Chemistry Commons^™

Evaluation Of Functionalized Magnetite Nanoparticles For The Removal Of Heavy Metal Ions From Aqueous Media, Khaula A. Ai Jahoushi

Theses

Sorption is one of the most efficient techniques for the removal of heavy metal ions from waste water. It involves the use of solid materials, known as sorbents, which can be natural of synthetic in origin. Recently, synthetic nanomaterials of various compositions have been used as sorbents. Among these materials, calcium phosphate; also known as hydroxyapatite (HAp), and magnetite were previously investigated as potential sorbents. In the current study, commercial HAp, and magnetite nanoparticles as well as their physical and chemical mixtures were investigated as potential sorbents for the removal of Cd²⁺ ions from simulated wastewater. A comparison is made …

Comparative Degradation Of Emerging Pollutants Using Chemical And Enzymatic Approaches, Khadega Abobaker Al-Maqdi

Theses

Organic pollutants, especially those found in water bodies; pose a direct threat to various aquatic organisms as well as humans. A variety of different remediation approaches, including chemical and biological methods have been developed for the degradation of these organic pollutants. However, comparative mechanistic studies of pollutant degradation by these different systems are almost non-existent. In this study, the degradation of two emerging pollutants an antibiotic pollutant, Sulfamethoxazole (SMX) and a model thiazole pollutant, Thioflavin T (ThT), was carried out using advanced oxidation process (AOP), using UV+H2O2 or a peroxidase enzyme system. Optimization conditions for Sulfamethoxazole degradation by peroxidase enzyme …

Air-Oxidation Of Phenolic Resin Aerogels: Backbone Reorganization, Formation Of Ring-Fused Pyrylium Cations, And The Effect On Microporous Carbons With Enhanced Surface Areas, Hojat Majedi Far, Suraj Donthula, Tahereh Taghvaee, Adnan Malik Saeed, Zachary Garr, Chariklia Sotiriou-Leventis, Nicholas Leventis

Chemistry Faculty Research & Creative Works

This paper is a thorough investigation of the chemical transformations during pyrolytic conversion of phenolic resins to carbons, and reports that all carbons obtained from main-stream phenolic resins including phloroglucinol-formaldehyde (FPOL), phloroglucinol-terephthalaldehyde (TPOL), resorcinol-formaldehyde (RF), and phenol-formaldehyde (PF) contain fused pyrylium rings and charge-compensating phenoxides. Those four phenolic resins were prepared via a fast HCl-catalyzed process as low-density nanostructured solids classified as aerogels, which, owing to their open porosity, allowed air circulation through their bulk. In that regard, the first step of this study was the air-oxidation of those phenolic resin aerogels at 240 °C. In FPOL and TPOL aerogels, …

Catalytic Reduction Of Bisulfite By Myoglobin/Surfactant Films, Radalla Abdellatty, Md. Hafizur Rahman, Michael D. Ryan

Chemistry Faculty Research and Publications

The voltammetry of bisulfite at a film formed with myoglobin was studied in aqueous solutions. A broad wave was observed for the reduction of bisulfite. Using controlled potential electrolysis, the reduction at potentials positive of the Fe^II/Fe^Iwave formed dithionite exclusively. As the potential approached the region for the Fe^II/Fe^I reduction, bisulfite was reduced primarily to HS⁻. Even at the negative potentials, some dithionite was still formed, which could then be electrochemically reduced to thiosulfate. Analysis of the formation of HS⁻, dithionite and thiosulfate during the electrolysis was consistent with …

Single-Reference Coupled Cluster Theory For Multi-Reference Problems, Johannes T. Margraf, Ajith Perera, Jesse J. Lutz, Rodney J. Bartlett

Faculty Publications

Coupled cluster (CC) theory is widely accepted as the most accurate and generally applicable approach in quantum chemistry. CC calculations are usually performed with single Slater-determinant references, e.g., canonical Hartree-Fock (HF) wavefunctions, though any single determinant can be used. This is an attractive feature because typical CC calculations are straightforward to apply, as there is no potentially ambiguous user input required. On the other hand, there can be concern that CC approximations give unreliable results when the reference determinant provides a poor description of the system of interest, i.e., when the HF or any other single determinant ground state has …

