Chemistry Commons^™

Optimization Of The Starch Chitosan-Based Flocculant Crosslinked By Ethylene Glycol Dimethacrylate On Removing Dypro 19 Textile Dye From Wastewater, Asep Nurohmat Majalis, Putri Ramadhani, Hendris Hendarsyah Kurniawan, Axel Dimaz Sanusi Pasaribu, Hafiizh Prasetia, Fitri Yuliani, Andreas Andreas, Hartati Hartati

Karbala International Journal of Modern Science

Dyes used in industry, especially textile dyes, are one of the water pollutants that receive much attention because they are potentially toxic, carcinogenic, mutagenic, and generally challenging to decompose naturally. Textile dyes from wastewater can be removed through coagulation-flocculation. However, conventional coagulation-flocculation based on Fe and Al salts and synthetic polymers often leaves residual pollution. In this research, the performance of the new biopolymer-based flocculant, namely starch-ethylene glycol dimetacrylate-chitosan (SEC), which can act as coagulants and flocculants in solid-liquid separation of textile dyes, has been optimized using response surface methodology (RSM) approach. The influences of several independent variables, such …

Breast Cancer Area Identification In Mammograms Using Expectation Maximization Gaussian Mixture Model, Rizki Khoirun Nisa, Dian Kurniasari, Favorisen R. Lumbanraja, Warsono Warsono

Karbala International Journal of Modern Science

Breast cancer accounts for 25% of all cancer diagnoses and 16% of cancer-related deaths among women globally, with high mortality rates due to late diagnosis. Early detection relies on imaging techniques such as mammography, histopathology, and breast ultrasound, with mammography being the gold standard due to its proven to detect breast cancer, thus it is effective for breast cancer treatment. However, mammogram images often produce noise and artefacts, complicating early-stage cancer detection and emphasizing the need for advanced image processing. Clustering algorithms such as K-means and Expectation Maximization - Gaussian Mixture Model (EM-GMM) have shown potential in image segmentation. This …

Interactions Of The Sars-Cov-2 Viral Genome 3’-Untranslated Region With Viral And Host Rnas, Caleb Frye, Mihaela Rita Mihailescu

Electronic Theses and Dissertations

This dissertation focuses on the characterization of RNA-RNA interactions within the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) genome and with host microRNAs. As the causative agent of coronavirus disease 2019 (COVID-19), SARS-CoV-2 has evolved rapidly since its appearance. This has warranted prompt characterization of the virus particularly of its single stranded RNA (ssRNA) genome. By using a combination of bioinformatics, biophysics, and/or biological assays, we analyzed the SARS-CoV-2 viral genomic RNA and uncovered interactions of genomic RNA with host RNAs, highlighting an underutilized method of targeting RNA viruses. We showed here that the conserved elements in the viral genomic …

Molten Flux Synthesis Of Plutonium (Iv) Silicates K2Pusi2O7 And Rb2Pusi6O15, Travis K. Deason, Gregory Morrison, Amir Mofrad, Jake Amoroso, David Diprete, Theodore M. Besmann, Shanna L. Estes, Hans Conrad Zur Loye

Faculty Publications

Few plutonium containing silicates have been reported in the literature and only one other tetravalent plutonium silicate structure has been reported using the flux growth method. With the goal of understanding actinide incorporation into silicates, we describe herein two new plutonium (IV) silicates, Rb2PuSi6O15 and K2PuSi2O7, synthesized using a mixed alkali chloride/alkali fluoride flux growth. Both structures crystallize in the C2/c space group with lattice parameters a=24.2980(10) Å, b=7.1466(3) Å, c=17.2025(8) Å and 96.6560(10)° for Rb2PuSi6O15, and a=9.9478(2) Å, b=5.59820 (10) Å, c=13.1848(2) Å, and 105.7400(10)° for K2PuSi2O7. Comparisons to the synthesis of other reported alkali actinide silicates (Ce, U, …

Intrinsic Gas-Phase Behavior Of Uranium Species: A Comprehensive Reactivity Study Of [O=U≡Ch]+ And [Uh]+, Justin Terhorst

Electronic Theses and Dissertations

The intrinsic chemistry of actinide elements, particularly uranium, remains a key challenge in understanding f-block reactivity due to the complexity introduced by solvent interactions, counter-ions, and complex equilibria in the condensed phase. In this dissertation, a systematic gas-phase study utilizing preparative tandem ion-trap mass spectrometry (PTMSⁿ) is presented, focusing on the reactivity of uranium-centered species, specifically [OUCH]⁺, an oxy uranium methylidyne species, and [UH]⁺ ions. By stripping away solvent effects and isolating the ions, PTMSⁿ provides a powerful platform to probe the fundamental chemical behavior of uranium species in their intrinsic state.

The …

Development Of Methods For Predicting Second Harmonic Generation (Shg) Responses Of New Infrared Nonlinear Optical (Ir-Nlo) Materials, Katherine Colbaugh

Electronic Theses and Dissertations

Dissertation supervised by Dr. Jennifer A. Aitken.

In this work, calculations-based methods were evaluated for use in prediction of second harmonic generation (SHG), specifically χ⁽²⁾ values, of infrared nonlinear optical (IR-NLO) materials. Net dipole moment and dipole moment per volume were calculated by the bond valence sum method. Average F-index, proposed in this research, and group F-index, both representing induced dipole moment were also calculated. Each calculation was evaluated by comparing the results to single crystal and powder χ⁽²⁾ measurements of IR-NLO materials. The selected dataset consisted of ninety-six compounds including polar and nonpolar structures, newly discovered and …

Rna Structural-Dynamical Hierarchy: Sars-Cov, Sars-Cov-2, And Delta/Omicron Variant S2m Monomers, Kissing Complexes, And Extended Duplexes, Adam Kensinger

Electronic Theses and Dissertations

The power and promise of ribonucleic acid (RNA) molecules are only beginning to be realized in living organisms and pharmaceutical intervention. Specifically, defining the chemical physics of RNA’s heterogenous structural ensemble and dynamics, which has experienced expansive growth over the last few years, is central to a complete understanding, yet continues to be a significant challenge. A 41-nucleotide hairpin called the stem-loop II motif (s2m), present in the viral genomes of severe acute respiratory syndrome (SARS), SARS-coronavirus-2 (SARS-CoV-2), and the Delta and Omicron variants responsible for the COVID-19 pandemic, is a potential antiviral target due to its high sequence conservation …

Assembly Of Ppsu-Oligomers, Mariam Nesterov

Student Theses and Dissertations

The development of nanostructures for delivering multiple proteins to targeted antibodies has become a promising avenue in biotechnology, driven by advancements in synthetic polymers like poly(propylene sulfone), PPSU. However, the PPSU polymer faces a major limitation - its high insolubility. To address this challenge, this study investigates whether PPSU oligomers can enhance both the solubility and stability of lysozyme, a model protein that is cost-effective and widely accessible. Using dimer, trimer, tetramer, and hexamer configurations, we analyzed the interactions between PPSU oligomer and lysozyme under varying conditions. Our results show that the dimer and trimer are water soluble (no aggregate …

Synthetic Studies On Ship Activators And New Oxidative Methods Utilizing Ddq And Hypervalent Iodine Catalysts, Christos Nixarlidis

Dissertations - ALL

One important cell signaling pathway is the PI3K pathway because it influences many key cellular functions such as proliferation and apoptosis. Among the enzymes that are involved in this pathway, the SH2-containing inositol-5’-phosphatase (SHIP) plays an important role by maintaining the balance of PI(3,4,5)P3 and PI(3,4)P2. SHIP activation promotes a higher rate of hydrolysis of PI(3,4,5)P3 and thus reduces the downstream activation of AKT, which influences many cell processes. Activation of SHIP using small molecules may be useful for certain diseases such as inflammatory disorders and some types of cancer. The synthesis and evaluation of a new class of sulfonamide …

Modulating Liquid-Liquid Phase Separation Of Intrinsically Disordered Proteins Through Lipidation, Zhe Zhang

Dissertations - ALL

Liquid-liquid phase separation (LLPS) is a fascinating biological phenomenon that enables cells to form membraneless organelles, creating specialized compartments for orchestrating complex biochemical reactions. While significant progress has been made in deciphering the sequence determinants underlying phase separation, precisely modulating these features remains a challenge. Inspired by biology, post-translational modifications (PTMs) offer a promising approach to modulate the protein condensates formation and their properties in real-time, without altering the sequences. Despite the identification of over 300 types of PTMs, most research has predominantly focused on charge-altering modifications. The effects of non-charged PTMs, such as lipidation, on LLPS remain poorly understood. …

An In-Depth Analysis And Comparison Of Eco And Non-Eco Surfboard Waxes, Markos Kaskaneas - Efthymiou

The Plymouth Student Scientist

Questions regarding the sustainability of petroleum-based surfboard waxes gave rise to the development and marketing of a sustainable alternative called “Eco” surf wax. The chemistry behind surf waxes is generally unknown and there is no published research on the area of surf waxes. In this analysis, the chemical properties of both types of waxes were investigated, to determine the difference between non-eco and eco waxes and between different water temperature rating waxes. 15 surf wax samples (10 non-eco, 5 eco) were extracted into organic and inorganic fractions and analysed by FT-IR, GC-MS, and HTGC-FID/MS. Multivariate statistical analysis was also performed. …

Developing A Method To Identify Tyre Particles By Detecting Benzothiazole Via Gc-Ms, Emma Paull

The Plymouth Student Scientist

Tyre particles are a dominant source of microplastic pollution in our environment. However, their chemical and physical properties are poorly understood and no standardised methods for identifying and quantifying them exist. This study looked to develop a method to identify tyre particles using two tyre samples of differing particle sizes, fine (62 - 125 µm) and coarse (250 – 500 µm). Both samples underwent ultrasound-assisted extraction before being analysed via gas chromatography-mass spectrometry (GC-MS) in both full scan and SIM mode, using benzothiazole as a marker. Both samples were also analysed via particle size analysis, scanning electron microscopy (SEM) and …

Synthesis And Characterisation Of An Acetylcholinesterase Inhibitor, Elijah Rahman-Riding

The Plymouth Student Scientist

Acetylcholinesterase (AChE) inhibitors are currently the only effective treatment for people with Alzheimer’s disease (AD), a fatal neurodegenerative disease that affects 50 million people worldwide at present but is expected to rise dramatically over the next 30 years. The aim of this research was to synthesise an AChE inhibitor derivative of tacrine, 4-chloro-2(((1,2,3,4-tetrahydroacridin-9yl)imino)methyl)phenol (chlorophenol tacrine). This was achieved by first synthesising tacrine, evidencing successful synthesis and assaying purity of the product, then, synthesising a simple derivative, acetyl tacrine, before chlorophenol tacrine. At every stage of the investigation comprehensive structural analysis of each product was obtained using FT-IR, CHN analysis, GC-FID, …

Application Of Two-Directional Carbonyl Ene Reaction To The Synthesis Of Complex Tetrahydropyrans, And Studies Toward The Synthesis Of C26-C39 Subunit Of Spirastrellolide B., Md Abid Abid Hasan

Dissertations - ALL

The use of exocyclic enol ethers as nucleophiles in carbon-carbon bond forming reactions has been underutilized in organic synthesis. This work describes the use of 6-iodomethyl-2-methylenetetrahydropyran as a bis-exocyclic enol ether equivalent for the synthesis of pyran derivatives. Use of this linchpin allows for bidirectional elaboration of the pyran core by two directional carbonyl ene. The development of a convergent, modular synthesis of 2,6-disubstituted-4H-pyrans in a three-step sequence starting from 6-iodomethyl-2-methylenetetrahydropyran is described. Initial carbonyl ene reaction of 6-iodomethyl-2-methylenetetrahydropyran with aldehydes or activated ketones was followed by elimination of iodide to give cross oriented bis-enol ethers that contain both endocyclic …

Studies Towards The Synthesis Of A Simplified Forskolin Core And Phomactin A, Fortune Ononiwu

Dissertations - ALL

Oxadecalins are privileged scaffolds found in various natural products that show biological activity, such as platelet aggregating factor antagonism and activation of adenyl cyclase. As such, various synthetic methods such as intramolecular substitution reactions and [4+2] cycloadditions have been developed for the construction of these important intermediates. Studies towards the synthesis of a simplified core of the labdane diterpene, forskolin, are described. Forskolin is the only known supplement to naturally raise cAMP levels, thereby displaying important pharmacological properties. The synthetic route described features a Lewis acid catalyzed dihydropyrone Diels-Alder reaction for rapidly assembly of the ABC tricycle. Modified Saegusa-Ito oxidation …

Peptides And Metalloproteins: Evolution, Catalysis And Material Design, Dona Imanga Upamadi Edirisinghe

Dissertations - ALL

Peptide hydrogels are an important class of biomaterials that have gained significant attention in recent years. The stimuli responsive materials change their properties in response to pH, redox, temperature and enzymes and this property allowed us to design the materials with tunable properties based on their end application. This dissertation reports the de novo design, synthesis and characterization of short chain peptide sequences and optimizations of those in order to develop them into potential candidates in wound care and drug delivery applications. The investigation of these novel peptide sequences will open up new possibilities to tailor the properties through simple …

Synthesis, Characterization, And Investigation Of Photochemical And In Vitro Properties Of Novel Zn(Ii) Phthalocyanine, Yasemi̇n Bayğu Yildiz, Ni̇lgün Kabay, Burak Yildiz, İpek Ömeroğlu, Mahmut Durmuş, E. Riza Karagür, Hakan Akça, Çağri Ergi̇n, Yaşar Gök

Turkish Journal of Chemistry

In our work, a new non-peripheral zinc(II) phthalocyanine bearing octa carboxylic acid ethyl ester derivative substituted triazole attached propylmercaptothiobenzylmercapto derivative was synthesized by the tetramerization reaction of phthalonitrile. The photochemical in vitro photodynamic activity of zinc(II) phthalocyanine (ZnPc-I), such as human non-small cell lung carcinoma cell lines, was investigated in this study. The singlet oxygen generation property of novel zinc(II) phthalocyanine (ZnPc-I) was also examined due to the significantly high singlet oxygen quantum yield of ZnPc-I (ΦΔ = 0.66). The antiproliferative effects of ZnPc-I were also investigated on A549 and H1299 cell lines, our results demonstrate that the ZnPc-I has …

A Fast And Responsive Turn-On Fluorescent Probe Based On A Quinone Conjugated Alkoxy Derivative For Biothiols And A Cellular Imaging Study, Ulviyye Nemetova, Ayşe Nur Önem, Alev Er, Sefa Çeli̇k, Ayşen E. Özel, Sevi̇m Akyüz, Mustafa Özyürek, Si̇bel Şahi̇nler Ayla

Turkish Journal of Chemistry

Detection of intracellular biothiols (cysteine (CYS), N-acetyl cysteine (NAC) and glutathione (GSH)) with high-selectivity and sensitivity is important to reveal biological functions. In this study, 2-(2-methoxy-4-methylphenoxy)-3-chloro-5,8-dihydroxynaphthalene-1,4-dione (3) (DDN-O) compound was newly synthesized and used as a fluorogenic probe (detector molecule) in the fluorometric method for the rapid, highly selective and sensitive determination of biothiols. The intensity values (λex = 260 nm, λem = 620 nm) of the product were measured by adding biotihols to the reaction medium at varying concentrations and the glutathione equivalent thiol content (GETC) values of each biotiol were calculated. Using the compoud (3), the reference biotiol …

Understanding Ammonia's Role In Mitigating Concentration Polarization In Anion-Exchange Membrane Electrodialysis, Abdallah Timmaoui, Mahmoud Ferhat, Nesri̇ne Souad Ferhat, Ahmed Hamdi

Turkish Journal of Chemistry

In processes such as electrodialysis, the applied electrical potential is constrained by concentration polarization at the membrane/solution interface. This polarization, which intensifies at higher current densities, impedes ion transport efficiency and may lead to problems such as salt precipitation, membrane degradation, and increased energy consumption. Therefore, understanding concentration polarization is essential for enhancing membrane performance, improving efficiency, and reducing operational costs. This study investigates the impact of ammonia buffer (NH₄⁺/NH₃) on sulfate ion transport through anion-exchange membranes, with a particular focus on limiting current density and concentration polarization under constant current conditions. Our findings demonstrate that ammonia effectively eliminates concentration …

New Naphthalene-Linked Pyrazoline-Thiazole Hybrids As Prominent Antilung And Antibreast Cancer Inhibitors, Hali̇li̇brahi̇m Çi̇ftçi̇, Masami Otsuka, Mikako Fujita, Belgi̇n Sever

Turkish Journal of Chemistry

Epidermal growth factor receptor (EGFR) and HER2, pioneer members of the receptor tyrosine kinase subfamily, are frequently mutated and/or overexpressed in several types of human cancers, including non-small cell lung cancer (NSCLC) and breast cancer, which are leading causes of cancer-related deaths worldwide. EGFR and HER2-focused anti-NSCLC and anti-breast cancer studies encouraged us to search for new potential agents. For this purpose, in the current work, naphthalene-linked pyrazoline-thiazole hybrids (BTT1-10 and BTP1-10) were synthesized and examined for their antiproliferative effects on A549 NSCLC and MCF-7 breast cancer cell lines. According to the results, MTT assay showed that BTT-5 induced strong …

Analysis And Optimization Of The Adsorption Of Lead Ions On A New Material Based On Silica Synthesized From Blast Furnace Slag, Toufik Chouchane, Ouahida Khireddine, Sabiha Chouchane, Mohamed Tayeb Abedghars, Hazem Meradi

