Open Access. Powered by Scholars. Published by Universities.®

Analytical Chemistry Commons™

Open Access. Powered by Scholars. Published by Universities.®

2020

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 91 - 120 of 141

Full-Text Articles in Analytical Chemistry

Characterization Of Coal Particles In The Soil Of A Former Rail Yard And Urban Brownfield: Liberty State Park, Jersey City (Nj), Usa, Diane F. Hagmann, Michael A. Kruge, Nina M. Goodey, Jennifer Adams Krumins Jan 2020

Characterization Of Coal Particles In The Soil Of A Former Rail Yard And Urban Brownfield: Liberty State Park, Jersey City (Nj), Usa, Diane F. Hagmann, Michael A. Kruge, Nina M. Goodey, Jennifer Adams Krumins

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

From the 1850's until the 1960's, the Central Railroad of New Jersey was among several major railways shipping anthracite and bituminous coal to the New York City area, transferring coal from railcar to barge at its extensive rail yard and port facility in Jersey City. The 490 ha Liberty State Park was developed on the site after the rail yard closed, but a ca. 100 ha brownfield zone within the park remains off limits to visitors pending future remediation. As part of an environmental forensic and industrial archeological investigation of this zone, the present study characterizes anthracite and bituminous coal …

Go to article

Development Of Novel Analytical Methods For Detection And Determination Of Tamoxifen In Oral Fluid And Discrimination Between Regioisomeric Aromatase Inhibitors For Doping Control Purposes, Brooke A. Sutton Jan 2020

Development Of Novel Analytical Methods For Detection And Determination Of Tamoxifen In Oral Fluid And Discrimination Between Regioisomeric Aromatase Inhibitors For Doping Control Purposes, Brooke A. Sutton

Online Theses and Dissertations

The use of SERMs (Selective Estrogen Receptor Modulators) – most notably the drug Tamoxifen – has significantly increased among athletes over the past decade to enhance athletic performance and/or negate certain side effects of using anabolic steroids. This “doping” is always banned by WADA (World Anti-Doping Agency) for all athletes, but SERMs can naturally increase testosterone production so they are a tempting alternative to using steroids or androgenic supplements that can cause significant health problems (e.g. acne, breast development, frequent urge to urinate, low libido, etc.). Similarly, the use of AIs (Aromatase Inhibitors) has also increased among athletes for identical …

Go to article

Effects Of Nutrient Overload And Environmental Conditions On Algal Bloom Formation: A Case Study Of Water Sources In Eastern Kentucky, Lauren Sutton Jan 2020

Effects Of Nutrient Overload And Environmental Conditions On Algal Bloom Formation: A Case Study Of Water Sources In Eastern Kentucky, Lauren Sutton

Online Theses and Dissertations

Eastern Kentucky is home to many private ponds used for agricultural and recreational purposes. Each year, the owners of these ponds observe harmful algal blooms (HABs) that release toxins into the water, potentially limiting the use of these ponds. A pilot study in summer 2018 observed a harmful algal bloom (HAB) occurring in one pond in Madison Country that roughly correlated with a rise in water sulfate levels with no detectable levels of nitrate or phosphate present. A follow-up study of this pond and others in the area was conducted during Summer 2019. The purpose of this project was three-fold: …

Go to article

Detection Of Biomolecules Via Ocp Measurements Using Npg Electrodes, Borkat Ullah Jan 2020

Detection Of Biomolecules Via Ocp Measurements Using Npg Electrodes, Borkat Ullah

Theses and Dissertations

In sensing application nanoporous gold (NPG) has attracted much attention. NPG is prepared by dealloying Au:Ag alloys. Characterization was done using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and cyclic voltammetry (CV). In this work, the open circuit potential (OCP) of ferricyanide, cysteine, uric acid, and ascorbic acid was measured in phosphate buffer solution (PBS) and biofouling solution containing bovine serum albumin (BSA) at pH 7.4. OCP measurement has been hindered due to biofouling and surface passivation on the metal electrodes. By the use of the NPG electrodes, electrochemical activity can be maintained. From the OCP measurement of cysteine, …

