Chemistry Commons^™

Preparations And Electrochemical Properties Of Bc/Coni2S4@Ppy Flexible Composites For Supercapacitors, Si-Yuan Peng, Shi-Run Yang, Jing-Hong Zhou, Zhi-Jun Sui, Tao Zhang, Yi Shi, Xing-Gui Zhou

Journal of Electrochemistry

Flexible supercapacitor is one of the most promising energy storage devices for portable and wearable electronic products due to its advantages of high power density, fast charging and long cycle life. Therefore, self-supporting flexible electrode materials with high performance have attained more and more attention both in academia and in industry recently. In this work, using bacterial cellulose (BC) as a flexible substrate, the bacterial cellulose/nickel-cobalt sulfide@polypyrrole (BC/CoNi₂S₄@PPy) flexible composites with three-dimensional porous network and good conductivity were prepared by a combined solvothermal-in-situ polymerization-vacuum filtration method. The samples were characterized by X-ray diffraction, …

Syntheses Of Na3V2(Po4)2O2F As A Cathode For Sodium Ion Battery Application, Kai Wu

Journal of Electrochemistry

High-temperature solid-state method, hydro-thermal method and solvo-thermal method have been mainly employed to synthesize Na₃V₂(PO₄)₂O₂F (NVPF) cathode materials. However, these methods are energy consuming and complicated, which is not applicable for a large scale industrial production. In this study, a rather low-temperature (70℃) co-precipitation strategy was proposed to synthesize NVPF cathode materials. The as-prepared NVPF cathode materials showed a spherical shape with a diameter of 400 ~ 500 nm, and exhibited a sodium storage of 105.6 mAh·g^-1 and an efficiency of 90.06%. After a simple thermal process, the specific …

Research Progress On Transition State Of Organic Electrode Materials, Xue-Qian Zhang, Zhou-Guang Lu, Wei-Wei Huang

Journal of Electrochemistry

With the increasing requirements for high energy density, long lifetime, high safety, environmentally friendly fabrication, and sustainable development of large energy storage devices, the society calls for new electrode materials in rechargeable batteries beyond traditional inorganic materials which are limited by specific capacity. Organic electrode materials have been widely used in rechargeable batteries due to their advantages of large theoretical capacity, designable structures and environmentally friendly fabrications. In this review, the radical intermediates of organic electrode materials produced in the charging-discharging process (redox reaction) and their types are systematically reviewed. The stability of radical intermediates controlled by changing the structure …

Multifunctional Conductive Paths Obtained By Laser Processing Of Non-Conductive Carbon Nanotube/Polypropylene Composites, Federico Cesano, Mohammed Jasim Uddin, Alessandro Damin, Domenica Scarano

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Functional materials are promising candidates for application in structural health monitoring/self-healing composites, wearable systems (smart textiles), robotics, and next-generation electronics. Any improvement in these topics would be of great relevance to industry, environment, and global needs for energy sustainability. Taking into consideration all these aspects, low-cost fabrication of electrical functionalities on the outer surface of carbon-nanotube/polypropylene composites is presented in this paper. Electrical-responsive regions and conductive tracks, made of an accumulation layer of carbon nanotubes without the use of metals, have been obtained by the laser irradiation process, leading to confined polymer melting/vaporization with consequent local increase of the nanotube …

Research Progress Of Sio2 Regrowth During Selective Etching Process In 3d Nand Manufacture Procedure, Zi-Han Zhou, Yun-Wen Wu, Ming Li, Su Wang

Journal of Electrochemistry

As one of the most significant memory chips in semiconductor market, NAND has been developed from two-dimension (2D) to three-dimension (3D). Due to the three-dimensional memory structure of 3D NAND, the capacity density, read-write speed and reliability of memory chips have been greatly improved, as well as the reduction of power dissipation. It is by nitride-oxide selective etching process in the alternate stacked structure of 3D NAND that the inter-dielectric layers can be obtained. The more stack layers, the better performance of chips will be. Meanwhile, however, silicon dioxide (SiO₂) would regrow on the corner of oxide layers, …

