Materials Chemistry Commons^™

Synthesis Of Healable Organic Semiconductor Through Dioxaborolane Bond, Junchen Liu, William W. Mcnutt, Jianguo Mei

The Summer Undergraduate Research Fellowship (SURF) Symposium

The field of organic semiconductors have gained enormous attention the past few decades. Organic materials offer numerous advantages over their inorganic counterparts. Recently a number of works have demonstrated organic semiconductors with healable properties. We aim to investigate the healable ability of an organic semiconductor by mimicking a vitrimer system through the reversible dioxaborolane bond. Vitrimers are polymers with reversible crosslink system. It has been reported that the use of the borane-oxygen bond as the crosslink showed good mechanical performance. The electrical properties will be inspected for the vitrimer-like polymer. In this report we describe a Diketopyrrolopyrrole base polymer incorporating …

How Strongly Do Oysters Stick?, Nicolás M. Morato, Andrés M. Tibabuzo, Jonathan J. Wilker

The Summer Undergraduate Research Fellowship (SURF) Symposium

Biological adhesives are a type of interfacial material that has incredible potential to generate new biomimetic compounds that can replace current strong, but toxic, adhesives. Therefore, a study of the chemical composition and mechanical properties of those bio-adhesives is necessary. However, in the case of oysters, despite known chemical characterization of the adult’s adhesive, there are almost no studies on its mechanical properties. Furthermore, there is no available information on the adhesive properties of spat (oysters in their larvae state). Herein, we present the first mechanical characterization of the spat adhesive, measuring its adhesion strength by hydrodynamic determination using a …

Temperature-Dependent Exciton Dynamics Of Superacid Treatment In Monolayers Of The Metal Dichalcogenide Mos2, Mingwei Zhou, Long Yuan, Jordan Snaider, Libai Huang

The Summer Undergraduate Research Fellowship (SURF) Symposium

To improve optoelectronic semiconductor materials, one of the most efficient research areas is the two-dimensional (2D) transition-metal dichalocogenides (TMDCs). It has been shown that organic nonoxidizing superacid bis(trifluoromethane)sulfonamide (TFSI) treatment of molybdenum disulfide (MoS₂) monolayer could uniformly enhance its photoluminescence by more than two orders of magnitude and also extend the lifetime of excitons. This could greatly improve the efficiency of the solar energy usage, but the mechanism behind it has not been fully understood. Extreme low temperatures (approximately 7K), which slow the surface exciton mobility, were applied to investigate the changes of treated MoS₂ monolayer surfaces. …

Usage Of Fomblin Y To Improve Water Repellence Of Surface Coatings, Shawn Pj Kirby, Jeffrey Alston, Andrew Guenthner

STAR Program Research Presentations

Fluoro-Decyl POSS (FDP) has shown strong potential as a water repellant surface coating. Additionally, Fomblin is a solvent believed to have the ability to control the crystallization of POSS compounds on surfaces. Controlling the crystallization is key to improving water repelling abilities of surfaces. Thus, dip coating FDP and Fomblin onto surfaces is being investigated for water repulsion, mechanical stability, and deposition feasibility. First, temperature dependence of solubility of Fluoro-Decyl POSS in Fomblin was tested using Dynamic Light Scattering. Relative water repelling abilities of different coatings were determined by measuring contact angle of surfaces with water. Coatings with and without …

Comparative Solubility Of Poss Compounds In Fomblin Y, Shawn Pj Kirby, Jeffrey Alston, Andrew Guenthner

STAR Program Research Presentations

Fluoro-Decyl POSS (FDP) has shown strong potential as a water repellant surface coating. Additionally, Fomblin is a solvent believed to have the ability to control the crystallization of POSS compounds on surfaces. Controlling the crystallization is key to improving water repelling abilities of surfaces. Thus, dip coating FDP and Fomblin onto surfaces is being investigated for water repulsion, mechanical stability, and deposition feasibility. However, in order for this to be successful, POSS must be soluble in Fomblin. Temperature dependence of solubility of Fluoro-Hexyl, Fluoro-Octyl, Fluoro-Decyl POSS in Fomblin was tested using Dynamic Light Scattering. The values were compared, and it …

Cellulose Reinforced Thermoplastic Composites By In-Situ Ring-Opening Polymerization, Shahab Kashani Rahimi

