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Articles 5491 - 5520 of 33150

Full-Text Articles in Chemistry

Growth Kinetics Determine The Polydispersity And Size Of Pbs And Pbse Nanocrystals, Michael P. Campos, Jonathan De Roo, Matthew W. Greenberg, Brandon M. Mcmurtry, Mark P. Hendricks, Ellie Bennett, Natalie Saenz, Matthew Y. Sfeir, Benjamin Abecassis, Sanjit K. Ghose, Jonathan S. Owen Mar 2022

Growth Kinetics Determine The Polydispersity And Size Of Pbs And Pbse Nanocrystals, Michael P. Campos, Jonathan De Roo, Matthew W. Greenberg, Brandon M. Mcmurtry, Mark P. Hendricks, Ellie Bennett, Natalie Saenz, Matthew Y. Sfeir, Benjamin Abecassis, Sanjit K. Ghose, Jonathan S. Owen

Advanced Science Research Center

A library of thio- and selenourea derivatives is used to adjust the kinetics of PbE (E = S, Se) nanocrystal formation across a 1000-fold range (kr = 10−1 to 10−4 s−1), at several temperatures (80–120 °C), under a standard set of conditions (Pb : E = 1.2 : 1, [Pb(oleate)2] = 10.8 mM, [chalcogenourea] = 9.0 mM). An induction delay (tind) is observed prior to the onset of nanocrystal absorption during which PbE solute is observed using in situ X-ray total scattering. Density functional theory models fit to the X-ray pair distribution function (PDF) support a Pb2(μ2-S)2(Pb(O2CR)2)2 structure. Absorption spectra …


Developing Efficient Transition Metal Catalyzed C-C & C-X Bond Construction, Chiyu Wei Mar 2022

Developing Efficient Transition Metal Catalyzed C-C & C-X Bond Construction, Chiyu Wei

USF Tampa Graduate Theses and Dissertations

This dissertation mainly contains three parts: 1) The synergistic Pd/enamine catalysis for asymmetric hydrocarbon functionalization of unactivated alkenes with ketones; 2) Gold redox catalysis with a selenium cation as mild oxidant; 3) HFIP promoted disulfidation and diselenation of alkyne, alkene, and allene.

Palladium-catalyzed alkene activation has its intrinsic limitation: 1) the requirement of a pre-functionalized alkene to form a Pd π-allyl complex; 2) problematic reversible β-H elimination. It always leads to limited reaction scope and losing of the stereochemical control. Synergistic palladium and enamine catalysis was conducted to promote ketone addition to unactivated olefins. A secondary amine-based organocatalyst was identified …


Arsenic In Groundwater Sources From Selected Communities Surrounding Taal Volcano, Philippines: An Exploratory Study, Geminn Louis C. Apostol, Sary Valenzuela, Xerxes Seposo Mar 2022

Arsenic In Groundwater Sources From Selected Communities Surrounding Taal Volcano, Philippines: An Exploratory Study, Geminn Louis C. Apostol, Sary Valenzuela, Xerxes Seposo

Ateneo School of Medicine and Public Health Publications

Arsenic (As) is a highly toxic, carcinogenic trace metal that can potentially contaminate groundwater sources in volcanic regions. This study provides the first comparative documentation of As concentrations in groundwater in a volcano-sedimentary region in the Philippines. Matched, repeated As measurements and physico-chemical analyses were performed in 26 individual wells from 11 municipalities and city in Batangas province from July 2020 to November 2021. Using the electrothermal atomic absorption spectrometric method, analysis of the wells revealed that in 2020, 23 out of 26 (88.46%) had As levels above the WHO limit of >10 ppb while 20 out of 26 wells …


Repurposing Lansoprazole And Posaconazole To Treat Leishmaniasis: Integration Of In Vitro Testing, Pharmacological Corroboration, And Mechanisms Of Action, Yash Gupta, Steven Goicoechea, Jesus G. Romero, Raman Mathur, Thomas R. Caulfield, Daniel P. Becker, Ravi Durvasula, Prakasha Kempaiah Mar 2022

Repurposing Lansoprazole And Posaconazole To Treat Leishmaniasis: Integration Of In Vitro Testing, Pharmacological Corroboration, And Mechanisms Of Action, Yash Gupta, Steven Goicoechea, Jesus G. Romero, Raman Mathur, Thomas R. Caulfield, Daniel P. Becker, Ravi Durvasula, Prakasha Kempaiah

Chemistry: Faculty Publications and Other Works

Leishmaniasis remains a serious public health problem in many tropical regions of the world. Among neglected tropical diseases, the mortality rate of leishmaniasis is second only to malaria. All currently approved therapeutics have toxic side effects and face rapidly increasing resistance. To identify existing drugs with antileishmanial activity and predict the mechanism of action, we designed a drug-discovery pipeline utilizing both in-silico and in-vitro methods. First, we screened compounds from the Selleckchem Bio-Active Compound Library containing ~1622 FDA-approved drugs and narrowed these down to 96 candidates based on data mining for possible anti-parasitic properties. Next, we completed preliminary in-vitro testing …


Determination Of Optical Density (Od) Of Oligodeoxynucleotide From Hplc Peak Area, Komal Chillar, Yipeng Yin, Dhananjani Eriyagama, Shiyue Fang Mar 2022

Determination Of Optical Density (Od) Of Oligodeoxynucleotide From Hplc Peak Area, Komal Chillar, Yipeng Yin, Dhananjani Eriyagama, Shiyue Fang

Michigan Tech Publications, Part 1

Oligodeoxynucleotides (ODNs) are typically purified and analysed with HPLC equipped with a UV-Vis detector. Quantities of ODNs are usually determined using a UV-Vis spectrometer separately after HPLC, and are reported as optical density at 260 nm (OD260). Here, we describe a method for direct determination of OD260 of ODNs using the area of the peaks in HPLC profiles.


Computational Study Of The Reactions Of Heteroatomic Compounds On Ceo2, Suman Bhasker Ranganath Mar 2022

Computational Study Of The Reactions Of Heteroatomic Compounds On Ceo2, Suman Bhasker Ranganath

LSU Doctoral Dissertations

The mechanisms of ambient-temperature reactions of heteroatomic compounds catalyzed by ceria (CeO2), an archetypical reducible oxide, for enzyme mimetics, environmental protection, and chemical synthesis are investigated in this dissertation using theoretical methods. CeO2 is modeled with thermodynamically stable low-index surfaces exposed by commonly studied ceria thin films and nano particles. To understand phosphatase-like dephosphorylation activity, stable adsorption states and surface reactions of model phosphates are examined. Binding of the central P-atom to surface lattice oxygen (Olatt) supplemented by phosphoryl O-Ce interaction is the only stable adsorption state for the un-dissociated molecule. Deprotonation of phosphate monoesters, …


Kinetics, Characterization, And Applications In The Development Of Next-Generation Cure-On-Demand Polymeric Materials Through Frontal Polymerization, Daniel Paul Gary Mar 2022

Kinetics, Characterization, And Applications In The Development Of Next-Generation Cure-On-Demand Polymeric Materials Through Frontal Polymerization, Daniel Paul Gary

LSU Doctoral Dissertations

Frontal polymerization (FP) is a process in which a front propagates in a localized reaction zone converting monomer into polymer. This work explored the kinetics and applications of FP for the development of cure-on-demand materials.

The kinetic effects of fillers on frontal polymerization have not been thoroughly explored. In Chapter 2, various fillers were used, and their effects on front velocity and front temperature were determined. Clay minerals are primarily used, but the thermal conductive effects of milled carbon fiber were also explored. It was found that some fillers inhibit frontal polymerization through radical scavenging, while others increased the front …


The Phase Diagram Of A Non-Ideal Mixture’S P − V − X 2-Component Gas=Liquid Representation, Including Azeotropes, Carl W. David Mar 2022

The Phase Diagram Of A Non-Ideal Mixture’S P − V − X 2-Component Gas=Liquid Representation, Including Azeotropes, Carl W. David

Chemistry Education Materials

The liquid=vapor two phase p−v−x diagram is constructed for non-ideal solutions including azeotropes.


