Chemistry Commons^™

Sustainable Non-Noble Metal Based Catalysts For High Performance Oxygen Electrocatalysis, Swetha Ramani

USF Tampa Graduate Theses and Dissertations

Current energy crisis has dramatically shifted the focus of technological advancements towards clean and renewable forms of energy. Continued dependence and utilization of fossil fuels has created global awareness on harmful greenhouse gas emissions and climate change. A need for sustainable technology has gained a lot of significance in the recent years. This has led to the development of devices and technologies that rely on environmentally friendly electrochemical conversion and storage of energy. One such advancement that generates electrical energy from chemical reactions is known as fuel cell technology. While fuel cells have demonstrated potential in replacing the conventional technologies …

Near-Infrared Boron Difluoride Formazanate Dyes, Francis L. Buguis, Ryan R. Maar, Viktor N. Staroverov, Joe Gilroy

Chemistry Publications

Near-infrared (NIR) dyes are sought after for their utility in light harvesting, bioimaging, and light-mediated therapies. Since long-wavelength photoluminescence typically involves extensive p-conjugated systems of double bonds and aromatic rings, it is often assumed that NIR dyes have to be large molecules that require complex syntheses. We challenge this assumption by demonstrating that facile incorporation of tertiary amine groups into readily available 3-cyanoformazans affords efficient production of relatively simple NIR-active BF₂ formazanate dyes (λ_abs = 691−760 nm, λ_PL = 834−904 nm in toluene). Cyclic voltammetry experiments on these compounds reveal multiple reversible redox waves linked to the …

Investigation Of The Evaporation Rate Of Water From Colloidal Unimolecular Polymer (Cup) Systems By Isothermal Tga, Peng Geng, Ashish Zore, Michael R. Van De Mark

Chemistry Faculty Research & Creative Works

Studies of the evaporation of aqueous nanoparticle solutions have been limited due to lack of homogeneity of the solution, difficulties in obtaining reproducible samples and stability of substrates, as well as the effect of other volatile components or contaminants such as surfactants. Colloidal unimolecular polymer (CUP) is a spheroidal nanoparticle with charged hydrophilic groups on the surface, and the particle size ranges from 3 to 9 nm. The large amount of surface water on the CUP surface provides the opportunity to evaluate the evaporation of surface water, which may contribute to the investigation the factors that affect the evaporation rate …

Chapter 1.1: 3-D Surface Visualization Of Ph Titration “Topos”: Equivalence Point Cliffs, Dilution Ramps And Buffer Plateaus, Garon C. Smith, Md Mainul Hossain, Patrick Maccarthy

Water Topos: A 3-D Trend Surface Approach to Viewing and Teaching Aqueous Equilibrium Chemistry

3-D topos can be generated to visualize how pH behaves during titration and dilution procedures. The surfaces are constructed by plotting computed pH values above a composition grid with volume of base added in one direction and overall system dilution on the other. Surficial features correspond to behavior in aqueous solutions. Equivalence point breaks become cliffs that pinch out with dilution. Buffer effects become plateaus. Dilution alone generates 45^o ramps. Sample surfaces are analyzed for acetic acid, CH₃COOH (a weak monoprotic acid); hydrochloric acid, HCl (a strong acid); oxalic acid, HOOCCOOH (a weak diprotic acid) and L-histidine …

A New Lc-Ms/Ms Technique For Separation Of Gangliosides Using A Phenyl-Hexyl Column: Systematic Separation According To Sialic Acid Class And Ceramide Subclass, Ashta Lakshmi Prasad Gobburi, Eric Wekesa Kipruto, Denise M. Inman, David J. Anderson

