Chemistry Commons^™

Polyethersulfone Thin-Film Nanocomposite Membrane Embedded With Amine-Functionalized Graphene Oxide For Desalination Applications, Ahmed Bahaeldin

Theses and Dissertations

Thin-film nanocomposite (TFN) desalination membranes were prepared based on a polyethersulfone (PES) support, where the polyamide (PA) layer was embedded with amine-functionalized graphene oxide (GO). The effect of adding various concentrations of functionalized and un-functionalized GO on the desalination performance, hydrophilicity, and morphology of the membranes was additionally assessed throughout this work. Scanning electron microscopy (SEM) measurements were used to assess the morphology of the membranes in combination with Brunauer-Emmett-Teller (BET) analysis. Contact angle measurements were used to gauge the hydrophilicity of the synthesized membranes. The membrane with the best desalination performance contained 1x10^-3 wt/vol% of functionalized GO in …

Geothermal Energy And Its Impacts On The Environment, Aditi Gorthy, Nathan Tran, Laureen Pierre-Louis

Mako: NSU Undergraduate Student Journal

From the multitude of energy sources that we have developed throughout the eons, renewable energy or “clean energy” has been on the rise to combat global warming and climate change which burning nonrenewable sources of energy have contributed to. Before geothermal energy is used as part of the mainstream energy sources some aspects must be analyzed and resolved. Unfortunately, geothermal power plants still release pollutants, such as carbon dioxide and sulfur dioxide, into the environment and cause general environmental disruptions due to drilling and changes in land formations. Recent and future studies have been and should be conducted to find …

Nanoscale Hafnium Metal-Organic Frameworks Enhance Radiotherapeutic Effects By Upregulation Of Type I Interferon And Tlr7 Expression, Eunseo Choi, Madeleine R. Landry, Nathan Pennock, Katherine Weinfurter, Multiple Additional Authors

Chemistry Faculty Publications and Presentations

Recent preclinical and clinical studies have highlighted the improved outcomes of combination radiotherapy and immunotherapy. Concurrently, the development of high-Z metallic nanoparticles as radiation dose enhancers has been explored to widen the therapeutic window of radiotherapy and potentially enhance immune activation. In this study, we evaluate folate-modified hafnium-based metal-organic frameworks (HfMOF-PEG-FA) in combination with imiquimod, a TLR7 agonist, as a well-defined interferon regulatory factor (IRF) stimulator for local antitumor immunotherapy. The enhancement of radiation dose deposition by HfMOF-PEG-FA and subsequent generation of reactive oxygen species (ROS) deregulates cell proliferation and increases apoptosis. HfMOF-PEG-FA loaded with imiquimod (HfMOF-PEG-FA@IMQ) increases DNA double-strand …

Recent Advances In Exploring Highly Active & Durable Pgm-Free Oxygen Reduction Catalysts, Yuan Li, Miao-Ying Chen, Bang-An Lu, Jia-Nan Zhang

Journal of Electrochemistry

In order to reduce the considerable usage of expensive but scarce platinum at the cathode in proton exchange membrane fuel cells (PEMFCs), it is necessary to pursue alternatives to platinum. The most promising platinum group metal (PGM)-free catalysts for oxygen reduction reaction (ORR) are atomically dispersed, and nitrogen-coordinated metal site catalysts denoted as M-N-C (M = Fe, Co, or Mn, etc.). Over the last few decades, there have been great advances in these catalysts with high ORR activity and promising initial fuel cell performance approaching traditional Pt/C catalysts. However, the stability of these highly active Fe-N-C catalysts under practical fuel …

Research Progress In Cucurbit[N]Uril-Based Metal Nanomaterials For Electrocatalytic Applications, Zong-Nan Wei, Min-Na Cao, Rong Cao

Journal of Electrochemistry

Metal nanomaterials have exhibited excellent performance in electrocatalytic applications, but they still face the problems of poor stability and limited regulation strategies. It is an efficient strategy for greatly enhanced catalytic activity and stability by introducing a second component. In this review, we provide the sketch for the combination of metal nanomaterials and cucurbit[n]urils (CB[n]s) in electrocatalytic applications. CB[n]s are a series of macrocycles with rigid structure, high stability, and function groups for coordinating with metal sites, which make them promising to stabilize and modulate the metal nanomaterials for ideal performance. The discussion classifies the roles of CB[n]s, involving CB[n]s …