One Planet: One Health. A Call To Support The Initiative On A Global Science-Policy Body On Chemicals And Waste, Werner Brack, Damia Barcelo Culleres, Alistair B.A. Boxall, Helene Budzinski, Sara Castiglioni, Adrian Covaci, Valeria Dulio, Beate I. Escher, Peter Fantke, Faith Kandie, Despo Fatta-Kassinos, Felix J. Hernandez, Klara Hilscherova, Juliane Hollender, Henner Hollert, Annika Jahnke, Barbara Kasprzyk-Hordern, Stuart J. Khan, Andreas Kortenkamp, Klaus Kuemmerer, Brice Lalonde, Marja H. Lamoree, Yves Levi, Pablo Antonio Lara Martin, Cassiana C. Montagner, Christian Mougin, Titus Msagati, Joerg Oehlmann, Leo Posthuma, Malcolm Reid, Martin Reinhard, Susan D. Richardson, Et. Al. Mar 2022

One Planet: One Health. A Call To Support The Initiative On A Global Science-Policy Body On Chemicals And Waste, Werner Brack, Damia Barcelo Culleres, Alistair B.A. Boxall, Helene Budzinski, Sara Castiglioni, Adrian Covaci, Valeria Dulio, Beate I. Escher, Peter Fantke, Faith Kandie, Despo Fatta-Kassinos, Felix J. Hernandez, Klara Hilscherova, Juliane Hollender, Henner Hollert, Annika Jahnke, Barbara Kasprzyk-Hordern, Stuart J. Khan, Andreas Kortenkamp, Klaus Kuemmerer, Brice Lalonde, Marja H. Lamoree, Yves Levi, Pablo Antonio Lara Martin, Cassiana C. Montagner, Christian Mougin, Titus Msagati, Joerg Oehlmann, Leo Posthuma, Malcolm Reid, Martin Reinhard, Susan D. Richardson, Et. Al.

Faculty Publications

The chemical pollution crisis severely threatens human and environmental health globally. To tackle this challenge the establishment of an overarching international science–policy body has recently been suggested. We strongly support this initiative based on the awareness that humanity has already likely left the safe operating space within planetary boundaries for novel entities including chemical pollution. Immediate action is essential and needs to be informed by sound scientific knowledge and data compiled and critically evaluated by an overarching science–policy interface body. Major challenges for such a body are (i) to foster global knowledge production on exposure, impacts and governance going beyond …


Structural And Computational Studies Of The Sars-Cov-2 Spike Protein Binding Mechanisms With Nanobodies: From Structure And Dynamics To Avidity-Driven Nanobody Engineering, Gennady M. Verkhivker Mar 2022

Structural And Computational Studies Of The Sars-Cov-2 Spike Protein Binding Mechanisms With Nanobodies: From Structure And Dynamics To Avidity-Driven Nanobody Engineering, Gennady M. Verkhivker

Mathematics, Physics, and Computer Science Faculty Articles and Research

Nanobodies provide important advantages over traditional antibodies, including their smaller size and robust biochemical properties such as high thermal stability, high solubility, and the ability to be bioengineered into novel multivalent, multi-specific, and high-affinity molecules, making them a class of emerging powerful therapies against SARS-CoV-2. Recent research efforts on the design, protein engineering, and structure-functional characterization of nanobodies and their binding with SARS-CoV-2 S proteins reflected a growing realization that nanobody combinations can exploit distinct binding epitopes and leverage the intrinsic plasticity of the conformational landscape for the SARS-CoV-2 S protein to produce efficient neutralizing and mutation resistant characteristics. Structural …


Location Of Cobalt Impurities In The Surface Oxide Of Stainless Steel 316l And Metal Release In Synthetic Biological Fluids, Xuying Wang, Jonas Hedberg, Heng-Yong Nie, Mark Biesinger, Inger Odnevall, Yolanda S. Hedberg Mar 2022

Location Of Cobalt Impurities In The Surface Oxide Of Stainless Steel 316l And Metal Release In Synthetic Biological Fluids, Xuying Wang, Jonas Hedberg, Heng-Yong Nie, Mark Biesinger, Inger Odnevall, Yolanda S. Hedberg

Chemistry Publications

Since 2021, cobalt (Co) is in Europe classified as carcinogen in quantities exceeding 0.1 wt-%. This affects nickel-rich stainless steels, which contain about 0.2 wt-% Co impurities. Previous findings show the bioaccessibility of Co in stainless steel to be primarily determined by the corrosion resistance. It has been unclear whether Co is distributed heterogeneously in the alloy and the outermost surface and whether a specific location would pose a risk for Co release under specific exposure conditions. This study aimed at locating Co in stainless steel 316L (0.2 wt-% Co) surfaces prior to and after exposure to different synthetic body …


Valence-, Dipole-And Quadropole-Bound Electronically Excited States Of Closed-Shell Anions Formed By Deprotonation Of Cyano-And Ethynyl-Disubstituted Polycyclic Aromatic Hydrocarbons, Marie E. Strauss, Taylor J. Santaloci, Ryan C. Fortenberry Mar 2022

Valence-, Dipole-And Quadropole-Bound Electronically Excited States Of Closed-Shell Anions Formed By Deprotonation Of Cyano-And Ethynyl-Disubstituted Polycyclic Aromatic Hydrocarbons, Marie E. Strauss, Taylor J. Santaloci, Ryan C. Fortenberry

Faculty and Student Publications

Dicyano-functionalized benzene and naphthalene anion derivatives exhibit a relatively rich population of electronically excited states in stark contrast to many assumptions regarding the photophysics of anions in general. The present work has quantum chemically analyzed the potential electronically excited states of closed-shell anions created by replacing hydrogen atoms with valence-bound lone pairs in benzene and naphthalene difunctionalized with combinations of-CN and-C2H. Dicyanobenzene anion derivatives can exhibit dipole-bound excited states as long as the cyano groups are not in para position to one another. This also extends to cyanoethynylbenzene anions as well as deprotonated dicyano-and cyanoethynylnaphthalene anion derivatives. Diethynyl functionalization is …


The Coastal Monitor: Vol. 8 No. 4, John Tanacredi Ph.D. Mar 2022

The Coastal Monitor: Vol. 8 No. 4, John Tanacredi Ph.D.

The Coastal Monitor

The original five acre of land portion of the historic Blue Points Oyster Company is located at the southern end of Atlantic Ave in West Sayville, Islip Town, Suffolk County, New York on the shore of Great South Bay. The Center for Environmental Research and Coastal Oceans Monitoring (CERCOM) is the science field station serving Molloy College’s BCES programs in Earth & Environmental Sciences and Biology. Our mission is to provide unique hands-on educational opportunities in the physical and life sciences, in collaboration with a host of Federal, State, and local and NGO groups, to bolster students’ career path. Great …


Chemical Thermodynamics—A Practical Wonderland, Rubin Battino, Trevor M. Letcher Mar 2022

Chemical Thermodynamics—A Practical Wonderland, Rubin Battino, Trevor M. Letcher

Chemistry Faculty Publications

Chemical thermodynamics is frequently thought of as being a hard subject and quite abstract. In fact, it is one of the most practical of subjects when you consider that the field of chemical engineering (responsible for endless useful applications) is effectively applied chemical thermodynamics. In this essay, examples of these applications are given, especially with respect to sustainability. The essay first considers the limits of thermodynamics and the constraints put on it in terms of the rigorous definitions of the principal function’s energy, entropy, and Gibbs energy.


Characterization Of Mechanochemical Modification Of Porous Silicon With Arginine, Jacklyn A. Dipietro, Kurt W. Kolasinski Mar 2022

Characterization Of Mechanochemical Modification Of Porous Silicon With Arginine, Jacklyn A. Dipietro, Kurt W. Kolasinski

Chemistry Faculty Publications

Mechanochemistry initiated the reaction of hydrogen-terminated porous silicon (H/por-Si) powder with arginine. Samples were analyzed using Fourier-transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), zeta potential, scanning electron microscopy (SEM), and photoluminescence (PL) spectroscopy. Arginine, which was physisorbed onto the surface of por-Si, blue-shifted the peak PL intensity from similar to 630 nm for the H/por-Si to similar to 565 nm for arginine-coated por-Si. Grinding for 4 h reduced >80% of the initially 2-45 mu m particles to <500 nm, but was observed to quench the PL. With appropriate rinsing and centrifugation, particles in the 100 nm range were isolated. Rinsing ground powder with water was required to remove the unreacted arginine. Without rinsing, excess arginine induced the aggregation of passivated particles. However, water reacted with the freshly ground por-Si powder producing H-2. A zeta potential of +42 mV was measured for arginine-terminated por-Si particles dispersed in deionized water. This positive value was consistent with termination such that NH2 groups extended away from the surface. Furthermore, this result was confirmed by FTIR spectra, which suggested that arginine was bound to silicon through the formation of a covalent Si-O bond.


Natural Phaeosphaeride A Derivatives Overcome Drug Resistance Of Tumor Cells And Modulate Signaling Pathways, Victoria Abzianidze, Natalia Moiseeva, Diana Suponina, Sofya Zakharenkova, Nadezhda Rogovskaya, Lidia Laletina, Alvin A. Holder, Denis Krivorotov, Alexander Bogachenkov, Alexander Garabadzhiu, Anton Ukolov, Vyacheslav Kosorukov Mar 2022

Natural Phaeosphaeride A Derivatives Overcome Drug Resistance Of Tumor Cells And Modulate Signaling Pathways, Victoria Abzianidze, Natalia Moiseeva, Diana Suponina, Sofya Zakharenkova, Nadezhda Rogovskaya, Lidia Laletina, Alvin A. Holder, Denis Krivorotov, Alexander Bogachenkov, Alexander Garabadzhiu, Anton Ukolov, Vyacheslav Kosorukov

Chemistry & Biochemistry Faculty Publications

n the present study, natural phaeosphaeride A (PPA) derivatives are synthesized. Anti-tumor studies are carried out on the PC3, K562, HCT-116, THP-1, MCF-7, A549, NCI-H929, Jurkat, and RPMI8226 tumor cell lines, and on the human embryonic kidney (HEK293) cell line. All the compounds synthesized turned out to have better efficacy than PPA towards the tumor cell lines listed. Among them, three compounds exhibited an ability to overcome the drug resistance of tumor cells associated with the overexpression of the P-glycoprotein by modulating the work of this transporter. Luminex xMAP technology was used to assess the effect of five synthesized compounds …


4,6-O-Phenylethylidene Acetal Protected D-Glucosamine Carbamate-Based Gelators And Their Applications For Multi-Component Gels, Pooja Sharma, Guijun Wang Mar 2022

4,6-O-Phenylethylidene Acetal Protected D-Glucosamine Carbamate-Based Gelators And Their Applications For Multi-Component Gels, Pooja Sharma, Guijun Wang

Chemistry & Biochemistry Faculty Publications

The self-assembly of carbohydrate-based low molecular weight gelators has led to useful advanced soft materials. The interactions of the gelators with various cations and anions are important in creating novel molecular architectures and expanding the scope of the small molecular gelators. In this study, a series of thirteen new C-2 carbamates of the 4,6-O-phenylethylidene acetalprotected D-glucosamine derivatives has been synthesized and characterized. These compounds are rationally designed from a common sugar template. All carbamates synthesized were found to be efficient gelators and three compounds are also hydrogelators. The resulting gels were characterized using optical microscopy, atomic force microscopy, …


Transition Metal‐Catalyzed And Mao‐Assisted Olefin Polymerization. Cyclic Isomers Of Sinn’S Dimer Are Excellent Ligands In Iron Complexes And Great Methylating Reagents, Kaidi Yang, Rainer Glaser Mar 2022

Transition Metal‐Catalyzed And Mao‐Assisted Olefin Polymerization. Cyclic Isomers Of Sinn’S Dimer Are Excellent Ligands In Iron Complexes And Great Methylating Reagents, Kaidi Yang, Rainer Glaser

Chemistry Faculty Research & Creative Works

Methylaluminoxane (MAO) is the most commonly used co‐catalyst for transition metalcatalyzed olefin polymerization, but the structures of MAO species and their catalytic functions remain topics of intensive study. We are interested in MAO‐assisted polymerization with catalysts L(R2)FeCl2 (L = tridentate pyridine‐2,6‐diyldimethanimine; imine‐R = Me, Ph). It is our hypothesis that the MAO species is not merely enabling Fe−Me bond formation but functions as an integral part of the active catalyst, a MAO adduct of the Fe‐precatalyst [L(R2)FeCl]+. In this paper, we explored the possible structures of acyclic and cyclic MAO species and their …


Thiol Antioxidants Protect Human Lens Epithelial (Hle B-3) Cells Against Tert-Butyl Hydroperoxide-Induced Oxidative Damage And Cytotoxicity, Annalise Pfaff, Anna Chernatynskaya, Hannah Vineyard, Nuran Ercal Mar 2022

Thiol Antioxidants Protect Human Lens Epithelial (Hle B-3) Cells Against Tert-Butyl Hydroperoxide-Induced Oxidative Damage And Cytotoxicity, Annalise Pfaff, Anna Chernatynskaya, Hannah Vineyard, Nuran Ercal

Chemistry Faculty Research & Creative Works

Oxidative damage to lens epithelial cells plays an important role in the development of age-related cataract, and the health of the lens has important implications for overall ocular health. As a result, there is a need for effective therapeutic agents that prevent oxidative damage to the lens. Thiol antioxidants such as tiopronin or N-(2-mercaptopropionyl)glycine (MPG), N-acetylcysteine amide (NACA), N-acetylcysteine (NAC), and exogenous glutathione (GSH) may be promising candidates for this purpose, but their ability to protect lens epithelial cells is not well understood. The effectiveness of these compounds was compared by exposing human lens epithelial cells (HLE B-3) to the …


Studying Acetylation Of Aconitase Isozymes By Genetic Code Expansion, Jessica Araujo, Sara Ottinger, Sumana Venkat, Qinglei Gan, Chenguang Fan Mar 2022

Studying Acetylation Of Aconitase Isozymes By Genetic Code Expansion, Jessica Araujo, Sara Ottinger, Sumana Venkat, Qinglei Gan, Chenguang Fan

Chemistry & Biochemistry Faculty Publications and Presentations

Aconitase catalyzes the second reaction of the tricarboxylic acid cycle, the reversible conversion of citrate and isocitrate. Escherichia coli has two isoforms of aconitase, AcnA and AcnB. Acetylomic studies have identified acetylation at multiple lysine sites of both E. coli aconitase isozymes, but the impacts of acetylation on aconitases are unknown. In this study, we applied the genetic code expansion approach to produce 14 site-specifically acetylated aconitase variants. Enzyme assays and kinetic analyses showed that acetylation of AcnA K684 decreased the enzyme activity, while acetylation of AcnB K567 increased the enzyme activity. Further in vitro acetylation and deacetylation assays were …


Computational Characterization Of Charge Transport Resiliency In Molecular Solids, Balaji Sesha Sarath Pokuri, Seab M. Ryno, Ramin Noruzi, Chad Risko, Baskar Ganapathysubramanian Mar 2022

Computational Characterization Of Charge Transport Resiliency In Molecular Solids, Balaji Sesha Sarath Pokuri, Seab M. Ryno, Ramin Noruzi, Chad Risko, Baskar Ganapathysubramanian

Chemistry Faculty Publications

Organic semiconductors have found utility in a diverse array of applications. A key property impacting device performance is the charge transport mobility of the molecular solids making up the active layer in these devices. There is increasing interest in accessing, quantifying, and understanding the resilience of charge transport mobility to thermal, mechanical, and chemical perturbations in molecular solids. Here, we integrate molecular simulations with graph characterization to quantify the resilience of charge transport. We consider all-atom simulations of the PTB7 system and build on earlier graph approaches to rapidly characterize the charge mobility of the PTB7 molecular simulations. We introduce …


Continuum Dynamics And Statistical Correction Of Compositional Heterogeneity In Multivalent Idp Oligomers Resolved By Single-Particle Em, Barmak Mostofian, Russell Mcfarland, Aiden Estelle, Jesse Howe, Elisar J. Barbar, Steve L. Reichow, Daniel M. Zuckerman Mar 2022

Continuum Dynamics And Statistical Correction Of Compositional Heterogeneity In Multivalent Idp Oligomers Resolved By Single-Particle Em, Barmak Mostofian, Russell Mcfarland, Aiden Estelle, Jesse Howe, Elisar J. Barbar, Steve L. Reichow, Daniel M. Zuckerman

Chemistry Faculty Publications and Presentations

Multivalent intrinsically disordered protein (IDP) complexes are prevalent in biology and act in regulation of diverse processes, including transcription, signaling events, and the assembly and disassembly of complex macromolecular architectures. These systems pose significant challenges to structural investigation, due to continuum dynamics imparted by the IDP and compositional heterogeneity resulting from characteristic low-affinity interactions. Here, we developed a modular pipeline for automated single-particle electron microscopy (EM) distribution analysis of common but relatively understudied semi-ordered systems: 'beads-on-a-string' assemblies, composed of IDPs bound at multivalent sites to the ubiquitous ∼20kDacross-linking hub protein LC8. This approach quantifies conformational geometries and compositional heterogeneity on …