Chemistry Faculty Publications

A LC-MS/MS technique separated the bovine and mouse brain gangliosides monosialotetrahexosylgangliosides (GM1), disialotetrahexosylgangliosides (GD1a), trisialotetrahexosylgangliosides (GT1b) and tetrasialotetrahexosylgangliosides (GQ1b) using a phenyl-hexyl HPLC column and employing a linear methanol gradient in water, which is 0.028% in ammonium hydroxide. The gangliosides were separated according to sialic acid class, and within a particular class, gangliosides having different ceramide carbon chain lengths were also separated. All gangliosides of a particular sialic acid class eluted in characteristic retention time windows in the order of GQ1b, (earliest), GT1b, GD1a, and GM1 (latest). Within each specific retention time window for a particular ganglioside class, gangliosides were …

Microbiological, Physicochemical, And Immunological Analysis Of A Commercial Cashew Nut-Based Yogurt, Christopher P. Mattison, Kayanush Aryana, Kristen Clermont, Eric Prestenburg, Steven W. Lloyd, Casey .. Grimm, Richard L. Wasserman

Faculty Publications

Nut-based milks and yogurts are gaining popularity, but may not offer the same benefits as dairy yogurts to consumers. Cashew nuts often cause severe allergic reactions, and cashew nut allergens are stable to several types of processing. To compare its characteristics to dairy yogurt and characterize the effects of fermentation on the Ana o 1-3 cashew nut allergens, a commercial yogurt made from cashew nuts (Cashewgurt) was evaluated for microbiological, physiochemical, and immunological properties. Average counts for lactobacilli and Streptococcus thermophilus were greater than 10 million colony forming units per milliliter, indicating the capacity to provide a health benefit. Cashewgurt …

A Novel Mutation Of The Narrow Leaf 1 Gene Adversely Affects Plant Architecture In Rice (Oryza Sativa L.), Prasanta K. Subudhi, Richard S. Garcia, Sapphire Coronejo, Teresa B. De Leon

Faculty Publications

Plant architecture is critical for enhancing the adaptability and productivity of crop plants. Mutants with an altered plant architecture allow researchers to elucidate the genetic network and the underlying mechanisms. In this study, we characterized a novel nal1 rice mutant with short height, small panicle, and narrow and thick deep green leaves that was identified from a cross between a rice cultivar and a weedy rice accession. Bulked segregant analysis coupled with genome re-sequencing and cosegregation analysis revealed that the overall mutant phenotype was caused by a 1395-bp deletion spanning over the last two exons including the transcriptional end site …

Ion-Molecule Interactions Enable Unexpected Phase Transitions In Organic-Inorganic Aerosol, David S. Richards, Kristin L. Trobaugh, Josefina Hajek-Herrera, C. L. Price, C. S. Sheldon, J. F. Davies, Ryan D. Davis

Chemistry Faculty Research

Atmospheric aerosol particles are commonly complex, aqueous organic-inorganic mixtures, and accurately predicting the properties of these particles is essential for air quality and climate projections. The prevailing assumption is that aqueous organic-inorganic aerosols exist predominately with liquid properties and that the hygroscopic inorganic fraction lowers aerosol viscosity relative to the organic fraction alone. Here, in contrast to those assumptions, we demonstrate that increasing inorganic fraction can increase aerosol viscosity (relative to predictions) and enable a humidity-dependent gel phase transition through cooperative ion-molecule interactions that give rise to long-range networks of atmospherically relevant low-mass oxygenated organic molecules (180 to 310 Da) …

Topology And Control Of Self-Assembled Domain Patterns In Low-Dimensional Ferroelectrics, Y. Nahas, S. Prohorenko, Q. Zhang, V. Govinden, N. Valanoor, L. Bellaiche

Physics Faculty Publications and Presentations

Whilst often discussed as non-trivial phases of low-dimensional ferroelectrics, modulated polar phases such as the dipolar maze and the nano-bubble state have been appraised as essentially distinct. Here we emphasize their topological nature and show that these self-patterned polar states, but also additional mesophases such as the disconnected labyrinthine phase and the mixed bimeron-skyrmion phase, can be fathomed in their plurality through the unifying canvas of phase separation kinetics. Under compressive strain, varying the control parameter, i.e., the external electric field, conditions the nonequilibrium self-assembly of domains, and bridges nucleation and spinodal decomposition via the sequential onset of topological transitions. …

Nicotine In Tobacco Product Aerosols: 'It's Deja Vu All Over Again', Anna K. Duell, James F. Pankow, David H. Peyton

Chemistry Faculty Publications and Presentations

Introduction: The distribution of nicotine among its free-base (fb) and protonated forms in aerosolised nicotine affects inhalability. It has been manipulated in tobacco smoke and now in electronic cigarettes by the use of acids to de-freebase nicotine and form ‘nicotine salts’.

