Materials Chemistry Commons^™

Sn-Doped Α-Fe2O3 Photocatalyst Containing Oxygen Vacancy For Water-Splitting, Zu-Hua Wang, Dong-Fang Niu, Hui-Cheng Li, Rong-Bin Du, Heng Xu, Xin-Sheng Zhang

Journal of Electrochemistry

The α-Fe₂O₃ nanoparticles containing oxygen vacancies were synthesized in atmospheric N₂ by dip-dropping method without a high vacuum employed before annealing. The influences of annealing atmosphere and Sn-doping on the photocatalytic performance of α-Fe₂O₃ nanoparticles were studied by annealing the photocatalyst in N₂ or air and adding SnCl₄ to the precursor directly. The results showed that the current density of Sn-doping α-Fe₂O₃ annealed in N₂ at 550 °C and 1.23 V (vs. RHE) was 35 times greater than that of pristine α-Fe₂O₃ annealed in …

Preparation And Electrochemical Properties Of Attapulgite-Supported Nitrogen-Doped Carbon@Nico2O4 Composites For Supercapacitors, Hui Wan, Zong-Rong Ying, Xin-Dong Liu, Jian-Jian Lu, Wen-Wen Zhang

Journal of Electrochemistry

In this work, the attapulgite-supported nitrogen-doped carbon (ANC) was prepared by in-situ chemically polymerizing polyaniline coating upon attapulgite, followed by high temperature heat treatment, and then NiCo₂O₄was reacted onto the surface of ANC by a combination of hydrothermal reaction and calcination to synthesize ANC@NiCo₂O₄ composites. The chemical composition and morphology of the samples were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and N₂ adsorption/desorption. The electrochemical properties were evaluated by means of constant current charge discharge (GCD) and cyclic voltammetry (CV). …

Preparations Of Mno2 Reference Electrodes For Corrosion Monitoring Of Reinforced Concrete, Li Yang, Bing Xu, Hai Wang, Ze-Hua Dong

Journal of Electrochemistry

In this work, the solid reference electrode was assemblied by using the electrochemically synthesized manganese dioxide (MnO₂) (EMD) powder, gel electrolyte and thin mortar layer for the durability evaluation of concrete. The EMD reference electrode exhibited higher potential stability (< 10 mV drift) than the chemically synthesied MnO₂ (CMD) based on half year potential tests in the saturated Ca(OH)₂ solution and hardened mortar. In addition, the EMD electrode was almost insensitive to the presences of chloride ion and corrosion inhibitor. Electrochemical impedance and polarization curves indicate that the EMD electrode had lower charge transfer resistance,higher exchange current density and lower temperature coefficient than the …

Aligning Electronic Energy Levels On The Anatase Tio2(101) Surface, Jun-Jie Zhao, Jun Cheng

Journal of Electrochemistry

As one of the most commonly-used materials for photocatalysis and solar energy conversion, titanium dioxide (TiO₂) has been extensively studied for more than 40 years. Its photoelectrochemical activity crucially depends on the band positions at the interface. In this work, the valence band maximum (VBM) and conduction band minimum (CBM) of a model TiO₂ surface are computed using the standard work function method at the level of Perdew-Burke-Ernzerhof (PBE) density functional, which are then converted to the scale of the standard hydrogen electrode (SHE) by subtracting the absolute SHE potential. Comparing with the rutile TiO₂(110) …

An Investigation In The Performance Of Lithium Sulfur Battery With A Tic Coated Separator, Jian-Hua Fang, Yong Cao, Mao-Ping Yang, Ming-Sen Zheng, Quan-Feng Dong

Journal of Electrochemistry

To improve the specific capacity and cycle stability of lithium-sulfur (Li-S) battery, a TiC/Celgard coating separator was developed and its performance in Li-S battery was investigated. The electrochemical test results confirmed that the TiC coating layer could significantly increase the capacity and cycle stability. At a high rate of 2C, it still delivered the capacity of 650 mAh·g^-1. At 0.5C, the specific capacity was maintained at 841.3 mAh·g^-1 after 100 cycles.