Study On Li3Bo3 Interface Modification Of Garnet Solid Electrolyte, Gui-Wei Chen, Zheng-Liang Gong

Journal of Electrochemistry

Garnet solid-state electrolytes have become the research hotspot due to their high ionic conductivity, wide electrochemical stability window and good air stability. However, there are still a series of problems to be solved. The poor contact between the lithium (Li) metal and garnet pellet make it difficult to build stable ion diffusion channels, resulting in large interfacial resistance. The continuous growth of lithium dendrites can penetrate the electrolyte pellet and cause a short circuit in the solid-state battery. Herein, a novel strategy is proposed to improve the wettability of LLZTO electrolyte with Li metal, via interfacial modification of LLZTO electrolyte …

Perspective On Multi-Scale Simulation Of Thermal Transport In Solids And Interfaces (Vol 23, Pg 1785, 2021), Ming Hu, Zhonghua Yang

Faculty Publications

Correction for ‘Perspective on multi-scale simulation of thermal transport in solids and interfaces’ by Ming Hu et al., Phys. Chem. Chem. Phys., 2021, 23, 1785–1801, DOI: 10.1039/D0CP03372C.

Role Of Molecular Structure On Modulating The Interfacial Dynamics For Shallow Trench Isolation (Sti) Chemical Mechanical Planarization (Cmp) Applications, Katherine M. Wortman-Otto, Abigail N. Linhart, Abigail L. Dudek, Brian M. Sherry, Jason J. Keleher

Chemistry Department Faculty Articles

As feature sizes continue to shrink well beyond the 7 nm node, understanding the delicate balance present in the chemical mechanical planarization (CMP) process is of utmost importance. In order to achieve high through-put and defect-free CMP processes it is critical to develop predictive analytical techniques that directly correlate to macroscopic STI CMP performance metrics (i.e. oxide/nitride removal, defectivity, and dishing/erosion). This work employed a suite of techniques to monitor the CeO2 nanoparticle interfacial redox processes in the presence of structurally diverse rate modulating additives. Specifically, utilizing a UV–vis spectroscopic technique, the Ce3+/Ce4+ ratio in the presence of different slurry …

Computationally-Efficient Spatiotemporal Correlation Analysis Super-Resolves Anomalous Diffusion, Shawn Yoshida, William Schmid, Nam Vo, William Calabrase, Lydia Kisley

Faculty Scholarship

Anomalous diffusion dynamics in confined nanoenvironments govern the macroscale properties and interactions of many biophysical and material systems. Currently, it is difficult to quantitatively link the nanoscale structure of porous media to anomalous diffusion within them. Fluorescence correlation spectroscopy super-resolution optical fluctuation imaging (fcsSOFI) has been shown to extract nanoscale structure and Brownian diffusion dynamics within gels, liquid crystals, and polymers, but has limitations which hinder its wider application to more diverse, biophysically-relevant datasets. Here, we parallelize the least-squares curve fitting step on a GPU improving computation times by up to a factor of 40, implement anomalous diffusion and two-component …

Characterization, Immobilization, And Polymer Related Applications Of Watermelon Seed Powder, A Practical Source Of Urease Enzyme, Anthony Quan Quoc Mai

LSU Doctoral Dissertations

Urease enzyme was crystallized almost a century ago, and to this day its intrinsic stability is not ideal for everyday applications. This work introduces a new process by which a naturally encapsulated material, watermelon seed powder (WMSP), is characterized for its stability and activity. WMSP enzymatic activity has been measured for over a year at various storage conditions—exposed to ambient atmosphere for a year, WMSP retained above 90% activity. In aqueous conditions, the enzyme maintained above 60% activity after two months; with the addition of a preservative that number stays at about 90%. There is a pH shift of the …

Soil C:N:P Stoichiometry In Tropical Forests On Hainan Island Of China: Spatial And Vertical Variations, Dafeng Hui, Xitian Yang, Qi Deng, Qiang Liu, Xu Wang, Huai Yang, Hai Ren