Methods: Measurements on electronic cigarette fluids (e-liquids) were carried out to determine (1) the fraction of nicotine in the free-base form (α fb) and (2) the levels of organic acid(s) and nicotine. Samples included JUUL ‘pods’, ‘look-a-like/knock-off’ pods and some bottled ‘nicotine salt’ and ‘non-salt’ e-liquids.

Results: α fb= 0.12 ±0.01 at 40°C (≈ 37°C) for 10 JUUL products, …

One-Pot O-Alkylation And C-C Cross-Coupling Reactions Involving Stabilized Phosphoranes, Areej Hashim Mohamed

Theses

This thesis is concerned with the one-pot reactions that are considered to be beneficial to preserve resources, save time, and are deemed a green chemistry strategy. To plan such one-pot reactions, it is important to combine two or more reactions that are compatible with each other and can be run under the same reaction conditions. In this work, possibilities of a combination of Wittig-olefination and Suzuki C-C-cross coupling reactions are explored further. Reaction sequences involve the combination of a Suzuki-reaction / Wittig olefination, a Suzuki reaction / Wittig olefination/hydrolysis, and a Suzuki-reaction / double Wittig olefination. In all cases, stabilized …

Estimation Of The Removal Of Chiral Pharmaceutical Drugs From Domestic Wastewater Using Uplc-Ms/Ms, Mohammed Khaled Al Tabaji

Theses

This thesis is concerned with the estimation of the removal of chiral pharmaceutical compounds (PCs) from domestic wastewater in Al Ain using UPLC-MS/MS. PCs are classified into many classes such as hormones, antibiotics, analgesics, cosmetic products, ꞵ blockers, and anti-inflammatory drugs. PCs do not have a guideline to describe their concentrations in treated domestic wastewater. Additionally, there is a very high demand for using PCs around the world, which results in their discharge to wastewater at relatively high masses, which could be harmful to the environment. Furthermore, very limited work has been done to estimate the removal of chiral PCs. …

Determination Of Vitamin D Metabolites And Their Epimers In Obese Emirati Population, Bashar Hiatham Alzohily

Theses

Vitamin D deficiency is a global issue, and despite all-year-round sunshine, it is a big problem in the UAE. Obesity or overweight refers to an accumulation of excessive fat that may harm health so, it is considered a worldwide health concern. The accurate measurement of vitamin D active forms is a problematic issue. This study aimed to develop and validate a UHPLC-MS/MS method for the new method for determining vitamin D levels in the obese Emirati population. The vitamin D epimers and other metabolites were determined by UHPLC-MS/MS system, model 8060. The methods include the collection of blood samples from …

Development Of Supramolecular Multicomponent Chromophores Towards Photoluminescence Switches, Rukayat Shola Bojesomo

Theses

A new fluorescent dye (4PBZC) comprises of coumarin (C), piperazine (P), and benzimidazole (BZ) was designed, prepared, and complexed to cucurbit[7]uril (CB7) to detect carnosol (CAR), an anti-breast cancer drug, in sub-nanomolar concentrations utilizing the supramolecular indicator displacement assay (IDA) strategy, the CB7-assisted pK_a shift and the CB7-retarded photoinduced electron transfer (PET) process. The host−guest complexation was confirmed by UV−visible absorption, fluorescence, and proton NMR spectroscopy, which confirm binding to 4PBZC via the BZ moiety. Also, CB7 preferentially binds the indicator dye via the protonated BZ residue compared to the neutral BZ one, demonstrated by a higher binding …

Synthesis, Characterization, Electronic Structure Of Biocl/Biobr/Rgo Ternary Heterojunction And Its Photocatalytic Activities, Salama Yousef Alismaail

Theses

Solar energy is free, most abundant among all renewable energy sources. Energy from the sun reaches the earth surface at a rate of 1.2 X 10⁵ TW by far, exceeding the current world energy consumption of 17 TW (1TW = 10¹² J/s). Accordingly, development of visible light driven photocatalysts is of considerable interest in clean and renewable energy, as well as in wastewater treatment.

In that context, BiOCl and BiOBr and three different mole ratio composites were prepared, characterized using UV-vis DRS, PXRD, BET, SEM, and EDX and their photocatalytic activity for the photoreduction of 4-NA was evaluated. …

Mass Spectrometric Determination Of Retinol In Emirati Population, Israa Samir Mohamed Shawky El-Konaissi

Theses

This thesis is concerned with analyzing vitamin A deficiency. Vitamin A is crucial for several functions, including vision, growth, and cell differentiation. the main aim is to develop and validate an LC-MS/MS method for the determination of vitamin A in plasma matrix and use the new method for the determination of vitamin A levels in the obese Emirati population. Methods: A positive ion electrospray ionisation (ESI) LC-MS/MS method was used in the Multiple Reaction Monitoring (MRM) mode for quantification. It involved i) LC-MS/MS, ii) a guard column together with C18 Ascentis Express F5 column iii) Internal standard, 25-Hydroxyvitamin D3 (6, …

Lead Complexation By Humic Acids And Their Analogs: A Voltammetric Study, Spencer Steinberg, Vernon Hodge

Chemistry and Biochemistry Faculty Research

© 2020 by the authors. Licensee MDPI, Basel, Switzerland. Differential pulse polarography (DPP) was used to assess the interaction of Pb2+ with various humic acid analogs and several humic acids. DPP analysis demonstrated that the reduction peak maximum (Ep) for Pb2+ shifted to more negative values in the presence of humic acids and humic acid analogs. The observed Ep for Pb2+ in the presence of humic acids and humic acid analogs is influenced by ligand concentration, solution pH and Pb2+ concentration. Shifts in the Ep for Pb2+ are related to the reduction potential and can be rationalized using the Lingane …

Increasing The Bioavailability Of Poorly Soluble Anti-Cancer Prodrugs Through Encapsulation In Platinum Based Nanocages, Salim Cesar Lutfallah

Honors Capstones

No abstract provided.

Electromagnetic-Triboelectric-Hybrid Energy Tile For Biomechanical Green Energy Harvesting, Elaijah Islam, Abu Musa Abdullah, Aminur Rashid Chowdhury, Farzana Tasnim, Madelyne Martinez, Carolina Olivares, Karen Lozano, Mohammed Uddin

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

Highlights

• Hybrid nanogenerator based floor-tile was developed to convert the Bio-Mechanical energy of human footsteps to Electrical Energy.

• Hybridization of Triboelectric Nanogenerator and Electro-Magnetic Generator consisting of Aluminum and Kapton.

• MoS2 is working as an electron acceptor.

• The maximum output is 1200V as open-circuit voltage, 5mA as short-circuit current, and 6W as power.

• Produces 20% more power than a commercially sold energy-harvester floor tile.

Abstract

Since the invention of Piezoelectric Nanogenerator in 2006, nanogenerators has become an attractive technology to the researchers for scavenging mechanical energy from the ambient environment for real life applications. Hybridization of these nanogenerators has been …

Ion Pairing Versus Solvation Of Dinitrobenzene Anions In Room-Temperature Ionic Liquids (Rtils): Vibrational Signatures Of Rtil–Substrate Interactions, Abderrahman Atifi, Piotr J. Mak, Michael D. Ryan

Chemistry Faculty Research and Publications

The mechanism of solvation of ions by ionic liquids is more complex than solvation in most molecular solvents as the ionic liquid itself provides the counter ion. Solvation and ion pairing of anionic substrates in room-temperature ionic liquids (RTILs) were investigated using resonance Raman spectroscopy and DFT calculations. The purpose of this study was to differentiate between the formation of discrete cation/anion structures and a double-layer cloud of counter ions without specific atomic interactions between the ionic species. In acetonitrile/RTIL mixtures, the radical anion and dianion of dinitrobenzene (DNB) are stabilized by RTILs through solvation and ion pairing. The formation …

Synthesis And Ftir Characterization Of Mg-Hydroxylapatite Derived From Dolostone With High Dolomite Mineral Content, Wilson L. Mahene, Charles Gervas, Askwar H. Hilonga, Revocatus L. Machunda

Tanzania Journal of Science

We present the synthesis of magnesium-substituted hydroxylapatite starting from locally available dolostone. The apatite was prepared by a reaction between heat pre-treated dolostone powder with phosphoric acid, maintained at the pH of 12.5 using sodium hydroxide. The resultant material was then calcined at 500 °C, 600 °C, 700 °C, 800 °C and 900 °C. The precursor dolostone was characterized by organic elemental analyser (CHNS-O analyser), X-ray fluorescence (XRF) and Fourier transform infrared spectroscopy (FTIR), while the synthesized material was characterized by using FTIR. Results indicated that the dominant mineral in the carbonate rock materials was near-stoichiometric dolomite, while the synthesized …

Geological And Geochemical Characterisation Of Pegmatites Around Olode, Southwestern Nigeria, Razak O. Jimoh, Akinade S. Olatunji

Tanzania Journal of Science

Olode is prolific in terms of pegmatites, occurring in different ways as large intrusive bodies, as veins and dykes, discordantly intruding the host rocks of mica schist, gneiss and granite. This study is aimed at the geological and geochemical characterisation of pegmatites around Olode. Field investigation was undertaken to determine the occurrences and relationships of the pegmatites with the host rocks. Fresh pegmatite samples were studied petrographically and geochemically. Two main lithologically and chronologically different groups of pegmatites were distinguishable in the study area. These were the tourmaline pegmatites associated with the Older Granite rocks and the NE-SW trending beryl-bearing …

Comparison Of Centrifugation And Solid Phase Extraction (Spe) Methods Of Sample Preparations In Determination Of Residues Of Drugs Of Abuse In Urine, John Mahugija, Anastazia Wandwi, Kessy Kilulya

Tanzania Journal of Science

Detection of drugs of abuse in urine samples depends on their composition, absorption, distribution, physical and chemical properties, concentrations, elimination properties, and the techniques employed. This study compared the performance of centrifugation and solid phase extraction (SPE) methods in the determination of levels of drugs of abuse and their metabolites in urine samples collected from drug abusers. Analysis was performed using liquid chromatography-tandem mass spectrometry (LC-MS-MS). Calibration was done using both internal and external standards. The recovery values were generally greater in centrifugation method than in SPE method, but the recoveries in both methods were within an acceptable range. Linearity …

Preliminary Quantitative And Qualitative Investigations On The Heterogeneous, Irreversible Uptake Of Acetone By Titanium(Iv) Oxide, John S. André, Natalie Eskandary, Terry Franklin, Emilia J. Mccann, Oscar Pascual-Diaz, Gregory M. Pitch, Jesus D. Rincon, Megan N. Wright, Christopher W. Harmon

IdeaFest: Interdisciplinary Journal of Creative Works and Research from Cal Poly Humboldt

No abstract provided.

Corrigendum To “Biosynthesis Of Desferrioxamine Siderophores Initiated By Decarboxylases: A Functional Investigation Of Two Lysine/Ornithine-Decarboxylases From Gordonia Rubripertincta Cwb2 And Pimelobacter Simplex Vkm Ac-2033d” [Arch. Biochem. Biophys. 689 (2020) 108429] (Archives Of Biochemistry And Biophysics (2020) 689, (S0003986120304380), (10.1016/J.Abb.2020.108429)), Marika Hofmann, Julia S. Martin Del Campo, Pablo Sobrado, Dirk Tischler

Chemistry Faculty Research & Creative Works

The authors regret that mistakenly the wrong strain was named in the article title. The decarboxylase gene psdesA originates from Pimelobacter simplex VKM Ac-2033D, not from Pimelobacter simplex 3E. The authors would like to apologize for any inconvenience caused.