Turkish Journal of Chemistry

A novel silica-based material (SBM), synthesized from chemically, thermally, and mechanically treated blast furnace slag (TBFS), was examined for its batch-mode lead adsorption capacity, based on various parameters. Physico-chemical examinations revealed that the formulation of the new material (SBM) consists mainly of silica, which represents 81.79% of its total composition. After modification, the measured specific surface area changed significantly, from 275.8 to 480.13 m2/g, with a point of zero charge (PZC) of approximately 3.4 on the pH scale. The experiment revealed that the driving factors (contact time, stirring speed, solution pH, temperature, and initial concentration) greatly influenced the improvement of …

Preparation Of Manganese-Doped Carbon Quantum Dots@Halloysite Nanotubes Composites Films For Advanced Uv Shielding Properties, Xiao Zhang, Bin Wang

Turkish Journal of Chemistry

The development of Ultraviolet (UV) shielding materials are of great importance to protect human's health concerns and prevent the degradation of organic matters. However, the synthesis of highly efficient UV shielding polymer nanocomposites is currently limited by the agglomeration of inorganic anti-UV nanoparticles (NPs) within the polymer matrix and limited absorption spectrum of UV shielding agents. In this study, highly effective manganese doped carbon quantum dots@halloysite nanotubes composites (Mn-CDs@HNTs/PAS) were successfully synthesized by loading manganese doped carbon quantum dot (Mn-CDs) into UV shielding effective halloysite nanotubes (HNTs) via solvothermal method, followed by polymerization modification. The results show that inorganic NPs …

Synthesis, Structure, Hirshfeld Surface Analysis, And Molecular Docking Studies Of The Cocrystal Between The Cu(Ii) Complex Of Salicylic Acid And Uncoordinated Piracetam, Nazokat N. Yuldasheva, Ikram I. Abdullaev, Oybek I. Khudoyberganov, Lola A. Gandjaeva, Pirnazar K. Kodamboev, Elyor Sh. Samandarov, Adkhamjon S. Normamatov, Abror Kh. Ruzmetov, Yuldosh Y. Yakubov, C. Balakrishnan, Bakhtiyar T. Ibragimov, Aziz Bakhti̇yarovich Ibragimov

Turkish Journal of Chemistry

The cocrystal or supramolecular complex between Cu(II) complex of salicylic acid and uncoordinated piracetam has been synthesized. Its structure is characterized by element analysis, FT-IR, UV-Visible spectroscopy and X-ray crystallography. Spectroscopic methods confirm the formation of the metal complex while X-ray crystallography establishes molecular and crystal structure of the obtained compound. Binuclear Cu(II) complex of salicylic acid (complex molecule) is in the form of “Chinese lantern” and it interacts with uncoordinated piracetam by complicated system of H-bonds. However, according to the Hirshfeld surface analysis a contribution of the O•••H/H•••O contacts is only 24.9% while H•••H and H•••C/C•••H contacts account for …

Capacity-Weighted Figures-Of-Merit For Battery Transport Metrics, Cj Sturgill, Christopher Sutton, Julian Schwenzel, Morgan Stefik

Faculty Publications

New battery materials with improved transport are needed. Typical measurements yield widely varying voltage-dependent diffusivities and reporting practices are diverse. Some materials (e.g. first-order phase change) have most redox occur at a specific voltage and may be sufficiently represented by singular transport metrics. Many rapid intercalation materials, however, exhibit second-order phase transitions with redox over a broad voltage range. How should such cases be compared? The use of capacity-weighted average values is suggested where voltage-dependent metrics are consolidated into representative descriptors as figures-of-merit. Examples are elaborated where differential capacity (dQ/dV) is used to derive a …

Synthesis Of Higher-Order Catenanes And Catenane-Based Materials, Gray Harlan

Arts & Sciences Graduate Student Theses and Dissertations

Catenanes are a subset of mechanically interlocked molecules (MIMs) and are composed of interlocked rings that can be oriented linearly, radially, or branched. A defining feature of all MIMs is that they are bound through their architectures consisting of mechanical bonds, leading to unique topologies. Catenanes have attracted interest due to their stimuli-responsive behavior and the degrees of freedom afforded by the mechanical bond, a feature which is absent with standard covalent bonds. The stimuli responsiveness of catenanes arises from their templated syntheses, where two or more pre-macrocycles are brought together by a driving force. Various templation strategies rely on …