Biology Faculty Research

Soil carbon (C), nitrogen (N), and phosphorus (P) are three important elements. The study of stoichiometric relationships of soil C, N, and P in tropical forests on Hainan Island, China could improve our understanding of nutrient cycling and provide valuable information for forest management. Soil samples were collected at five different depths from 0 to 100 cm at 100 sites among four different forest types on Hainan Island, and total C, N, and P concentrations were measured. Soil C and N concentrations and soil C:P and N:P ratios declined from the surface soil layer to the deeper soil layers and …

Investigation Of The Structure And Dynamics Of Novel Battery Electrolytes By Utilizing Multidimensional Infrared Spectroscopic Techniques, Susith Rajitha Abeythunga Galle Kankanamge

LSU Doctoral Dissertations

Novel battery technologies are being developed due to the high global demand for energy in many fields where different specifications are required. The battery electrolyte provides a medium for ions to diffuse between electrodes and its composition determines the compatibility with the electrode pair. While many works focus on characterizing novel electrolyte systems to advance new batteries, the understanding of the microscopic structure and dynamics of speciations present in these electrolytes is limited. Many experiment methods have obtained incomplete time-averaged structure information due to lack of instrumental time resolution compared to the molecular intrinsic time sales of electrolytes that range …

Changes At A Critical Branchpoint In The Anthocyanin Biosynthetic Pathway Underlie The Blue To Orange Flower Color Transition In Lysimachia Arvensis, Mercedes Sánchez-Cabrera, Francisco Javier Jiménez-López, Eduardo Narbona, Montserrat Arista, Pedro L. Ortiz, Francisco J. Romero-Campero, Karolis Ramanauskas, Boris Igić, Amelia A. Fuller, Justen B. Whittall

Chemistry and Biochemistry

Anthocyanins are the primary pigments contributing to the variety of flower colors among angiosperms and are considered essential for survival and reproduction. Anthocyanins are members of the flavonoids, a broader class of secondary metabolites, of which there are numerous structural genes and regulators thereof. In western European populations of Lysimachia arvensis, there are blue- and orange-petaled individuals. The proportion of blue-flowered plants increases with temperature and daylength yet decreases with precipitation. Here, we performed a transcriptome analysis to characterize the coding sequences of a large group of flavonoid biosynthetic genes, examine their expression and compare our results to flavonoid biochemical …

Three-Color Plasmon-Mediated Reduction Of Diazonium Salts Over Metasurfaces., Denis A B Therien, Danielle M Mcrae, Claire Mangeney, Nordin Félidj, François Lagugné-Labarthet

Chemistry Publications

Surface plasmon-mediated chemical reactions are of great interest for a variety of applications ranging from micro- and nanoscale device fabrication to chemical reactions of societal interest for hydrogen production or carbon reduction. In this work, a crosshair-like nanostructure is investigated due to its ability to induce local enhancement of the local electromagnetic field at three distinct wavelengths corresponding to three plasmon resonances. The structures are irradiated in the presence of a solution containing diazonium salts at wavelengths that match the resonance positions at 532 nm, 632.8 nm, and 800 nm. The resulting grafting shows polarization and wavelength-dependent growth patterns at …

Identifying Receptors For Neuropeptides And Peptide Hormones: Challenges And Recent Progress, Md Shadman Ridwan Abid, Somayeh Mousavi, James W. Checco

Department of Chemistry: Faculty Publications

Intercellular signaling events mediated by neuropeptides and peptide hormones represent important targets for both basic science and drug discovery. For many bioactive peptides, the protein receptors that transmit information across the receiving cell membrane are not known, severely limiting these signaling pathways as potential therapeutic targets. Identifying the receptor(s) for a given peptide of interest is complicated by several factors. Most notably, cell-cell signaling peptides are generated through dynamic biosynthetic pathways, can act on many different families of receptor proteins, and can participate in complex ligand-receptor interactions that extend beyond a simple one-to-one archetype. Here, we discuss recent methodological advances …

Career: Time-Resolved Studies Of Charge Transfer And Chemical Reactivity At Photoelectrode-Electrolyte Interfaces, Yi Rao

Funded Research Records

No abstract provided.