Go to article

Solid Phase Extraction And High-Precision Mass Spectrometry Analysis Methods For Crassostrea Virginica Metabolome, Alyssa Darling Jan 2020

Solid Phase Extraction And High-Precision Mass Spectrometry Analysis Methods For Crassostrea Virginica Metabolome, Alyssa Darling

Theses and Dissertations

Metabolomics is the rapidly-growing field which focuses on the endpoints of biological processes, and has the capability to provide a snapshot of an organisms’ interaction with their environment on a molecular scale. The objective of the experiment herein was to develop a standard metabolic extraction technique coupled with ultrahigh-precision analytical tools to build a global metabolic pathway of the keystone species Crassostrea virginica. To achieve this, C. virginica whole-body samples were extracted using acetonitrile and methanol, then split into a dehydrated group and a diluted group. Following reversed-phase solid phase extraction (RP-SPE) of both groups, metabolites were identified using …

Go to article

Understanding The Rage Signaling Pathway And Its Contribution To Diabetic Complications, Leon Vegas Ho Jan 2020

Understanding The Rage Signaling Pathway And Its Contribution To Diabetic Complications, Leon Vegas Ho

Legacy Theses & Dissertations (2009 - 2024)

The binding of advanced glycation end products (AGEs) to the receptor for advanced glycation end products (RAGE) is an important feature of the RAGE signaling pathway that plays a role in the pathogenesis of diabetes. Under high glucose concentration, RAGE expression increases immensely from the formation of a Schiff base by glucose bounded to lysine. This triggers an inflammatory and immune response and upregulates the expression of RAGE and causes an accumulation of AGEs in the body. As a result, this leads to the development of diabetes and other complications such as, atherosclerosis, nephrothapy, and retinopathy. To remedy AGE accumulation, …

Go to article

Towards Machine Learning In Chemical Sensing : Milk Differentiation And Quality Control Through Two-Dimensional Nano-Sensor Array, Yu Sheng Chen Jan 2020

Towards Machine Learning In Chemical Sensing : Milk Differentiation And Quality Control Through Two-Dimensional Nano-Sensor Array, Yu Sheng Chen

Legacy Theses & Dissertations (2009 - 2024)

Herein, we developed a novel artificial tongue using machine learning and 12 nanoassemblies (2D-NAs) to identify and analyzed different kinds of milk beverages for quality control. This biomimetic sensor array was trained to “taste” different milk types as an “artificial tongue” which is the first time we demonstrated that this sensor array can be implemented to complex systems. Two-dimensional nanoparticles (2D-nps) and nine fluorescently labeled single stranded oligonucleotides (ssDNA) with different length and nucleobases were assembled to create 12 2D-NAs. The artificial tongue was deployed to identify and analyze five milk types. All five milk types were discriminated with 95% …

Go to article

Elemental Composition And Arsenic Speciation Analysis Of Processed Seafood Products Using Atomic Spectrometric Techniques, Austin A. Roberts Jan 2020

Elemental Composition And Arsenic Speciation Analysis Of Processed Seafood Products Using Atomic Spectrometric Techniques, Austin A. Roberts

Legacy Theses & Dissertations (2009 - 2024)

Arsenic (As) is a widely known toxic element that is highly ubiquitous and has been detected in soil, sediment, naturals waters, the atmosphere, and in organisms of the 5 kingdoms. The toxicity of As however, is dependent on the molecular form in which it takes as well as the route of exposure. For the general population, exposure to As mainly takes place via ingestion of food and water, which have led to numerous studies investigating As and it’s various species in these matrices. Seafood is one of the major sources of dietary exposure to As and has thus led to …

Go to article

Biochemical And Chemical Methods Of Key Derivation For Cryptographic Ciphers, Leif K. Mcgoldrick Jan 2020

Biochemical And Chemical Methods Of Key Derivation For Cryptographic Ciphers, Leif K. Mcgoldrick

Legacy Theses & Dissertations (2009 - 2024)

Cryptography is a vital component of digital communication and digital data in general. The use of cryptography is necessary to support the veracity of data and to protect it from outside parties with malicious intent. Cryptography focuses on two main facets that are vital for this goal: data encryption and user authentication. