium-ion full batteries with high-performance, high-safety, and low-cost are urgently needed in order to make SIBs commercially available. This review summarizes the up-to-date research progresses in key materials (including cathode, …
Advances And Prospects Of Lithium-Sulfur Batteries,
2016
Department of Chemistry, Fudan University, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Institute of New Energy, IChEM (Collaborative Innovation Center of Chemistry for Energy Materials), Shanghai 200433 , P.R. China;
Advances And Prospects Of Lithium-Sulfur Batteries, Shou-Yi Yuan, Ying Pang, Li-Na Wang, Yong-Gang Wang, Yong-Yao Xia
Journal of Electrochemistry
Lithium-sulfur batteries have recently attracted worldwide attention due to the high specific theoretical energy density of sulfur cathode (2600 Wh⋅kg-1), low cost and wide availability of sulfur. However, the practical application of lithium-sulfur batteries has been hindered by several challenges, such as the shuttling of polysulfide intermediates, the large volume expansion of sulfur during charge/discharge and the dendrites formation on lithium anode. Foremost among these is the shuttling effect arising from the dissolution of lithium polysulfides intermediate into the electrolyte from the cathode reaction and their diffusion to the anode where they react with metal lithium to form …
Research Progress Of Si-Based Anode Materials For Lithium-Ion Batteries,
2016
State Key Laboratory of Physical Chemistry of Solid Surfaces, State-Province Joint Engineering Laboratory of Power Source Technology, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian, China;
Research Progress Of Si-Based Anode Materials For Lithium-Ion Batteries, Ding-Qiong Chen, Yang Yang, Qiu-Li Li, Jin-Bao Zhao
Journal of Electrochemistry
Owing to its high theoretical specific capacity (4200 mAh·g-1), silicon is a promising candidate to replace graphite as the anode in lithium ion batteries (LIBs). However, low intrinsic electric conductivity and dramatic volume change (~ 300%) during the process of lithiation and delithiation result in electrode pulverization and capacity loss with cycling, accordingly, the application of silicon as an anode in LIBs has been severely hindered. We will discuss the structure of silicon electrode including synthesis of Si-based composites,the selection of binder for silicon and the fabrication of binder-free Si-based electrode, as well as the electrolyte additive to …
Template-Assisted Hydrothermal Synthesis Of Nio@Co3O4 Hollow Spheres With Hierarchical Porous Surfaces For Supercapacitor Applications,
2016
MOE Laboratory of Bioinorganic and Synthetic Chemistry, KLGHEI of Environment and Energy Chemistry, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275, China;
Template-Assisted Hydrothermal Synthesis Of Nio@Co3O4 Hollow Spheres With Hierarchical Porous Surfaces For Supercapacitor Applications, Wen Zhou, Xue-Feng Lu, Ming-Mei Wu, Gao-Ren Li
Journal of Electrochemistry
Hollow structures have shown great potentials in a variety of important applications, such as energy conversion and storage. In order to further enhance the performance, the rational design of hollow structures with higher complexity in terms of composition and structure is highly desirable and still remains a great challenge. In this work, an efficient strategy was established for the fabrication of novel NiO@Co3O4 hollow spheres (HSs) with hierarchical porous surfaces by silica spheres template-assisted hydrothermal synthesis. The as-fabricated NiO@Co3O4 HSs showed high specific surface area of 219.68 m2·g-1, and significant …
Effects Of Lithium Salts On The Properties Of Hyperbrandched/Comb-Like Composite Polymer Electrolytes,
2016
School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275,China;Guangzhou Tinci Materials Technology Co., Ltd., Guangzhou 510600, China;
Effects Of Lithium Salts On The Properties Of Hyperbrandched/Comb-Like Composite Polymer Electrolytes, Xian-Lei Hu, Xiao-Xu Liang, Ming-Qiu Zhang, Ruo-Xin Zhang, Li-Ping Zhang, Wen-Hong Ruan
Journal of Electrochemistry
Based on the chemical characteristics of the hydroxyl group of PVA side-chain, the hyperbrandched poly(amine-ester) (HBPAE) was used to hypergraftingly pretreated nano-silica (SiO2) and polyving akohol (PVA). And different lithium salts were added to fabricate the SiO2-g-HBPAE/PVA-g-HBPAE hyperbrandched/comb-like composite polymer electrolytes (CPEs). The dispersion of nanoparticles in matrix was observed by SEM. The effects of different lithium salts on the properties of CPEs were studied by DSC, tensile test and dielectric spectra. The results showed that the hypergrafting method improved the interphase compatibility between SiO2 and matrix. Sulfonic acid type lithium salts accelerated self-plasticizing with …
The Study Of Dynamical Electrochemical Impedance Spectroscopy For Oxygen Reduction Reaction On Pt/C Catalyst,
2016
College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266003,Shandong, China;Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China;
The Study Of Dynamical Electrochemical Impedance Spectroscopy For Oxygen Reduction Reaction On Pt/C Catalyst, Kun-Ming Shi, Jian-Wei Guo, Jia Wang
Journal of Electrochemistry
With joint techniques of rotating disc electrode(RDE) and electrochemical impedance spectroscopy(EIS), and further establishment on equivalent circuit model, this paper studied oxygen reduction reaction(ORR) on commercial Pt/C catalyst in acid medium. Our results found that the dynamical interface on Pt/C consists of two independent processes: 1) the PtO reduction from Pt surface, 2) the new PtO formation from ORR, thus providing key clues for catalyst stability and activity. This also implied that the dynamical interface facilitates reconstruction for porous electrode, and matches with mass transfer. One important issue is discovered that at high overpotential, the high reaction rate for ORR …
Effects Of Sintering Parameters On The Microstructure And Tensile Properties Of In Situ (Ti5si3 + Tibw)/Ti6al4v Composites With Two-Scale Network Architecture,
2016
Harbin Institute of Technology
Effects Of Sintering Parameters On The Microstructure And Tensile Properties Of In Situ (Ti5si3 + Tibw)/Ti6al4v Composites With Two-Scale Network Architecture, Yang Jiao, L. J. Huang, L. Geng
The 8th International Conference on Physical and Numerical Simulation of Materials Processing
No abstract provided.