Development And Characterization Of Robust Methods For Field Investigations With Portable Mass Spectrometry, Ashley Rose Stelmack

Theses and Dissertations

Portable mass spectrometry (MS) has become an area of interest due to the ability to conduct chemical analyses in native environments. These instruments have the potential to increase efficiency and analytical throughput via real-time experimentation, minimizing the need for sample transportation. One drive towards the development of fieldable mass spectrometers is the potential for coupling to novel ambient ionization methods (or “ambient MS”), which can generate spectral data at ambient conditions from unprepared or minimally prepared samples of interest. Since the first introduction of the desorption electrospray ionization (DESI) technique in 2004, a myriad of novel techniques have been reported …

Population Genetics Of Rhizophora Apiculata In Peninsular Malaysia Using Microsatellite Markers, Amelia Azman

Student Works (2020-2029)

Rampant illegal logging, overharvesting and deforestation coupled with climate change, pose significant threats to the natural stands of Rhizophora apiculata, or locally known as Bakau Minyak; one of the most economically and ecologically important species of mangroves in Peninsular Malaysia. Despite being a dominant mangrove species, the reduction in the number of R. apiculata in its habitat has resulted in concerns over the long-term survival potential of the species. In Malaysia, genetic information to develop effective guidelines for the conservation and management of mangrove species has been lacking, and hence, further research should be conducted to fill this gap. The …

Facile Synthesis Of Nitrogen-Doped Graphene-Like Active Carbon Materials For High Performance Lithium-Sulfur Battery, Quan-Hua Meng, Wen-Wen Deng, Chang-Ming Li

Journal of Electrochemistry

Lithium-sulphur (Li-S) battery is regarded as a promising energy storage device because of its high theoretical capacity. However, the low S utilization and short cycling life limit the commercial applications. In this work, nitrogen-doped graphene-like carbon (NGC) materials were synthesized by simply pyrolyzing and carbonizing the mixture of melamine (C₃H₆N₆) and L-cysteine (C₃H₇NO₂S). The graphene-like structure in NGC effectively buffered the volume change of S during the discharge/charge process and improved the cycling stability. Meanwhile, nitrogen-containing functional groups in NGC facilitated the transportation of ions and suppressed the …

Electrochemical Engineering Of Carbon Nanodots, Lei Bao, Dai-Wen Pang

Journal of Electrochemistry

Aqueous batteries have been considered to be a competitive candidate for large-scale energy storage. However, most of aqueous batteries adopt inorganic electrode materials with metallic elements, which are based on the reversible insertion of metal ions, making their application being highly hindered by limited cycle life, environmental issue, high cost and low reserves. On the other hand, organic electrode materials offer the advantages of abundant reserves, tunable structures, renewability and environmental benignity. Furthermore, the wide internal space enables these organics to flexibly store various charge carriers. Organics have been investigated as the alternative to inorganic electrode materials. Herein, we review …

Porous-Electrode Theory Of Lithium Ion Battery: Old Paradigm And New Challenge, Xiao-Xiao Wang, Zi-Rui Zhou, Qiang Shan, Zeng-Ming Zhang, Jun Huang, Yu-Wen Liu, Sheng-Li Chen

Journal of Electrochemistry

A critical review on the porous electrode theory developed by Newman and his colleagues is presented. We propose several ideas for further development of this theory by analyzing its limitations. The classical Newman theory does not consider ion steric effect in describing ion transport in electrolyte solutions, which can be amended by a newly developed ion-vacancy coupled charge transfer model for ion transport in concentrated solutions. Ion transport in solid particles of active materials is essentially an ion-electron coupled transport process, and its rationality is verified by comparing the calculated and experimental diffusion coefficients of Li ⁺ ion in intercalation …