Dissertations

Over the past two decades, the increasing concern about the negative environmental impacts of synthetic materials has led to rising interests in utilizing renewable natural resources to develop polymer materials with comparable properties and performance to their synthetic counterparts. One of the major fields of interest is polymer composites where the replacement of synthetic fibers with bio renewable natural fibers is of great potential. However, the processing difficulties, in terms of fiber dispersion and thermal stability have limited the application of cellulosic fibers to polymers with low processing temperatures which are mostly hydrophobic polymers. As a result, the true reinforcing …

Anodic Nanocatalysts For Formic Acid Fuel Cells: An Electrochemical Study, Tamanna F. Shanta Mcfarland

Dissertations

Direct formic acid fuel cells (DFAFCs) have been reported as a prominent source of alternative green energy and solution to imminent energy crisis for the last two decades. The challenge to commercialize DFAFCs is primarily the utilization of cost effective, high performance and durable anodic catalyst for formic acid oxidation (FAO). Consequently, this dissertation addresses the extensive electrochemical study of a number of nanomaterials towards the potential use as electrocatalysts for FAO. Morphology and elemental analyses of the prepared nanomaterials were obtained using electron microscopy techniques.

After a general introduction and overall review of this dissertation (Chapter I), studies of …

Water-Soluble Pd And Pd-Alloy Nanoparticles As Catalysts In Biphasic Solvent., Shekhar Bhama

Electronic Theses and Dissertations

This dissertation shows the chemical synthesis of Pd and Pd-alloy nanoparticles (NPs) and their hydrogen and thermal stabilities for applications in the homogeneous and pseudo-homogeneous catalysis of organic reactions. Mainly, this dissertation describes 1) the chemical synthesis of Pd, PdPt, PdAu and Cu-Pd core-shell NPs coated with various organic ligands (thiols, amines and citrate), with different metal compositions in different synthetic environment, 2) the stability of solutions containing various NPs in the presence of hydrogen or varying temperatures, 3) the evaluation of the catalytic activity of Pd, PdPt, PdAu and CuPd NPs for hydrogenation/isomerization of allylic alcohols, and 4) the …

Controlled Electrochemical Synthesis Of Single One-Dimensional Metal Nanochains Across Microgap Electrodes., Amareshwari Konutham

Electronic Theses and Dissertations

This study mainly focuses on the fabrication of single one dimensional (1D) NP chains across the 5-micron gap of Au two electrode devices (TED). This has been achieved by electrochemical deposition of Ag onto the two electrodes, soaking the TED in 0.1 M Cetyltrimethyl ammonium bromide for 2-3 hours, and then close monitoring of the current as a function of time while a voltage across the two Ag coated Au electrodes in air. One dimensional Ag nanoparticle chain formation occurred by oxidation of Ag to Ag⁺ at the positive electrode followed by movement of Ag⁺ ions to the …

Transient Absorption Studies Of Cdse Nanocluster Passivated With Phenyldithiocarbamate Ligands., Yizhou Xie

Electronic Theses and Dissertations

Semiconductor nanocluster (SCNC) research is a rapidly growing field driven by the promising fact that properties of such materials can be tailored by modifying their size, shape, and structure. Combination of nanocluster and organic ligands provides even wider possibilities of design and development of effective and task-specific nanostructures. Understanding of and, eventually, control of energetics, interfacial interaction, and photoinduced processes in such highly heterogeneous structures is critical to invention of novel materials including those in photovoltaic devices. In the newly established Ultrafast Laser Facility (ULF), transient absorption pump-probe spectroscopy (TAPPS) has been employed to investigate the electron transfer (ET) and …

Synthesis,Structure And Properties Of Ruthenium Polypyridyl Metalloligand Based Metal-Organic Frameworks, Mamatha Polapally

Masters Theses & Specialist Projects

Metal-organic frameworks (MOFs) have been extensively studied because of their amazing applications in gas storage, purification, photocatalysis, chemical sensing, and imaging techniques. Ruthenium polypyridyl complexes have been broadly considered as photosensitizers for the conversion of solar energy and photoelectronic materials. With this aspect, we have synthesized three new ruthenium polypyridyl based MOFs ([Ru(H2bpc)Cu(bpc)(Hbpc)2(H2O)]·5H2O (1), [Ru(H2bpc)(Fe(bpc)(Hbpc)2(H2O)2]·6H2O (2) and [Ru(H2bpc)Ni(bpc)(Hbpc)2(H2O)2]·6H2O (3)) from ruthenium(III) chloride, bpc (2,2’- bipyridine-4,4’-dicarboxylic acid) ligand, and 3d M(II) metal ions (M(II)= Cu(II), Fe(II), Ni(II)). These MOFs were synthesized under hydro or solvothermal conditions by using water, ethanol or methanol as solvents. The crystal structures of the new compounds …