Electrochemical Oxidation Of Ethylene On Palladium Electrode, Wei-Xing Wu, Ying Wang

Journal of Electrochemistry

The electrochemical oxidation of C₂H₄ is attracting increasing attention due to its vast potential market. The current electrochemical methods rely on the use of redox mediators, which may produce corrosive intermediates, while direct oxidation is still limited by its low activity and selectivity. Herein, we conducted electrochemical studies to obtain mechanistic insights into the benchmark Pd catalyst. The generated Pd(II) could be the active site for C₂H₄ oxidation. By designing the pulse sequence, we found the ratio of strongly and weakly adsorbed C₂H₄ on Pd to be 0.3:1. The result we …

Preface To Special Issue: Electrocatalysis And Electrosynthesis, Fang-Yi Cheng, Shuang-Yin Wang, Tian-Hua Zhou

Journal of Electrochemistry

No abstract provided.

Supperlattice-Like Structure: Ordered Mass Transfer Endowing High Quality Output Of Fuel Cell, Jian Wang, Wen-Hui Xuan, Qian He, Jing-Xia Jiang, Yuan-Yuan Zhou, Yao Nie, Qiang Liao, Min-Hua Shao, Wei Ding, Zi-Dong Wei

Journal of Electrochemistry

The current or voltage fluctuation in fuel cell operation is harmful to the fuel cell system and power application equipment. Here, we report a technique to eliminate such a fluctuation by the aid of new type of catalysts, superlattice-like mesoporous PtCo catalysts. The current fluctuation in fuel cells catalyzed by two invented catalysts are fixed at as low as 25 mA·cm⁻² with a power of 0.75 W·cm⁻² or 120 mA·cm⁻² with a power of 1.01 W·cm⁻², and no noticeable current decay was detected over 100 h. By contrast, a …

Magnetic Interactions In Open-Shell Conjugated Polymers, Michael Steelman

Dissertations

Most materials are closed shell in which every electron participates in a bond, resulting in unremarkable magnetometry signatures and functionalities. While rare, modern technologies rely on magnetic materials in which unpaired electrons are localized to inorganic atomic centers. In recent decades, a collection of organic open-shell π-conjugated molecules have shown magnetic ordering, albeit at exceedingly low temperatures; a result of weak noncovalent intermolecular interactions limiting long range electronic exchange. Thus, practically applicable sp orbital magnetism that persists at or above room temperature remains a grand challenge for chemistry and physics. Despite the wide variety of chemical structures afforded by organic …

In-Vial Detection Of Protein Denaturation Using Intrinsic Fluorescence Anisotropy, Krishnakumar Chullipalliyalil, Khaled Elkassas, Michael Mcauliffe, Sonja Vucen, Abina Crean

Cappa Publications

The conventional quality control techniques for identifying the denaturation of biopharmaceuticals includes sodium dodecyl sulfate-polyacrylamide gel electrophoresis for identifying fragmentation, ion exchange chromatography and isoelectric focusing for identifying deamidation, reverse-phase high-performance liquid chromatography (HPLC) for identifying oxidation, and size-exclusion HPLC for identifying aggregation. These stability assessments require essential processes that are destructive to the product tested. All these techniques are lab based and require sample removal from a sealed storage vial, which can breach the sterility. In this work, we investigate the heat- and surfactant-induced denaturation of an in-vial-stored model protein, bovine serum albumin (BSA), by analyzing its intrinsic fluorescence …

Lysine Crosslinked Polyacrylamide─A Novel Green Polymer Gel For Preferential Flow Control, Tao Song, Baojun Bai, Yugandhara Eriyagama, Thomas P. Schuman