Review Of Chemoselective Reagent Based-Breath Analysis Techniques, Madeline F. Mccloud

Grawemeyer Colloquium Papers

Volatile organic compounds (VOCs) pose a threat due to the negative effects of many compounds on human health. VOCs of interest are specific carbonyl compounds produced exogenously and endogenously, resultant of industrial pollution and diseases such as cancer. High concentrations of these carbonyl compounds are found in exhaled breath are linked to cancer, therefore non-invasive breath tests would prove beneficial for cancer diagnosis. Usage of chemoselective cationic reagents allows for efficient testing of these concentrations. The development of these breath tests is detailed in the report.

Rotaxane Rings Promote Oblique Packing And Extended Lifetimes In Dna-Templated Molecular Dye Aggregates, Matthew S. Barclay, Simon K. Roy, Jonathan S. Huff, Olga A. Mass, Daniel B. Turner, Christopher K. Wilson, Donald L. Kellis, Jeunghoon Lee, Paul H. Davis, Bernard Yurke, William B. Knowlton, Ryan D. Pensack

Chemistry and Biochemistry Faculty Publications and Presentations

Molecular excitons play a central role in natural and artificial light harvesting, organic electronics, and nanoscale computing. The structure and dynamics of molecular excitons, critical to each application, are sensitively governed by molecular packing. Deoxyribonucleic acid (DNA) templating is a powerful approach that enables controlled aggregation via sub-nanometer positioning of molecular dyes. However, finer sub-Angstrom control of dye packing is needed to tailor excitonic properties for specific applications. Here, we show that adding rotaxane rings to squaraine dyes templated with DNA promotes an elusive oblique packing arrangement with highly desirable optical properties. Specifically, dimers of these squaraine:rotaxanes exhibit an absorption …

Disaggregation Of Nanodiamond Particles, Vadym Mochalin, Atsushi Kume, Yoshihiro Inamoto, Masumi Hashimoto

Chemistry Faculty Research & Creative Works

Methods for disaggregating nanodiamond clusters, for example, by using sonication to break apart nanodiamond aggregates in an aqueous slurry having an alkaline pH. Compositions, such as aqueous nanodiamond dispersions and dry particulate compositions can be produced using these methods.

Using Molecular Dynamics Simulations To Understand Receptor-Complex Communication And Signaling, Hannah Margaret Hoag

Theses and Dissertations

The overarching purpose of this document is to use Computer-aided drug design and Molecular dynamic simulations to better understand elusive drug-receptor interactions, as well as various types of inter-receptor signaling. Chapter One introduces the theory and importance of Computer-aided drug design and the methodology used in both Chapters Two and Three.

Chapter Two uncovers the relationship between the well-studied ABCB1 transporter and a newly identified drug known as Xanthohumol (XN). XN is compared to a commonly used drug, Doxorubicin (DOX), in this chapter. If the ABCB1 transporter can be properly inhibited, cancer-fighting drugs will be able to stay within the …

P53 Is Potentially Regulated By Cyclophilin D In The Triple-Proline Loop Of The Dna Binding Domain, Jacques Kumutima, Xin-Qiu Joe Yao, Donald Hamelberg

Chemistry Faculty Publications

The multifunctional protein p53 is the central molecular sensor of cellular stresses. The canonical function of p53 is to transcriptionally activate target genes in response to, for example, DNA damage that may trigger apoptosis. Recently, p53 was also found to play a role in the regulation of necrosis, another type of cell death featured by the mitochondrial permeability transition (mPT). In this process, p53 directly interacts with the mPT regulator cyclophilin D, the detailed mechanism of which however remains poorly understood. Here, we report a comprehensive computational investigation of the p53–cyclophilin D interaction using molecular dynamics simulations and associated analyses. …