Ionic Thermoelectric Paper, Fei Jiao, Ali Naderi, Dan Zhao, Joshua Schlueter, Maryam Shahi, Jonas Sundström, Hjalmar Granberg, Jesper Edberg, Ujwala Ail, Joseph W. Brill, Tom Lindström, Magnus Berggren, Xavier Crispin

Physics and Astronomy Faculty Publications

Ionic thermoelectric materials, for example, polyelectrolytes such as polystyrene sulfonate sodium (PSSNa), constitute a new class of materials which are attracting interest because of their large Seebeck coefficient and the possibility that they could be used in ionic thermoelectric SCs (ITESCs) and field effect transistors. However, pure polyelectrolyte membranes are not robust or flexible. In this paper, the preparation of ionic thermoelectric paper using a simple, scalable and cost-effective method is described. After a composite was fabricated with nanofibrillated cellulose (NFC), the resulting NFC–PSSNa paper is flexible and mechanically robust, which is desirable if it is to be used in …

Wastewater Treatment Process Based On Microbial Electrochemistry: Opportunities And Challenges, Wei-Hua He, Jia Liu, Hai-Man Wang, Yu-Jie Feng

Journal of Electrochemistry

Microbial electrochemical technology (MET) has drawn great attention for its characteristics of synergetic pollution removal and energy recovery of wastewater. In the last decade, significant developments in microbial electrochemical system (MES) have been made in the aspects of electron transfer mechanism, microbial community analysis, function expansion, low-cost electrode materials and scaled-up constructions. However, the feasibility of MET as a wastewater treatment process has been controversial so far. In this paper, the characteristics of MET were systematically compared with anaerobic and aerobic processes from the application point of view in the aspects of pollution degradation and energy recovery processes. The MET-based …

Ionic Liquid-Supported Tempo/Polymeric Ionic-Liquid/Carbon Black Ternary Composites: Preparations And Applications In Electrochemical Oxidation Of Alcohols, Xin Lin, Cao-Cao Sun, Zhi-Rong Liu, Cheng-Chu Zeng

Journal of Electrochemistry

To effectively recover redox catalyst and supporting electrolyte, a novel ternary composite consisting of ionic liquid-supported TEMPO, polymeric ionic-liquid and carbon black was prepared. The ionic-liquid supported redox catalyst TEMPO-IL-BF₄ was firstly synthesized from 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl, and followed by the reaction of polydimethyldiallylammonium chloride (PDDA) and bis(trifluoromethane)sulfonimide lithium salt (LiTFSI) to form poly[diallyldimethylammonium bis(trifluoromethanesulfonyl)imide] (PDDA(Tf₂N)). A combination of the above mentioned two synthesized materials and carbon black afforded to obtain the ternary composite, which was used as the recoverable supporting electrolyte and mediator for the electrochemical oxidation of alcohol. The results indicate that various alcohols could be oxidized …

Electrochemical Synthesis Of Homoallylic Alcohols And Homoallylic Amines, Wei-Qiang Zhong, Xiang-Hui Liang, Jing-Mei Huang

Journal of Electrochemistry

Electrochemical technique has been widely applied in the organic synthesis. This review focuses on the electrochemical synthesis of homoallylic alcohols and homoallylic amines from the allylation of carbonyl compounds and imines. This method has been developed impressively, especially in the field of electrochemical allylation in a green solvent of aqueous media. Improvement of the efficiency of the electricity, regio-selectivity and chiral synthesis are expected.