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Acrylamide-based polymer gels have been applied to control the preferential flow in the subsurface for decades. However, some commonly used crosslinkers, such as Cr (III) and phenol-formaldehyde, are highly toxic and are being phased out because of stringent environmental regulations. This work uses l-lysine as the green crosslinker to produce acrylamide-based polymer gels. This article systematically studied the effect of lysine and polymer concentration, salinity, pH, and temperature on gelation behavior and thermal stability. Besides, the gelation mechanism and crosslinking density were elucidated in this work. A high-permeability sandstone core was used to test the plugging efficiency of this novel …

Silver Nanoparticle Surface Chemistry Determines Interactions With Human Serum Albumin And Cytotoxic Responses In Human Liver Cells, Kira M. Fahy, Madeline K. Eiken, Karl V. Baumgartner, Kaitlyn Q. Leung, Sarah E. Anderson, Erik Berggren, Evangelia Bouzos, Lauren R. Schmitt, Prashanth Asuri, Korin E. Wheeler

Chemistry and Biochemistry

Engineered nanomaterials (ENMs) are synthesized with a diversity of surface chemistries that mediate biochemical interactions and physiological response to the particles. In this work, silver engineered nanomaterials (AgENMs) are used to evaluate the role of surface charge in protein interactions and cellular cytotoxicity. The most abundant protein in blood, human serum albumin (HSA), was interacted with 40 nm AgENMs with a range of surface-charged coatings: positively charged branched polyethyleneimine (bPEI), negatively charged citrate (CIT), and circumneutral poly(ethylene glycol) (PEG). HSA adsorption to AgENMs was monitored by UV–vis spectroscopy and dynamic light scattering, while changes to the protein structure were evaluated …

Photophysical Characterization Of Isoguanine In A Prebiotic-Like Environment, Naishka E. Caldero-Rodríguez, Carlos E. Crespo-Hernández

Faculty Scholarship

It is intriguing how a mixture of organic molecules survived the prebiotic UV fluxes and evolved into the actual genetic building blocks. Scientists are trying to shed light on this issue by synthesizing nucleic acid monomers and their analogues under prebiotic Era-like conditions and by exploring their excited state dynamics. To further add to this important body of knowledge, this study discloses new insights into the photophysical properties of protonated isoguanine, an isomorph of guanine, using steady-state and femtosecond broadband transient absorption spectroscopies, and quantum mechanical calculations. Protonated isoguanine decays in ultrafast time scales following 292 nm excitation, consistently with …

Serendipitous Synthesis Of Cross-Conjugated Dienes By Cascade Deconstructive Esterification Of Thiomorpholinone-Tethered Alkenoic Acids, Abdikani Omar Farah, Jorge Garcia, Claire Borg, Timothy K. Beng

Student Published Works

Functionalized 1,3-dienes are ubiquitous structural motifs in biologically pertinent molecules. They are frequently employed as precursors for a broad range of chemical transformations, including Diels-Alder reactions. The stereoselective construction of highly decorated 1,3-dienes therefore represents an important research objective. Medicinal chemists are becoming increasingly interested in synthetic methodologies that not only achieve expedient construction and peripheral editing of heterocycles, but also seek to modify their core framework in order to achieve skeletal remodeling. In a succinct manifestation of this 'scaffold hopping' concept, we herein describe a cascade reaction, which converts thiomorpholinone-tethered alkenoic acids to 1,1-disubstituted amino-1,3-dienes. This domino process involves …

Essential Oils Composition And Biological Activity Of Chamaecyparis Obtusa, Chrysopogon Nigritanus And Lavandula Coronopifolia Grown Wild In Sudan, Loai M H Eltayeb, Sakina Yagi, Hanan M M Mohamed, Gokhan Zengin, Mohammad Ali Shariati, Maksim Rebezov, Abdullah Ibrahim Uba, Jose Manuel Lorenzo

College of Science & Mathematics Departmental Research

Generally, there are scant data about the constituents and eventually the biological activity of essential oils (EOs) from aromatic plants that grow naturally in Sudan. The present study aimed to determine the chemical composition, and antioxidant and enzyme inhibitory activities of EO extracted from the fruit of Chamaecyparis obtusa (Siebold and Zucc.) Endl. (family Cupressaceae), root of Chrysopogon nigritanus (Benth.) Veldkampis (family Poaceae) and aerial part of Lavandula coronopifolia Poir (family Lamiaceae). The fruit of C. obtusa contained only monoterpenes, mainly hydrogenated ones, with α-pinene (69.07%) as the major component. Oxygenated sesquiterpenes comprised the highest content of the C. nigritanus …