Comparison Of Various Means Of Evaluating Molecular Electrostatic Potentials For Noncovalent Interactions, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

The various heterodimers formed by a series of Lewis acids with NH3 as Lewis base are identified. Lewis acids include those that can form chalcogen (HSF and HSBr), pnicogen (H2PF and H2PBr), and tetrel (H3SiF and H3SiBr) bonds, as well as H‐bonds and halogen bonds. The molecular electrostatic potential (MEP) of each Lewis acid is considered in a number of ways. Pictorial versions show broad regions of positive and negative MEP, on surfaces that vary with respect to either the value of the chosen isopotential, or their distance from the nuclei. Specific points are identified where the MEP reaches a …

Superconductivity At Т≈200 K In Bismuth Cuprates Synthesized Using Solar Energy, J. Chigvinadze, Juana Acrivos, S. Ashimov, D. Gulamova, G. Donadze

Faculty Publications, Chemistry

When investigating low-frequency (0.1 Hz) oscillations of multiphase high-temperature cuprate superconductors (HTCS) Bi1,7Pb0,3Sr2Ca(n-1)CunOy (n=2-30), a wide attenuation peak (ΔT~100 К) with a maximum at Т≈200 К was detected. This peak was particularly pronounced in field cooling (FC) experiments, i.e. after abrupt cooling of the sample in the external magnetic field at the temperature Т<Тс with subsequent slow warming up to room temperature with invariance of the applied field. The attenuation peak height depended on the preliminaryorientation (before cooling) of the samples θ in the measured permanent magnetic field Н. On the one hand, it is well known that, after the FC procedure and subsequent slow warming up, at the temperatures close to the critical temperature Тс, the attenuation peak associated with “melting” of the Abrikosov frozen vortex structure and its disappearance at Т >Тс is detected in monophase samples. At the same time, in most multiphase bismuth HTCS samples, synthesized using solar energy and superfast quenching of the melt, the attenuation peak with the maximum at Т≈200 К was observed.Depending on the conditions of synthesis, the attenuation peak could …

Special Issue On Supercapacitors, Xiao-Gang Zhang

Journal of Electrochemistry

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Electrochemical Capacitors Based On Anion-Graphite Intercalation Compounds, Hong-Yu Wang, Hui Fan, Xiao-Hong Wang, Li Qi

Journal of Electrochemistry

Anions can be electrochemically intercalated into a graphite electrode with a reversible capacity as high as 120 mAh·g^-1 at the high potential near 5 V vs. Li/Li⁺. Besides, graphite is environmentally benign, economic and abundant in China. Therefore, graphite is a very promising positive electrode material for asymmetric capacitors using non-aqueous electrolytes. However, the performance of graphite positive electrode is quite sensitive to various affecting factors, such as the compositions of electrolyte solutions, graphite type and ambient temperature, and so on. In the platform of activated carbon/graphite capacitors, the electrochemical behavior of anion-graphite intercalation compounds can be …

Strategies To Enhance Energy Density For Supercapacitors, Jun-Wei Lang, Xu Zhang, Ru-Tao Wang, Xing-Bin Yan

Journal of Electrochemistry

The biggest advantage of supercapacitor lies in not only the excellent pulse and fast charging-discharging performance, but also the characteristics of long cycle life and wide operating temperature window with no pollution. However, the energy density of supercapacitor is low. In this paper, the working principle, the development status, defects and improvement method of supercapacitors are introduced. Based on the research workes of the supercapacitors with high energy density in our group, combined with the literature reports in recent years, the strategies to promote the energy density of supercarpacitors will be focused. The strategies for the enhancement of energy density …

Attempts To Improve The Energy Capacity Of Capacitive Electrochemical Energy Storage Devices, Lin-Po Yu, George Z. Chen

Journal of Electrochemistry

This article reviews selected literatures from the authors’ research group on the development of capacitive electrochemical energy storage (EES) devices, focusing on supercapacitors and supercapatteries at both the electrode material level and device level. Electronically conducting polymers (ECPs) and transition metal oxides (TMOs) composited with carbon nanotubes (CNTs) were found to be able to improve the capacitance performance as capacitive faradaic storage electrode. Carbon materials, like activated carbon (Act-C) and carbon black, were used to fabricate non-faradaic capacitive storage electrode. It was found that the electrode capacitance balance can effectively extend the maximum charging voltage (MCV) of the supercapacitor, and …