Mineralogy And Geochemistry Of Shale-Hosted Copper Of The Middle Buanji Group, Chimala Area, South-Western Tanzania, Almachius Mutasingwa, Michael Msabi, Neema Jackson, Seetharamaiah Jagarlamudi

Tanzania Journal of Science

The mineralogical and geochemical assessments are presented in this paper to constrain the mineralogy and copper concentrations of the shale-hosted copper in the Middle Buanji Group of the Upper Paleoproterozoic (1.67 Ga). The XRD analysis revealed that illite and chamosite are the major clay minerals present in the shales together with pseudomalachite, quartz, and muscovite that constitute over 95% by proportion of the sample. The minerals biotite, birnessite, ferroselite, bearsite, chloritoid, and anatase are present in association with shale-hosted copper in low amounts (i.e., <5% by proportion of the sample). The pseudomalachite [Cu5(PO4)2(OH)4] is considered as ore mineral of copper in the shales of the Middle Buanji Group. Field observations revealed the presence of different shale layers within the Middle Buanji Group such as red, grey and green/blue in which copper mineral is distributed. On average, the copper concentrations in the shale layers were unevenly distributed throughout the red-grey-green shales layers with values of 0.31 wt%, 5.2 wt% and 13.19 wt%, respectively. A noticeable amount of copper mineralization up to 25.7 wt% was restricted within the green shale layer as compared to red (0.31 wt%) and grey (10.9 wt%) layers. Keywords: Pseudomalachite; Supergene enrichment; Shale-hosted copper; Green shale layer

Corrosion Inhibition Of Mild Steel In Seawater By 2,4,6-Triamino-3-Pentadecylphenyl Acetate Derived From Cashew Nut Shell Liquid, Emanuel Ricky, Esther Lugwisha, Joseph Philip

Tanzania Journal of Science

The corrosion inhibition performance of 2,4,6-triamino-3-pentadecylphenyl acetate on mild steel in seawater at stationary condition, 30 °C and pH 8 was investigated using potentiodynamic polarization and electrochemical impedance spectroscopy. The maximum inhibition efficiency of 93% was found in the presence of 300 ppm of 2,4,6-triamino-3-pentadecylphenyl acetate for both potentiodynamic polarization and electrochemical impedance spectroscopy techniques. The potentiodynamic polarization curves show that 2,4,6-triamino-3-pentadecylphenyl acetate acts as a mixed type inhibitor which influences more the anodic processes. The Nyquist plots revealed that the polarization resistance (Rp) increases whereas the double-layer capacitance (Cdl) and corrosion current density (icorr) decrease as the concentrations of …

Physicochemical And Sensory Evaluation Of Mixed Juices From Banana, Pineapple And Passion Fruits During Storage, Victor Matabura, Oscar Kibazohi

Tanzania Journal of Science

Juices from fresh fruits offer various health benefits, including strengthening the immune system and preventing diseases. Mixed fruit juices tend to have good nutritional contents and organoleptic properties like colour, flavour, taste, and overall appeal of different fruits. This work investigated the physicochemical and sensory attributes of fruit juice of low viscosity banana juice blended with pineapple and passion juices. The prepared juices were pasteurised at 92 °C for 15 s, bottled in air-tight glass bottles, and subsequently stored in two different conditions: an ambient temperature of approximately 28 ± 2 °C and a fridge at 4 ºC for one …

Diverse Co-Teaching: A One-Step Strategy For Assessment, Integration, Collegiality, Transformation, Professional And Personal Growth For The University Community, Darrell R. Fry, Odutayo O. Odunuga

Diversity Conference

Dr. Fry

Dr. Odunuga

Dr. Fry and Dr. Odunuga are two very different people. Yet the two share a passion for teaching chemistry and a desire to bring out the best in their students. Since 2016 the two have co-taught chemistry lectures and laboratories, and in this presentation they share their experiences and the benefits of diverse co-teaching. Diverse co-teaching naturally provides students, faculty and staff with a transformational experience, and serves as a universal platform for integrating various groups, promoting collegiality and performing assessment.