Biological Anolyte Regeneration System For Redox Flow Batteries, Olja Simoska, Zayn Rhodes, Emily Carroll, Katia N. Petrosky, Shelley D. Minteer

Chemistry Faculty Research & Creative Works

Redox flow battery (RFB) electrolyte degradation is a common failure mechanism in RFBs. We report an RFB using genetically engineered, phenazine-producing Escherichia coli to serve as an anolyte regeneration system capable of repairing the degraded/decomposed redox-active phenazines. This work represents a new strategy for improving the stability of RFB systems because, under the influence of genetically engineered microbes, the anolyte species does not display degradation after battery cycling.

Gas-Phase Formation And Spectroscopic Characterization Of The Disubstituted Cyclopropenylidenes C-C3(C2h)2, C-C3(Cn)2, And C-C3(C2h)(Cn), Athena R. Flint, Alexandria G. Watrous, Brent R. Westbrook, Dev J. Patel, Ryan C. Fortenberry

Faculty and Student Publications

Aims. The detection of c-C3HC2H and possible future detection of c-C3HCN provide new molecules for reaction chemistry in the dense ISM where R-C2 and R-CN species are prevalent. Determination of chemically viable c-C3HC2H and c-C3HCN derivatives and their prominent spectral features can accelerate potential astrophysical detection for this chemical family. This work will characterize three such derivatives: c-C3(C2H)2, c-C3(CN)2, and c-C3(C2H)(CN).

Methods. Interstellar reaction pathways of small carbonaceous species are well-replicated through quantum chemical means. Highly-accurate cc-pVX Z-F12/CCSD(T)-F12 (X =D,T) calculations generate the energetics of chemical formation pathways as well as the basis for quartic force field and …

Data Set For "Atmospheric Aging Of Combustion-Derived Particles: Impact On Stable Free Radical Concentration And Its Ability To Produce Reactive Oxygen Species In Aqueous Media", Brian Majestic, Heather L. Runberg

Chemistry and Biochemistry: Data Sets

Environmentally persistent free radicals (EPFR) are an emerging pollutant found in soot particles. Understanding how these change as they move through the atmosphere is important to human health. Here, soot was generated in the laboratory and exposed to simulated sunlight. The concentrations and characteristics of EPFR in the soot was recorded. Additionally, formation of hydroxyl radical from the photoactivated soot was measured.

The Effects Of Salinity And Acetaminophen On The Aquatic Snail Physa Acuta, Michelle Sackey-Ansah, Megan Mackey, Daniel Elias, Jason Doll, Alyssa Brookhart

Journal of the South Carolina Academy of Science

Pharmaceuticals are increasingly detected in water bodies, and their presence can negatively impact aquatic organisms. This effect can be amplified when combined with increasing salinity in freshwater ecosystems. Acetaminophen is a widely used analgesic that is commonly found in river, streams, and waters where it is discharged directly. Therefore, organisms present in these locations (e.g., insects, snails, amphibians, and fish) are likely to be affected by acetaminophen. In this study, we determined the effects of elevated salinity (0.68 g/L), acetaminophen (500 µg/L) and combined elevated salinity (0.68 g/L) and acetaminophen (500 µg/L), on the growth, reproduction, and movement of the …

Bitumen Aging—Laboratory Simulation Methods Used In Practice And Selected Directions Of Research On New Methods, Paweł Czajkowski, Andrzej Przyjazny, Grzegorz Boczkaj

Natural Sciences Publications

Changes in the properties of bitumen binders that occur as a result of aging have a huge impact on the durability of products produced from them. In particular, asphalt pavements, which constitute the most common use of petroleum bitumen, are susceptible to damage resulting from the increasing stiffness of the bitumen during its life cycle. Increased stiffness of asphalt pavements reduces the pavement resistance to low-temperature cracks and fatigue cracks, ultimately leading to the loss of their functional properties and the need for road repair. The rate of changes in bitumen properties is influenced by many factors, the most important …

The Water, Ji Kim

Open Educational Resources

Water is everywhere, thus, we tend to take it for granted. However, access to clean water has been inequitable; climate change is threatening the sea water level, causing the acidification of ocean water. In this project, we will investigate the environmental and social issues related to clean water and its impacts on our life by reading articles, watching videos, and exploring activities.