Direct Electrochemistry Of Glucose Oxidase Based On Ws2 Quantum Dots And Its Biosensing Application, Chen-Lu Li, Hua-Ping Peng, Zhong-Nan Huang, Yi-Lun Sheng, Pei-Wen Wu, Xin-Hua Lin

Journal of Electrochemistry

In this study, a novel electrochemical glucose biosensor has been developed by immobilizing glucose oxidase (GOx) on tungsten disulfide quantum dots (WS₂ QDs) on the surface of glassy carbon electrode (GCE). Transmission electron microscopy, UV-vis spectroscopy and cyclic voltammetry were employed to characterize the morphology, structure, and electrochemical behaviors of the as-prepared WS₂ QDs and the biofilm modified electrode. The results suggested that the WS₂ QDs could accelerate the electron transfer between the electrode and the immobilized enzyme, which enabled the direct electrochemistry of GOx without any electron mediator. Besides, the immobilized GOx in WS₂ QDsfilm …

Application Of Adamantane Schiff Base Nickel Complexes/Graphene Oxide/Glassy Carbon Modified Electrode In Detection Of Carmine, Peng Guo, Zheng Liu, Hai-Ying Li, Li-Ming Ma

Journal of Electrochemistry

The Schiff base nickel complexes/graphene oxide/glassy carbon electrodes were prepared by embedded method and electrodeposition on which were used to quantitatively detect the contents of carmine. Cyclic voltammetry, chronoamperometry, scanning electron microscopy (SEM) and other methods were employed to characterize properties and morphologies of the modified electrodes. The results show that the adamantane double Schiff base nickel complexes/graphene oxide/glassy carbon electrode had high electric catalytic activity toward carmine oxidation reaction, and might provide an easy and quick way to detect carmine content with good reproducibility.

Controlled Microfabrication Of High-Aspect-Ratio Structures In Silicon At The Highest Etching Rates: The Role Of H2o2 In The Anodic Dissolution Of Silicon In Acidic Electrolytes, Chiara Cozzi, Giovanni Polito, Kurt W. Kolasinski, Giuseppe Barillaro

Chemistry Faculty Publications

In this work the authors report on the controlled electrochemical etching of high-aspect-ratio (from 5 to 100) structures in silicon at the highest etching rates (from 3 to 10 µm min−1) at room temperature. This allows silicon microfabrication entering a previously unattainable region where etching of high-aspect-ratio structures (beyond 10) at high etching rate (over 3 µm min−1) was prohibited for both commercial and research technologies. Addition of an oxidant, namely H2O2, to a standard aqueous hydrofluoric (HF) acid electrolyte is used to dramatically change the stoichiometry of the silicon dissolution process under anodic biasing without loss of etching control …

Design Of Collagen-Mimetic Peptides, Parminder Jeet Kaur

Dissertations, Theses, and Capstone Projects

Collagen is the major component of the extracellular matrix and is involved in a wide range of cellular functions during tissue development and action. At the core of the diverse functions of this versatile protein is its remarkable ability to form supramolecular structures through self-assembly and/or through interactions with other biomolecules. One typical example of such supramolecular structure is the fibrils of collagen types I, II and III of the connective tissues. These fibrils have staggered arrangement of the laterally associated collagen triple helices – the structural unit of collagen – to form long, smooth fibrils with a characteristic 67 …

Synthesis Of Complex/Multifunctional Metal (Hydr)Oxide/Graphite Oxide/Aunps Or Agnps Adsorbents And Analysis Of Their Interactions With Chemical Warfare Agents, Dimitrios A. Giannakoudakis

Dissertations, Theses, and Capstone Projects

One of the most widely used chemical warfare agent (CWA) is mustard gas, which is a highly toxic blistering agent. In this study we investigated the interactions of mustard gas surrogates’ vapors on zinc and zirconium hydroxides and their composites with graphite oxide (GO) and/or Au or Ag nanoparticles. Even though a small quantity of reports about the detoxification of CWAs on metal oxides is reported in the literature, almost all of these studies are performed in the liquid phase. Both herein reported Zn(OH)₂ and Zr(OH)₄ showed a good adsorption performance, with the former being photoactive under visible …

One Ion To Rule Them All: Combined Antibacterial, Osteoinductive And Anticancer Properties Of Selenite-Incorporated Hydroxyapatite, Vuk Uskoković, Maheshwar Adiraj Iyer, Victoria M. Wu

Pharmacy Faculty Articles and Research

Although hydroxyapatite (HAp) has been doped with dozens of different ions, the quest for an ion imparting a combination of properties conducive to bone healing is still ongoing. Because of its protean potency and the similarity in size and shape to the phosphate tetrahedron, the selenite ion presents a natural ionic substitute in HAp. The incorporation of selenite into synthetic HAp using two different methods – co-precipitation and ion-exchange sorption – was studied for its effect on crystal properties and on a triad of biological responses: antibacterial, anticancer and osteoinductive. Co-precipitation yielded HAp with a higher selenite content than sorption …