Brain Endothelial Permeability, Transport, And Flow Assessed Over 10 Orders Of Magnitude Using The In Situ Brain Perfusion Technique, Quentin R. Smith, Haritha Mandula, Jagan Mohan R. Parepally, Jun Oki, Fancy Thomas, Helen R. Thorsheim, Abraham J. Al‑Ahmad, Thomas J. Abbruscato, Per Ask, David S. Hage, Peter J. Robinson

David Hage Publications

Background Cerebral blood flow normally places a limit on the magnitude of brain vascular permeability (P) that can be measured in vivo. At normal cerebral blood flow, this limit falls at the lower end of lipophilicity for most FDAapproved CNS drugs. In this study, we report on two methods that can be used to overcome this limitation and measure brain vascular permeability values that are up to ~1000 times higher using the in situ brain perfusion technique.

Methods Rat brain was perfused with physiological saline at increased flow rate and in the presence of various concentrations of plasma protein, serum …

Analysis Of Dense Metals Accumulation In Shikaripara Stone Mines, Gopinath Gorai, Nirajan Kumar Mandal

Makara Journal of Science

This study aimed to measure the amount of dangerous substances in the cultivated area of the Shikaripara stone mines in Jharkhand, India, which are well known for their stone quarrying. Sixteen soil samples were collected at varying dis-tances from the Shikaripara stone mines in the Dumka District of Jharkhand. The metals found in these samples in-clude Pb, As, Zn, Mn, Cd, Cu, Fg, and Fe. The combined amount of the elements was calculated by inductively coupled plasma mass spectrometry. Enrichment factor, accumulation index, contamination factor, pollution load index (PLI), Nemerow index, and ecological risk index (RI) were employed to assess …

Vibrational And Electronic Spectroscopy Of 2-Cyanoindene Cations, Thomas E. Douglas-Walker, Eleanor K. Ashworth, Mark H. Stockett, Francis C. Daly, Isabelle Chambrier, Vincent J. Esposito, Marius Gerlach, Angel Zheng, Julianna Palotás, Andrew N. Cammidge, Ewen K. Campbell, Sandra BrüNken, James N. Bull

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

2-Cyanoindene is one of the few specific aromatic or polycyclic aromatic hydrocarbon (PAH) molecules positively identified in Taurus molecular cloud-1 (TMC-1), a cold, dense molecular cloud that is considered the nearest star-forming region to Earth. We report cryogenic mid-infrared (550–3200 cm^–1) and visible (16,500–20,000 cm^–1, over the D2 ← D0 electronic transition) spectra of 2-cyanoindene radical cations (2CNI⁺), measured using messenger tagging (He and Ne) photodissociation spectroscopy. The infrared spectra reveal the prominence of anharmonic couplings, particularly over the fingerprint region. There is a strong CN-stretching mode at 2177 ± 1 cm^–1 (4.593 …

Utility Of Immobilized Metal Salens As Electrocatalysts: Fuel Cells And Organic Electrosynthesis, Zachary A. Nguyen, Shelley D. Minteer

Chemistry Faculty Research & Creative Works

There have been significant advancements in the electrosynthesis of fuels and organic molecules, making it an increasingly sustainable and cost-effective alternative to traditional chemical redox reagents. Early versions of these systems faced challenges in chemo selectivity due to high applied overpotentials, which have been mitigated with the introduction of molecular electrocatalysts, like metal salens (MSalens). These MSalens reduce the required overpotentials, increase turnover numbers (TON), and have simple modularity within their ligand structure allowing for tunable selectivity. While these MSalen electrocatalysts are typically used homogeneously for engineering simplicity, downstream separations are often costly and time-consuming. Immobilization of MSalens addresses these …

Organic Alkalinity Distributions, Characteristics, And Application To Carbonate System Calculations In Estuarine And Coastal Systems, Christopher W. Hunt, Joseph Salisbury, Xuewu Liu, Robert H. Byrne

Faculty Publications

The capacity of aquatic systems to buffer acidification depends on the sum contributions of various chemical species to total alkalinity (TA). Major TA contributors are inorganic, with carbonate and bicarbonate considered the most important. However, growing evidence shows that many rivers, estuaries, and coastal waters contain dissolved organic molecules with charge sites that create organic alkalinity (OrgAlk). This study describes the first comparison of (1) OrgAlk distributions and (2) acid–base properties in contrasting estuary-plume systems: the Pleasant (Maine, USA) and the St. John (New Brunswick, CA). The substantial concentrations of OrgAlk in each estuary were sometimes not conservative with salinity …