Development Of Battery Materials To Function As Corrosion Protection On Car Body Plates, Tubagus Noor Rohmannudin, Sulistijono Sulistijono, Noval Adrinanda, Faridz Wira Dharma, Samuel Areliano

Journal of Materials Exploration and Findings

Most car bodies made for mass production are made from steel or aluminum. Both are strong metals, but steel is cheaper than aluminum and is more commonly used in lower-end cars for a broader consumer range. The weakness of steel compared to aluminum is that it is susceptible to corrosion under certain conditions, and thus it may deteriorate over time without proper care. To prevent corrosion, modern cars are coated with paint to prevent direct contact with the environment. As a second line of protection, a car battery can be connected to the body to create an impressed current cathodic …

Potential Of Biduri Fiber (Calotropis Gigantea) As Material For Oil Spill Absorbent, Anne Sukmawati, Wulan Septiani

Journal of Materials Exploration and Findings

Biduri fiber (Calotropis gigantea) is a natural hollow fiber with hydrophobic and oleophilic properties potentially used as oil spilled sorbent from seawater. This study aims to determine the absorption capacity and efficiency of the Biduri fiber and membrane to fuel oil. Measurement of oil absorption to seawater was carried out at various fiber weights (0.5-1.5 g), fiber composition (50-95%), contact time (10-90 minutes), temperature (30 and 50°C), and compared with commercial products. The results showed that the fiber weight variation of 0.5-1.5 g has an average absorption efficiency of 96.67%, and the highest absorption was obtained in a weight of …

Dinitrogen Emissions Dominate Nitrogen Gas Emissions From Soils With Low Oxygen Availability In A Moist Tropical Forest, Maya Almaraz, Peter M. Groffman, Whendee L. Silver, Steven J. Hall, Yang Lin, Christine S. O'Connell, Stephen Porder

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Lowland tropical forest soils are relatively N rich and are the largest global source of N₂O (a powerful greenhouse gas) to the atmosphere. Despite the importance of tropical N cycling, there have been few direct measurements of N₂ (an inert gas that can serve as an alternate fate for N₂O) in tropical soils, limiting our ability to characterize N budgets, manage soils to reduce N₂O production, or predict the future role that N limitation to primary productivity will play in buffering against climate change. We collected soils from across macro- and micro-topographic gradients …

Influence Of Synthesis Conditions On The Physicochemical And Electrocatalytic Properties Of Non-Stoichiometric Ba2sr2la2ti4o12 Perovskites, Ofeliya Kostadinova, Iliyan Popov, Simeon M. Stankov, Hristo Kolev, Tamara Petkov

Karbala International Journal of Modern Science

Present work studies the influence of the pretreatment milling media (deionized water (BLTOS-H) and isopropanol (BLTOS-i)) on the surface characteristics, structure, chemical composition and catalytic activity of non-stoichiometric Ba2Sr2La2Ti4O12 perovskites. The IR spectroscopy and XRD analyses shows a difference in the structure and phase composition of the two materials. X-ray photoelectron spectroscopy detects a Ba2+- and La3+-enriched and Sr2+-depleted surface. The BLTOS-i sample appears to exhibit higher specific surface area (SSA) and pore volume in comparison to BLTOS-H. The electrochemical tests showed that BLTOS-H sample have similar behavior to platinum at current densi-ties up to 10 mA cm-2, while BLTOS-i …

The Boozi Device’S Effect On Aroma Compounds In Distilled Spirits, Drew Budner, Lindsey Bell, Katherine Thompson-Witrick