Regenerative Electroless Etching Of Silicon, Kurt W. Kolasinski, Nathan J. Gimbar, Haibo Yu, Mark Aindow, Ermei Mäkilä, Jarno Salonen

Chemistry Faculty Publications

Regenerative electroless etching (ReEtching), described herein for the first time, is a method of producing nanostructured semiconductors in which an oxidant (Ox1) is used as a catalytic agent to facilitate the reaction between a semiconductor and a second oxidant (Ox2) that would be unreactive in the primary reaction. Ox2 is used to regenerate Ox1, which is capable of initiating etching by injecting holes into the semiconductor valence band. Therefore, the extent of reaction is controlled by the amount of Ox2 added, and the rate of reaction is controlled by the injection rate of Ox2. This general strategy is demonstrated specifically …

Reply To ‘On The Bonding In Ligand-Protected Gold Clusters’, Wen Wu Xu, Xiao Cheng Zeng, Yi Gao

Xiao Cheng Zeng Publications

In the recent Correspondence, Professor Henrik Grönbeck made several comments on the recently developed grand unified model (GUM), in particular using the ligand-protected gold cluster [Au₂₅(SR)₁₈]¹⁻ as an example. We noted that the latter cluster can be viewed as belonging to a special group of ligand-protected gold clusters that contain one or several icosahedral Au₁₃ motifs. For this group of clusters, a secondary block Au₁₃(8e) has been identified as a more convenient way to describe their structure anatomy and evolution. Another extension of the GUM is the identification of the new elementary …

Development Of Magnetorheological Elastomers (Mres) For Strength And Fatigue Resistance, J. Mcintyre, Stephen Jerrams

Books/Book Chapters

Natural rubber (NR)-based magnetorheological elastomers (MREs) exhibiting a reasonable switching effect were fabricated and tested. They were strong enough for use in automotive applications but still needed protection against ageing. Ethylene–propylene–diene rubber (EPDM) is a cost-effective material that is frequently used in the automotive industry because of its advantageous range of properties. With these applications in mind, it was a logical progression to the development of EPDM-based MREs. Unlike strain-crystallising NR, EPDM requires reinforcement to render its tensile and fatigue strength suitable for use in most applications. While small amounts of carbon black were sufficient for the NR-based MREs, a …

Probing The Structural Evolution Of Gold−Aluminum Bimetallic Clusters (Au2AlN−, N = 3−11) Using Photoelectron Spectroscopy And Theoretical Calculations, Navneet S. Khetrapal, Tian Jian, Gary V. Lopez, Seema Pande, Lai-Sheng Wang, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

We report a combined photoelectron spectroscopy and theoretical study of the structural evolution of aluminum cluster anions doped with two gold atoms, Au₂Al_n^– (n = 3−11). Well-resolved photoelectron spectra have been obtained at several photon energies and are used to compare with theoretical calculations to elucidate the structures of the bimetallic clusters. Global minima of the Au₂Al_n^– clusters were searched using the basin-hopping method combined with density functional theory calculations. Vertical detachment energies were computed for the low-lying isomers with the inclusion of spin−orbit effects and were used to generate simulated …

Asymmetric Membranes For High Capacity Lithium-Ion Battery Electrodes, Ian Byrd

College of Graduate Studies: Theses & Dissertations

Lithium-Ion Batteries (LIBs) have broad applications such as portable electronic devices, electric vehicles, and for green energy storage from intermittent sources. Current LIBs are limited by their low capacity materials at both the anode and cathode. At the anode, graphite suffers from a low capacity of only 372 mAh g^-1. The most commonly used cathode material is LiCoO₂ which has a meager capacity of 140 mAh g^-1. Thereby the broader applications of LIBs are limited due to these low capacities. It is imperative to develop higher capacity materials to further improve the performance of LIBs. …

Synthesis, Characterization, And Enhanced Magnetic Properties Of Iron Carbide Nanomaterials, Brent M. Williams

Theses and Dissertations

Permanent magnets are classified as hard magnetic materials with the main purpose of generating flux for applications such as electric motors, turbines, and hard drives. High coercivity, magnetic remanence, and saturation values with high stability are some of the requirements for permanent magnets. Rare-earth magnets including neodymium and samarium based magnets are known to have superior magnetic properties due to their high magnetocrystalline anisotropy. However, due to the price of rare-earth materials development of alternate permanent magnets composed of inexpensive materials is an ongoing process. Previously cobalt carbide (Co_xC) have shown promise as a potential rare-earth free magnet …

Choline Chloride Eutectics: Low Temperature Applications, Kaila M. Kuehn, Camille M. Massmann, Natalie R. Sovell