Porous Carbon Materials Produced By Koh Activation For Supercapacitor Electrodes, Jiang-Lin Ye, Yan-Wu Zhu

Journal of Electrochemistry

Porous carbon materials with high specific surface area and excellent conductivity have wide applications in supercapacitor electrodes. Much effort has been made to synthesize and tailor the microstructures of porous carbon materials via various activation procedures (physical and chemical activations). In particular, the chemical activation using potassium hydroxide (KOH) as an activating reagent is promising because of the well-defined micropore size distribution and ultrahigh specific surface area up to 3000 m²·g^-1 of the resulting porous carbons. Based mainly on the previous works taken by the authors and collaborators in the field, we have summarized the activation mechanism …

Recent Advances On Carbon And Transition Metallic Compound Electrodes For High-Performance Supercapacitors, Dun Lin, Xi-Yue Zhang, Yin-Xiang Zeng, Ming-Hao Yu, Xi-Hong Lu, Ye-Xiang Tong

Journal of Electrochemistry

Supercapacitors (SCs) have stimulated intensive interests for their promising applications in electric vehicles and portable electronics, etc. Electrode material is the most important key component of SCs, which vastly determines the performance of SCs. Carbon and transition metallic compound materials have attracted considerable attention and been widely explored as electrode materials. However, the insufficient capacitance of carbon materials and unsatisfactory conductivity and cyclic stability of transition metallic compounds severely limit their implementation as robust SC electrodes. Herein, we highlight our recent efforts to boost the capacitive performance of carbon and metal oxide/nitride electrodes by rationally structural and componential design. The …

Lithium Ion Hybrid Capacitor With High Energy Density, Xian-Zhong Sun, Xiong Zhang, Kai Wang, Yan-Wei Ma

Journal of Electrochemistry

Lithium ion hybrid capacitors are electrochemical energy storage devices combining the advantages of both Li-ion battery and electrochemical capacitor. They can be extensively used in many fields. However, the commercialization of lithium ion hybrid capacitor has been encountered several problems, e.g., the device structure design, the screening of materials, the pre-lithiation process, and the interface between electrolyte and electrode, etc. This review summarizes the recent research advances in lithium ion hybrid capacitor with high energy density, including the selection of the active materials in cathode/anode and the separator, the pre-lithiation method using the three-electrode structure, the high- and low-temperature performances, …

Template Induced Fabrication Of Nitrogen Doped Carbon Sheets As Electrode Materials In Supercapacitors, Tao Huang, Guang-Zhi Tao, Chong-Qing Yang, Deng Lu, Lie Ma, Dong-Qing Wu

Journal of Electrochemistry

Due to the good electrical conductivity, high specific surface area, and excellent chemical/mechanical stability, carbon nanomaterials with two-dimensional morphology have gradually become the hot topic of the research on supercapacitors. Herein, we report for the first time the fabrication of nitrogen doped carbon sheets (NCSs). In our approach, the sheet-like magnisum aluminum (MgAl) layered double hydroxide was used as the hard template, which was mixed with o-phenylene diamine and iron chloride. The following thermal treatment could render the polymerization and carbonization of o-phenylene diamine. The NCSs with ordered hexagonal architectures were formed by final etching process of the thermally treated …

Preparation And Characterization Of Cellulose Acetate-Based Separator For Lithium-Ion Batteries, Hua-Feng Luo, Yuan-Dong Qiao

Journal of Electrochemistry

To improve the electrolyte wettability and thermal resistance of separators used for lithium-ion battery, a novel cellulose acetate (CA)-based separator is facilely prepared by non-solvent induced phase separation (NIPS) wet-process and investigated in lithium-ion batteries. Systematical investigations including morphological characterization, electrolyte wettability and thermal resistance testing were carried out. The results demonstrated that the CA-based separator exhibited well developed three-dimensional porous structures with porosity up to 65%, which is 1.5 times higher than that of PE separator. The CA separator also showed excellent electrolyte uptake (285%) and thermal stability at 150 ^oC for 30 min. Compared with the commercial …