Summarized below are some items of the transformation that each audience within the university may …

Determination Of The Rydberg Constant From The Emission Spectra Of H And He+, Kyle D. Shaffer

Ramifications

Abstract

In this experiment, the Rydberg constants for the hydrogen atom and He⁺ were determined by analysis of the emission spectra of Hand He, respectively, in comparison to the principal quantum numbers of each transition. Using both a hydrogen and then a helium atomic lamp attached to a 0.5 m grating spectrometer and a photomultiplier detector (PMT), a change in voltage detected by the PMT can be paired with a corresponding wavelength passing through the spectrometer from each emission peak in the visible to ultraviolet range. The peaks acquired from this change in voltage were analyzed to find their …

Combination Therapy: Dual Drug-Loaded Superparamagnetic Iron-Oxide Nanoparticle For Targeted Drug Delivery And Treatment Of Cancer, Himanshu Polara

Electronic Theses & Dissertations

Lung cancer is the most occurring form of cancer of all ages in the United States after breast cancer. Many treatments are currently available in the market to treat cancer, but they all have some side effects. The concept of nanomedicine-based targeted drug delivery has been developed to overcome the limitations of current treatment. The advantages of this method of treatment include biocompatibility, significant toxicity towards cancer cells, immediate drug response, and fewer side effects. For the specific treatment of A549 lung cancer cells, polyacrylic acid (PAA) coated Iron Oxide Nanoparticle (IONP) were introduced for magnetic resonance imaging (MRI) of …

An Investigation Of Cross-Links On Crystallization And Degradation In A Novel, Photocross-Linkable Poly (Lactic Acid) System, Nicholas Baksh

USF Tampa Graduate Theses and Dissertations

Polymeric molecular structure consists of repeating units bonded together. Mechanicalproperties can be altered without affecting chemical makeup by altering the number of these units. Small molecules can be introduced and/or polymers can be modified to form bonds between molecular chains. Cross-linking, as this is called, also introduces mechanical variation with minimal effects on chemical composition. Lastly, polymer chains reorient themselves in response to intermolecular forces. This temperature dependent response is known as crystallization. Although chemistry is unaltered, mechanical properties can depend highly on the percent of the sample that is crystallized.

Cross-linking is known to enhance the mechanical properties of …

A Composite Textual Phenomenological Approach To Cures Versus Traditional Laboratory Experiences, Amie S. Sommers, Dana Richter-Egger, Christine E. Cutucache

The Qualitative Report

Here we present unique perspectives from undergraduate students (n=3) in STEM who have taken both a traditional laboratory iteration and a Course-based Undergraduate Research Experience (CURE) iteration of the same introductory chemistry course. CUREs can be effective models for integrating research in courses and fostering student learning gains. Via phenomenological interviews, we asked students to describe the differences in their perspectives, feelings, and experiences between a traditional lab guided by a lab manual and a CURE. We found that (i.) critical thinking/problem solving, (ii.) group work/collaboration, (iii.) student-led research questions and activities, and (iv.) time management are the top four …

Measurement Report: Sulfuric Acid Nucleation And Experimental Conditions In A Photolytic Flow Reactor, David R. Hanson, Seakh Menheer, Michael Wentzel, Joan Kunz

Faculty Authored Articles

Nucleation rates involving sulfuric acid and water measured in a photolytic flow reactor have decreased considerably over a time period of several years. Results show that the system flow reactor, gas supplies and lines, flow meters, valves, H2SO4 photo-oxidant sources has reached a baseline stability that yields nucleation information such as cluster free energies. The baseline nucleation rate is punctuated by temporary bursts that in many instances are linked to cylinder changes, delineating this source of potential contaminants. Diagnostics were performed to better understand the system, including growth studies to assess H2SO4 levels, chemiluminescent NO and NOx detection to assess …