The Journal of Undergraduate Research

Deep eutectic solvents (DESs) have a lower melting point than each of their individual components due to ion dipole interactions or hydrogen bonding. Traditionally, DES are used for processing metals through plating and have many synthesis applications. DES are able to be substituted for hazardous solvents that are traditionally used for metal plating and synthesis. This, along with many other advantageous properties, appear promising for the use of DESs as solvents or for use in electrochemical systems, particularly at low temperatures. Choline chloride:propylene glycol was a novel DES synthesized and analyzed for its properties, including melting point, viscosity, conductivity, heat …

Nitric Oxide Release From Poly(Lactic-Co-Glycolic Acid) Nanoparticles And Titanium Alloy, Nina A. Reger

Electronic Theses and Dissertations

Current methods for the treatment of bacterial infection involve the use of systemic antibiotics, which are high concentrations of antibiotics delivered over a long period time. Unfortunately, the use of systemic antibiotics can cause harmful side effects to the patient and increases the possibility for antibiotic resistance. The delivery of antibiotics or alternative antimicrobial compounds, such as nitric oxide, directly to the site of infection would decrease the amount of antibiotic necessary to treat a bacterial infection.

Poly (lactic-co-glycolic acid)/polyvinyl alcohol nanoparticles and a titanium- aluminum-vanadium metal oxide alloy implant were surface functionalized to deliver nitric oxide. Polymer nanoparticles can …

Rationalizing The Band Gap Tunability Of Semiconductors Via Electronic Structure Calculations, Matthew N. Srnec

Electronic Theses and Dissertations

The polymorphs of titanium dioxide and various diamond-like semiconductor materials are promising candidates in photovoltaic solar cell applications. Several of these polymorphs have been studied with experimental and computational methods, which often aim at tuning the electronic structure, particularly the band gap value of the crystalline solid. Prior studies report that the addition of a substituent into the structure of titanium dioxide decreases its band gap value, but the reasons for this are unknown. Possible explanations for the change in band gap involve the substituent atom's crystal radius, electronegativity, and ionization energy. Understanding the cause of these changes will provide …

Synthesis Of Multifunctional Polyacrylates And A Binding Group To Hemoglobin For The Treatment Of Traumatic Brain Injuries, Marina Michaud

Honors College Theses

Hemoglobin based oxygen carriers (HBOCs) hold promise as an effective emergency treatment of severe traumatic brain injuries (TBI). In the latest generation of HBOCs, polynitroxyl-pegylated hemoglobin (PNPH), cell-free hemoglobin is modified with TEMPO and PEG which reduce the toxicities associated with earlier generations of HBOCs. In our efforts to optimize the economic and therapeutic impacts of PNPH’s we have synthesized polydimethylaminoethyl methacrylate (poly-DMAEMA) under controlled living conditions via reverse addition-fragmentation chain transfer (RAFT) polymerization. The poly-DMAEMA was then successfully functionalized via quaternization of its NMe₂ groups using chloroacetate derivatives of the TEMPO and PEG. This process was quantitative and …

Charge Transfer At The Liquid/Solid Interface To Affect Nanostructure Formation, Kurt W. Kolasinski

Chemistry Faculty Publications

No abstract provided.

Development Of Diverse Size And Shape Rna Nanoparticles And Investigation Of Their Physicochemical Properties For Optimized Drug Delivery, Daniel L. Jasinski

Theses and Dissertations--Pharmacy

RNA nanotechnology is an emerging field that holds great promise for advancing drug delivery and materials science. Recently, RNA nanoparticles have seen increased use as an in vivo delivery system. RNA was once thought to have little potential for in vivo use due to biological and thermodynamic stability issues. However, these issues have been solved by: (1) Finding of a thermodynamically stable three-way junction (3WJ) motif; (2) Chemical modifications to RNA confer enzymatic stability in vivo; and (3) the finding that RNA nanoparticles exhibit low immunogenicity in vivo.

In vivo biodistribution and pharmacokinetics are affected by the physicochemical …

Investigation Of Host-Sensitized Luminescence Of Trivalent Lanthanide Doped Yttrium Phosphate Using Vuv Spectroscopy, Zachary Way

All Master's Theses

Host-sensitized luminescence of yttrium phosphate doped with trivalent lanthanide elements prepared via two synthetic approaches was studied using VUV spectroscopy. A correlation between an unusually intense 150 nm excitation intensity and the ground state energy level of select trivalent lanthanide elements was proposed. Using spectroscopy, the host-to-activator transfer efficiencies of YPO₄:Ln³⁺ (Ln³⁺ = Sm³⁺, Eu³⁺ and Tb³⁺) were evaluated for two synthetic approaches. Electron-hole pair trapping efficiencies and S_loss values were calculated using published kinetic models.