An Aqueous Zn-Ion Capacitor, Jing-Wen Zhao, Jia-Jia Li, Peng-Xian Han, Guang-Lei Cui

Journal of Electrochemistry

We first present a new aqueous zinc-ion (Zn-ion) capacitor based on vanadium pentoxide (V₂O₅) cathode, activated carbon (AC) anode, and 2 mol·L^-1 zinc trifluoromethanesulfonate (Zn(TfO)₂) electrolyte. The Zn-ion capacitor possesses a wide electrochemical window of 1.4 V, good rate capability and cycling stability. The XRD data demonstrates that the Zn²⁺ ion serving as the charge carrier could be reversibly intercalated into the V₂O₅. This capacitor delivered a power density of 181 W·kg^-1 and an energy density of 4.5 Wh·kg^-1 at 1000 mA·g^-1. This work …

New Synthetic Reactions Towards Global Chlorination And Enamides Functionalization, Mirza Ardella Saputra

LSU Doctoral Dissertations

This dissertation focuses on two main projects, global chlorination and enamide functionalization, which both encompass in cationic intermediates. Inspired by the desires to find a new chlorination method, global chlorination project is emphasized in chapter one and chapter two, in which chapter one details various known chlorine-containing natural products, including alkyl chlorides and vinyl chlorides. This chapter also describes the previously known protocols to synthesize alkyl chlorides in the attempts of chlorosulfolipids total syntheses, as well as several known reactions to synthesize vinyl chlorides that are both important functional groups in organic synthesis. Chapter two depicts our novel synthetic reaction …

Synthesis, Crystal Structure, And Photoluminescent Properties Of 3,3′,4,4′-Tetraethyl-5,5′-Divinyl-2,2′-Bipyrrole Derivatives, Toru Okawara, Reo Kawano, Hiroya Morita, Alan Finkelstein, Renjiro Toyofuku, Kanako Matsumoto, Kenji Takehara, Toshihiko Nagamura, Seiji Iwasa, Sanjai Kumar

Publications and Research

Photoluminescent divinylbipyrroles were synthesized from 3,3′,4,4′-tetraetyl-2,2′-bipyrrole-5,5′-dicarboxaldehyde and activated methylene compounds via aldol condensation.For mechanistic clarity, molecular structures of Meldrum’s acid- and 1,3-dimethylbarbituricacid-derived divinylbipyrroles were determined by single-crystal X-ray diffraction. Photoluminescentproperties of the synthesized divinylbipyrroles in dichloromethane were found to be dependent onthe presence of electron withdrawing groups at the vinylic terminal. The divinylbipyrroles derivedfrom malononitrile, Meldrum’s acid, and 1,3-dimethylbarbituric acid showed fluorescent peaks at553, 576, and 602 nm respectively. Computational studies indicated that the alkyl substituents on thebipyrrole 3 and 3′positions increased energy level of the highest occupied molecular orbital (HOMO)compared to the unsubstituted derivatives and provided rationale for the …

Organelle-Specific Single-Molecule Imaging Of Α4Β2 Nicotinic Receptors Reveals The Effect Of Nicotine On Receptor Assembly And Cell-Surface Trafficking, Ashley M. Fox-Lee, Faruk H. Moonschi, Christopher I. Richards

Chemistry Faculty Publications

Nicotinic acetylcholine receptors (nAChRs) assemble in the endoplasmic reticulum (ER) and traffic to the cell surface as pentamers composed of α and β subunits. Many nAChR subtypes can assemble with varying subunit ratios, giving rise to multiple stoichiometries exhibiting different subcellular localization and functional properties. In addition to the endogenous neurotransmitter acetylcholine, nicotine also binds and activates nAChRs and influences their trafficking and expression on the cell surface. Currently, no available technique can specifically elucidate the stoichiometry of nAChRs in the ER versus those in the plasma membrane. Here, we report a method involving single-molecule fluorescence measurements to determine the …

High-Statistics Β+/Ec-Decay Study Of 122Xe, B. Jigmeddorj, P. E. Garrett, C. A. Andreoiu, G. C. Ball, T. Bruhn, D. S. Cross, A. B. Garnsworthy, B. Hadinia, M. Moukaddam, J. Park, J. L. Pore, A. J. Radich, M. M. Rajabali, E. T. Rand, U. Rizwan, C. E. Svensson, P. Voss, Z. Wang, J. L. Wood, Steven W. Yates