Students’ Engagement In Education As Sustainability: Implementing An Ethical Dilemma-Steam Teaching Model In Chemistry Learning, Yuli Rahmawati, Elisabeth Taylor, Peter Charles Taylor, Achmad Ridwan, Alin Mardiah Mar 2022

Students’ Engagement In Education As Sustainability: Implementing An Ethical Dilemma-Steam Teaching Model In Chemistry Learning, Yuli Rahmawati, Elisabeth Taylor, Peter Charles Taylor, Achmad Ridwan, Alin Mardiah

Research outputs 2022 to 2026

This paper reports the results of a study on the implementation of the Ethical Dilemma STEAM Teaching Model in secondary schools in Jakarta, Indonesia. This interdisciplinary curriculum approach employed ‘ethical dilemma story pedagogy’ in a STEAM education project designed to engage students in values-based chemistry learning. Drawing on the arts, specially written ethical dilemma stories posing real-world environmental problems engaged students in exploring their value systems. Students reflected on the pros and cons of ethical dilemmas related to the everyday use of artificial fertilizers, disposal of used cooking oil and detergent waste, and environmental pollution caused by plastic waste. The …


Facet Dependent Oxygen Evolution Activity Of Spinel Cobalt Oxides, Li-Hua Zhang, Hong-Yuan Chuai, Hai Liu, Qun Fan, Si-Yu Kuang, Sheng Zhang, Xin-Bin Ma Feb 2022

Facet Dependent Oxygen Evolution Activity Of Spinel Cobalt Oxides, Li-Hua Zhang, Hong-Yuan Chuai, Hai Liu, Qun Fan, Si-Yu Kuang, Sheng Zhang, Xin-Bin Ma

Journal of Electrochemistry

Water splitting is a promising technology to produce clean hydrogen if powered by renewable energies, where oxygen evolution is the rate determining step at an anode. Here we adjust the different crystal planes of the cobalt oxides catalyst to expose more effective active sites through a hydrothermal process, so as to improve the reaction activity for oxygen evolution. The samples were well characterized by TEM, SEM and XRD. Among the three synthetic crystal planes (100), (111) and (110) of spinel cobalt oxides, the (100) crystal plane has the highest intrinsic activity. Combining in-situ infrared and DFT calculations, we …


Structural Degradation Of Ni-Rich Layered Oxide Cathode For Li-Ion Batteries, Jia-Yi Wang, Sheng-Nan Guo, Xin Wang, Lin Gu, Dong Su Feb 2022

Structural Degradation Of Ni-Rich Layered Oxide Cathode For Li-Ion Batteries, Jia-Yi Wang, Sheng-Nan Guo, Xin Wang, Lin Gu, Dong Su

Journal of Electrochemistry

Nickel(Ni)-rich layered oxide has been regarded as one of the most important cathode materials for the lithium-ion batteries because of its low cost and high energy density. However, the concerns in safety and durability of this compound are still challenging for its further development. On this account, the in-depth understanding in the structural factors determining its capacity attenuation is essential. In this review, we summarize the recent advances on the degradation mechanisms of Ni-rich layered oxide cathode. Progresses in the structure evolution of Ni-rich oxide are carefully combed in terms of inner evolution, surface evolution, and the property under thermal …


A Beginners’ Guide To Modelling Of Electric Double Layer Under Equilibrium, Nonequilibrium And Ac Conditions, Lu-Lu Zhang, Chen-Kun Li, Jun Huang Feb 2022

A Beginners’ Guide To Modelling Of Electric Double Layer Under Equilibrium, Nonequilibrium And Ac Conditions, Lu-Lu Zhang, Chen-Kun Li, Jun Huang

Journal of Electrochemistry

In electrochemistry, perhaps also in other time-honored scientific disciplines, knowledge labelled classical usually attracts less attention from beginners, especially those pressured or tempted to quickly jam into research fronts that are labelled, not always aptly, modern. In fact, it is a normal reaction to the burden of history and the stress of today. Against this context, accessible tutorials on classical knowledge are useful, should some realize that taking a step back could be the best way forward. This is the driving force of this article themed at physicochemical modelling of the electric (electrochemical) double layer (EDL). We begin the exposition …