A Fast Linear Electro-Optical Effect In A Non-Chiral Bent-Core Liquid Crystal, Yuri Panarin, S.P. Sreenilayam, J.K. Vij, A. Lehmann, C. Tschierske

Articles

We report the observation of an electro-optical effect for a linear rotation of the optical axis as function of the electric field in an achiral tilted bent-core liquid crystalline compound, in which 4-cyanoresorcinol bisbenzoate core is symmetrically terminated by long linear alkyl chains (n =16) on both ends. The linear electro-optic effect observed in this material is similar to the deformed helical ferroelectric liquid crystal (DHFLC) effect reported previously in a FLC material except that dimensions of the helical pitch differ by two orders of magnitude. In the chiral systems, the helical pitch usually lies on the scale of sub-optical …

Efficient Integration Of Plasmonic And Excitonic Properties Of Metal And Semiconductor Nanostructures Via Sol-Gel Assembly, Dilhara Liyanage

Theses and Dissertations

Research in nanoscience has gained noteworthy interest over the past three decades. As novel chemical and physical properties that are vastly different from extended solids are realized in nanosized materials, nanotechnology has become the center of attention for material in research community. Much to our amazement, investigations in the past two decades revealed that the nanocrystalline semiconductors are “THE PRIME CANDIDATES” to meet the growing energy demand, sensor development, cellular imaging and a number of other optoelectronic applications. Nonetheless, synthesis of nanostructures with control over physical parameters is not sufficient, yet assembling them into functional nanoarchitectures with unique and tunable …

Criegee Intermediate-Hydrogen Sulfide Chemistry At The Air/Water Interface, Manoj Kumar, Jie Zhong, Joseph S. Francisco, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

We carry out Born–Oppenheimer molecular dynamic simulations to show that the reaction between the smallest Criegee intermediate, CH₂OO, and hydrogen sulfide (H₂S) at the air/water interface can be observed within few picoseconds. The reaction follows both concerted and stepwise mechanisms with former being the dominant reaction pathway. The concerted reaction proceeds with or without the involvement of one or two nearby water molecules. An important implication of the simulation results is that the Criegee-H₂S reaction can provide a novel non-photochemical pathway for the formation of a C–S linkage in clouds and could be a …

Α-Eleostearic Acid Extraction By Saponification Of Tung Oil And Its Subsequent Polymerization, Amanda Murawski

College of Graduate Studies: Theses & Dissertations

The goal of environmentally sound research is to provide alternatives that are more sustainable and renewable, such as vegetable oil-based polymers, than the current petroleum-based products. Vegetable oil-based polymers have received a lot of attention recently due their multifaceted properties, which are simply achieved by adjusting the monomer or resin composition. The carbon-carbon double bonds in unsaturated oils are ideal reactive sites for the free radical or cationic polymerizations. Most vegetable oils must be modified before polymerization due to the low reactivity of their non-conjugated fatty acid chains. Tung oil (TO) contains ~83% of a triply conjugated fatty acid ( …

Exploring The Effects Of Different Classroom Environments On The Learning Process. Synthesis Of Thiazole-Linked Porous Organic Polymers For Co2 Separation And Nitro-Aromatics Sensing., Davide D'Urbino

Theses and Dissertations

When attempting to study the learning process of undergraduate chemistry student, the classroom and any interaction that take place within it constitute the social context of interest. By studying how different approaches can foster different classroom environments, it is possible to approach course design from an informed and scientifically sound perspective. Thus, it becomes necessary to identify and quantify the factors that have a positive or negative effect on the classroom environment. Social comparison concerns, comfort levels and self-efficacy have been shown to be social factors that affect each other as well as the learning process and have therefore been …

Investigations Into Structure And Properties Of Atomically-Precise Transition Metal-Chalcogenide Clusters Of Crte And Ligated Cr6te8(Pet3)6, Anthony F. Pedicini

Theses and Dissertations

The complete understanding of a clusters electronic structure, the primary mechanisms for its properties and stabilization is necessary in order to functionalize them for use as building blocks within novel materials. First principle theoretical studies have been carried out upon the electronic properties of Cr_xTe_y (x = 1 – 6, y = 0 – 8, x + y ≤ 14), as well as for the larger triethylphosphine (PEt₃) ligated cluster system of Cr₆Te₈(PEt₃)₆. Together, we aim to use the information garnered from the smaller clusters to address …