Chemistry Faculty Publications

Low-lying excited states of ¹²²Xe have been studied via the β⁺/EC decay of ¹²²Cs with the 8π γ-ray spectrometer at the TRIUMF Isotope Separator and Accelerator facility. The data collected have enabled the observation of new in-band transitions in the excited 0⁺ state bands. In addition, the 2⁺ members of the second 0⁺ and third 0⁺ state bands have been firmly confirmed by angular correlation analysis.

Responsive Nanogel Probe For Ratiometric Fluorescent Sensing Of Ph And Strain In Hydrogels, Mingning Zhu, Dongdong Lu, Shanglin Wu, Qing Lian, Wenkai Wang, Amir H. Milani, Zhengxing Cui, Nam T. Nguyen, Mu Chen, L. Andrew Lyon, Daman J. Adlam, Anthony J. Freemont, Judith A. Hoyland, Brian R. Saunders

Engineering Faculty Articles and Research

In this study a new pH-responsive nanogel probe containing a complementary nonradiative resonance energy transfer (NRET) fluorophore pair is investigated and its ability to act as a versatile probe of network-related changes in three hydrogels demonstrated. Fluorescent sensing using NRET is a powerful method for studying relationships between Angstrom length-scale structure and macroscopic properties of soft matter. Unfortunately, inclusion of NRET fluorophores into such materials requires material-specific chemistry. Here, low concentrations of preformed nanogel probes were included into hydrogel hosts. Ratiometric photoluminescence (PL) data for the gels labeled with the nanogel probes enabled pH-triggered swelling and deswelling to be studied …

Can Hcch/Hbnh Break B=N/C=C Bonds Of Single-Wall Bn/Carbon Nanotubes At Their Surface?, Tapas Kar, Peter Grüninger, Steve Scheiner, Holger F. Bettinger, Ajit K. Roy

Chemistry and Biochemistry Faculty Publications

The iminoborane (HBNH) molecule, which prefers cycloaddition reactions, selectively breaks a B=N bond of smaller diameter single-wall BNNTs and expands a ring at their surface, either at the edges or at the middle of the tube. Density functional theory (DFT) is used to test whether its organic counterpart HCCH can do the same with BNNTs. HCCH-BNNT complexes are identified and transition states located for these combination reactions. Also explored are possible reactions of HBNH with SWNTs and HCCH with SWNTs. Data suggest that B=N (C=C) bond breaking, followed by ring expansion at the surface may be possible. Although [2+2] cycloaddition …

Newest Kid On The Block: Characterization Of The Novel Multidrugresistant Pathogen, Candida Auris, Lindsey Masone, Susanna Mirabelli

Discovery Day (formerly Post & Beyond)

Candida auris is a novel and emerging fungal pathogen capable of causinginvasive, and often fatal, bloodstream and wound infections in immunocompromised patients. Several outbreaks have been reported in hospitals across the world, including the United States, and predominantly in New York. C.auris exhibits extensive multidrug resistance that has never been seen in any Candida species, and is often misdiagnosed for other Candida species, thus limiting treatment options for patients. Our laboratory obtained 10 C. auris isolates in order to perform in vitro antifungal susceptibility testing and determine the Minimum Inhibitory Concentration (MIC) under Clinical and Laboratory Standards Institute guidelines. …

Unmanned Aerial Systems For Monitoring Trace Tropospheric Gases, Travis J. Schuyler, Marcelo I. Guzman

Chemistry Faculty Publications

The emission of greenhouse gases (GHGs) has changed the composition of the atmosphere during the Anthropocene. Accurately documenting the sources and magnitude of GHGs emission is an important undertaking for discriminating the contributions of different processes to radiative forcing. Currently there is no mobile platform that is able to quantify trace gases at altitudes(UASs) can be deployed on-site in minutes and can support the payloads necessary to quantify trace gases. Therefore, current efforts combine the use of UASs available on the civilian market with inexpensively designed analytical systems for monitoring atmospheric trace gases. In this context, this perspective introduces the …

Formation Of Carbon-Carbon And Carbon-Hetero Bonds Through Gold Catalysis, Boliang Dong

USF Tampa Graduate Theses and Dissertations

This dissertation mainly contains two parts: one is C-X (C, O, S) bond formation through gold(I) catalysis, one is new applications via gold(I/III) redox catalysis.