Magnetic Resonance In Metal-Ion Batteries: From Nmr (Nuclear Magnetic Resonance) To Epr (Electron Paramagnetic Resonance), Bing-Wen Hu, Chao Li, Fu-Shan Geng, Ming Shen Feb 2022

Magnetic Resonance In Metal-Ion Batteries: From Nmr (Nuclear Magnetic Resonance) To Epr (Electron Paramagnetic Resonance), Bing-Wen Hu, Chao Li, Fu-Shan Geng, Ming Shen

Journal of Electrochemistry

Metal-ion batteries have changed our quotidian lives. The research on the electrode materials for metal-ion battery is the key to improve the performance of the battery. Therefore, understanding the structure-performance relationship of the electrode materials can help to improve the energy density and power density of the materials. Magnetic resonance, including nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR), has been continuously improved during the past three decades, and has gradually become one of the important technologies to study the structure-performance relationship of electrode materials. This paper summarizes the progress of magnetic resonance research from our group on several …


Recent Advances In Electrochemical Kinetics Simulations And Their Applications In Pt-Based Fuel Cells, Ji-Li Li, Ye-Fei Li, Zhi-Pan Liu Feb 2022

Recent Advances In Electrochemical Kinetics Simulations And Their Applications In Pt-Based Fuel Cells, Ji-Li Li, Ye-Fei Li, Zhi-Pan Liu

Journal of Electrochemistry

Theoretical simulations of electrocatalysis are vital for understanding the mechanism of the electrochemical process at the atomic level. It can help to reveal the in-situ structures of electrode surfaces and establish the microscopic mechanism of electrocatalysis, thereby solving the problems such as electrode oxidation and corrosion. However, there are still many problems in the theoretical electrochemical simulations, including the solvation effects, the electric double layer, and the structural transformation of electrodes. Here we review recent advances of theoretical methods in electrochemical modeling, in particular, the double reference approach, the periodic continuum solvation model based on the modified Poisson-Boltzmann …


Recent Advances In Structural Regulation On Non-Precious Metal Catalysts For Oxygen Reduction Reaction In Alkaline Electrolytes, Xue Wang, Li Zhang, Chang-Peng Liu, Jun-Jie Ge, Jian-Bing Zhu, Wei Xing Feb 2022

Recent Advances In Structural Regulation On Non-Precious Metal Catalysts For Oxygen Reduction Reaction In Alkaline Electrolytes, Xue Wang, Li Zhang, Chang-Peng Liu, Jun-Jie Ge, Jian-Bing Zhu, Wei Xing

Journal of Electrochemistry

Oxygen reduction reaction (ORR) in alkaline electrolytes is an important electrochemical process for metal-air batteries and anion exchange membrane fuel cells (AEMFCs). However, the sluggish kinetics spurs intensive research on searching robust electrocatalysts. Non-precious metal catalysts (NPMCs) that can circumvent the cost and scarcity issues associated with platinum (Pt)-based materials have been pursued and the challenges lie in the performance improvement to rival Pt-based benchmarks. As the composition and structure of the NPMCs have a significant impact on the catalytic performance, precise regulation on the catalyst structure holds great promise to bridge the activity gap between NPMCs and Pt-based benchmarks. …


Selective Co2 Reduction To Formate On Heterostructured Sn/Sno2 Nanoparticles Promoted By Carbon Layer Networks, Xue Teng, Yanli Niu, Shuaiqi Gong, Xuan Liu, Zuofeng Chen Feb 2022

Selective Co2 Reduction To Formate On Heterostructured Sn/Sno2 Nanoparticles Promoted By Carbon Layer Networks, Xue Teng, Yanli Niu, Shuaiqi Gong, Xuan Liu, Zuofeng Chen

Journal of Electrochemistry

Tin (Sn)-based materials have emerged as promising electrocatalysts for selective reduction of CO2 to formate, but their overall performances are still limited by electrode structures which govern the accessibility to active sites, the electron transfer kinetics, and the catalytic stability. In this study, the heterostructured Sn/SnO2 nanoparticles dispersed by N-doped carbon layer networks (Sn/SnO2@NC) were synthesized by a melt-recrystallization method taking the low melting point of Sn (m.p. 232oC). The N-doped carbon layer networks derived from polydopamine could attract more electrons on the electrocatalyst, serve as conductive agents and protect the ultrafine nanoparticles from …