Journal of the South Carolina Academy of Science

The BooZi is a commercially available flavor-modifying device that claims to remove the negative flavor agents (congeners) from a number of different types of distilled spirits and wines. SPME was utilized for the extraction of the volatile and semi-volatile compounds within each sample. The analysis of the compounds found in the samples following exposure to the BooZi device were analyzed using a GC-MS. The most significant changes regarding the aroma profile of the distilled spirits were noticeable following 96 hours of exposure. The BooZi device was shown to be effective in reducing the concentration of a number of compounds, including …

Three-Stage Conversion Of Chemically Inert N-Heptane To Α-Hydrazino Aldehyde Based On Bioelectrocatalytic C-H Bond Oxyfunctionalization, N. Samali Weliwatte, Hui Chen, Tianhua Tang, Shelley D. Minteer

Chemistry Faculty Research & Creative Works

Simple petrochemical feedstocks are often the starting material for the synthesis of complex commodity and fine and specialty chemicals. Designing synthetic pathways for these complex and specific molecular structures with sufficient chemo-, regio-, enantio-, and diastereo-selectivity can expand the existing petrochemicals landscape. the two overarching challenges in designing such pathways are selective activation of chemically inert C-H bonds in hydrocarbons and systematic functionalization to synthesize complex structures. Multienzyme cascades are becoming a growing means of overcoming the first challenge. However, extending multienzyme cascade designs is restricted by the arsenal of enzymes currently at our disposal and the compatibility between specific …

Dual Ionic Liquid-Functionalized Cellulosic Materials: Thermal, Mechanical And Conductive Properties, Elizabeth Mcgrew, Kevin M. Miller Phd

Posters-at-the-Capitol

Cellulose, an inexpensive and renewable biomacromolecule, represents an intriguing synthetic foundation for new materials with task-specific properties. Here, we wish to report a synthetic route for functionalizing cellulose with a side chain containing two ionic liquid functional groups using azide-alkyne ‘click’ cyclization strategy, followed by quaternization of the two resulting heterocycles (1,2,3-triazole and imidazole). Through this functionalization strategy, the resulting cellulosic materials exhibited significant softening, with several glass transition (T_g) values observed below room temperature, indicating the amorphous nature of the materials, with the T_g dependent on both the length of the side chain and the …

Targeting Brd4 And Pi3k Signaling Pathways For The Treatment Of Medulloblastoma, Bharti Sethi, Virender Kumar, Thilina D. Jayasinghe, Yuxiang Dong, Donald R. Ronning, Haizhen Zhong, Donald W. Coulter, Ram I. Mahato

Chemistry Faculty Publications

Medulloblastoma (MB) is a malignant pediatric brain tumor which shows upregulation of MYC and sonic hedgehog (SHH) signaling. SHH inhibitors face acquired resistance, which is a major cause of relapse. Further, direct MYC oncogene inhibition is challenging, inhibition of MYC upstream insulin-like growth factor/ phosphatidylinositol-4,5-bisphosphate 3-kinase (IGF/PI3K) is a promising alternative. While PI3K inhibition activates resistance mechanisms, simultaneous inhibition of bromodomain-containing protein 4 (BRD4) and PI3K can overcome resistance. We synthesized a new molecule 8-(2,3-dihydrobenzo[b] [1, 4] dioxin-6-yl)-2-morpholino-4H-chromen-4-one (MDP5) that targets both BRD4 and PI3K pathways. We used X-ray crystal structures and a molecular modeling approach to confirm the interactions …

Strategies For Identifying Important Residues In The Trna Modification Protein Trm732, Alex K. Mullins, Natalie N. Creech, Holly Funk, Michael Guy

Posters-at-the-Capitol

Post-transcriptional tRNA modifications are required for efficient protein translation. In yeast, the Trm7 methyltransferase forms a complex with Trm732 to modify tRNA at position 32. In humans, lack of the human homolog for Trm7, FTSJ1, causes intellectual disability. Little is known about the function of Trm732, although we have shown that one conserved motif in Trm732 is important for tRNA modification. We have identified other residues important for function using two strategies. First, we compared Trm732 proteins of different organisms using protein alignments to determine conserved regions to mutate for testing. We have generated four new Trm732 variants and have …