In first part, gold(I) catalysts would be introduced and their general applications, then the TA-Au species will be emphasized including the design, synthesis, characters and their application in catalysis. The applications are well developed during the past decade in our group, but here only involves three examples regarding C-C, C-O and C-S bond formations. From these effective applications, the unique stability and reactivity of TA-Au will be studied and explained, which is the reason and …

Spectroscopic And Computational Studies Of Reversible O2 Binding By A Cobalt Complex Of Relevance To Cysteine Dioxygenase, Anne A. Fischer, Sergey V. Lindeman, Adam T. Fiedler

Chemistry Faculty Research and Publications

The substitution of non-native metal ions into metalloenzyme active sites is a common strategy for gaining insights into enzymatic structure and function. For some nonheme iron dioxygenases, replacement of the Fe(II) center with a redox-active, divalent transition metal (e.g., Mn, Co, Ni, Cu) gives rise to an enzyme with equal or greater activity than the wild-type enzyme. In this manuscript, we apply this metal-substitution approach to synthetic models of the enzyme cysteine dioxygenase (CDO). CDO is a nonheme iron dioxygenase that initiates the catabolism of L-cysteine by converting this amino acid to the corresponding sulfinic acid. Two mononuclear …

Kinetic Characterization Of Listeria Monocytogenes 2-C- Methyl-D-Erythritol 4-Phosphate Cytidylyltransferase ( Cms ) Enzymes Using High Performance Liquid Chromatography ( Hplc ), Mark Oblazny

Theses and Dissertations

Infectious diseases, with increasing prevalence of antibiotic resistant bacteria, coupled with the declining rate in discovery of antimicrobial agents, impose one of the most significant threats to human health. Here we identify 2-C-methyl-D-erythritol 4-phosphate cytidylyltransferase (CMS) as a valid target for antibiotic development which is an enzyme in pathogenic organisms that leads to the biosynthesis of isoprene precursor molecules. Isoprene molecules are one of nature’s most common building blocks that are vital to many biological metabolic processes and are synthesized via the mevalonic acid dependent (MVA), or methylerythritol phosphate (MEP) pathway. Vertebrates utilize the MVA pathway, while many pathogenic bacteria …

The Biochemical Assessment Of Two Secreted Acid Phosphatases From Leishmania Tarentolae, Their Response To Electric Fields, Glycosidase Incubation, And / Or Vanadium, Benjamin M. Dorsey

Theses and Dissertations

Leishmaniasis, as defined by the Center for Disease Control and Prevention, is a neglected tropical disease with 1.6 million new cases reported each year. However, there is yet to be safe, effective, and affordable treatments provided to those affected by this disease1. Still underappreciated as a potential pharmaceutical targets, especially for cutaneous leishmaniasis infections, are the two isozymes of secreted acid phosphatase (SAP); secreted acid phosphatase 1 (SAP1) and secreted acid phosphatase 2 (SAP2). These enzymes are involved in the survival of the parasite in the sand fly vector, and the prevention of host macrophages from forming parasitophorous vacuole and …

Spectroscopic And Computational Characterization Of Lanthanum-Mediated C-H And N-H Bond Activation Of Amines, Silver Nyambo, Yuchen Zhang, Dong-Sheng Yang

Commonwealth Computational Summit

Metal-mediated bond activation of small organic and inorganic molecules plays critical roles in chemical transformation of small molecules into value-added products.

This is because few of such chemical reactions would occur under mild conditions without the metal activation.

In this work, lanthanum atom reactions with alkylamines are carried out in a laser-ablation supersonic molecular beam source; C-H and N-H bond activation in these species is investigated.

The reaction products are observed with photoionization time-of-flight mass spectrometry and characterized by mass-analyzed threshold ionization (MATI) spectroscopy and theoretical calculations.

Adiabatic ionization energy and metal-ligand and ligand-based vibrational frequencies of several short-lived lanthanum …