Cathodic Electrochemiluminescence Of Meso-Tetra(4-Sulfophenyl)Porphyrin/Potassium Peroxydisulfate System, Yan-Fenga Wang, Dia Luo, Duo-Liang Shan, Xiao-Quan Lu

Journal of Electrochemistry

A new electrochemiluminescence (ECL) system in aqueous solution was constructed by using meso-tetra(4-sulfophenyl)porphyrin (TSPP) as a luminophoreand potassium peroxydisulfate (K2S2O8) as a reductive–oxidative coreactant. Upon sweeping from 0 V to -1.5 V, two cathodic ECL peaks were found simultaneously. One appeared at -0.8 V, which is corresponding to the reduction of TSPP, another at -1.2 V, that is attributed to the reduction of K2S2O8. And methylene blue could quench the ECL of TSPP effectively. In accordance with the linearity between quenching efficiency and the concentration of methylene blue, a method to determine methylene blue was established. The ECL mechanism was …

Characteristics And Mechanism For The Simons Electrochemical Fluorination Of Methanesulfonyl Fluoride, Wen-Lin Xu, Bao-Tong Li, Da-Wei Wang, Ya-Qiong Wang

Journal of Electrochemistry

The characteristics and mechanism for the Simons electrochemical fluorination processes were investigated during the electrochemical fluorination of CH₃SO₂F to CF₃SO₂F. The results showed that the reaction mechanism for the electrochemical fluorination of organic compounds to organic fluorides was the same as that of chemical fluorination processes using fluorinating agents such as CoF₃. The electrochemical fluorination in anhydrous HF was a heterogeneous process, and nickel fluorides on the surface of the nickel anode played the role of a mediator in the Simons process to transfer oxidation potential from the anode to …

Preparations And Applications Of Irsnox Electrode In Electrochemical Synthesis Of 2,5-Dichlorophenol, Xiang-Yu Ma, Xu-Guo Tu, Rui-Nan He, Ya Chen, Gui-Sheng Zhu, Shou-Yan Shao, Song Chen

Journal of Electrochemistry

The electrodes of titanium based iridium tin oxides (IrSnOx) have been prepared by traditional thermal decomposition method and further applied to the electrosynthsis of 2,5-dichlorophenol in order to explore a green and high efficient synthesis route. The results showed that the electrode surface existed apparent cracks, while the intermediate layer prepared with Sn:Sb=94:6 existed less cracks and longer life time. The main products of the electrolytic reaction were 2,5-dichlorophenol, p-chlorophenol, and 1,2,4-trichlorobenzene. The electrosynthsis yield of 2,5-dichlorophenol reached 57% and the selectivity of 2,5-dichlorophenol was as high as 93% by using the IrSnOx as an anode, which is obviously better …

Electrochemical Deposition Of Cr From Cr3+ In The Mixed Electrolyte Of [Bmim]Oac/H2O, Wei Luo, Dong-Fang Niu, Rong-Bin Du, Jun-Wei Wang, Zhu-Qing Wang, Heng Xu, Xin-Sheng Zhang

Journal of Electrochemistry

The electrochemical reduction of trivalent chromium ion (Cr³⁺) to Cr in 1-butyl-3-methylimidazolium acetate ([BMIM]OAc)-H₂O mixed electrolyte was investigated. The cyclic voltammograms showed that the electroreduction of Cr³⁺ in the mixed electrolyte occurred in a two-step process, namely, Cr³⁺ + e → Cr²⁺ and Cr²⁺ + 2e→ Cr⁰, controlled by the diffusion of Cr³⁺ to the electrode. The diffusion coefficient of Cr³⁺ was 1.2×10^-8 cm²/s at 40 ℃ obtained by Rendle-Sevcik equation. The chronoamperomograms of the Cr³⁺ electrodeposition confirmed the three-dimensional instantaneous nucleation mechanism of …

Preparations And Characterizations Of Ti/Pbo2 Electrodes Modified With Rare Earth Of Praseodymium And Pvp In Electrochemical Degradation Of Organics, Mai Xu, Feng-Wu Wang, Xian Liang, Yi-Jun Wei, Wen-Yan Fang, Chuan-Gao Zhu, Yun-Hu Hun

Journal of Electrochemistry

The titanium (Ti) based lead oxide (PbO₂) electrodes doped with praseodymium oxide (Pr₂O₃) and polyvinylpyrrolidone (PVP) were prepared by electrodeposition. The surface morphologies and structures of the as-prepared thin films were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD) technique, respectively. The results showed that the denser and more uniform coatings with smaller particles and larger surfaces were obtained by doping, which modified the micro-structure of the Ti/SnO₂-Sb₂O₃/Pr₂O₃-PVP-PbO₂ electrode. Cyclic voltammetry (CV) was also used to study the electrocatalytic activity of …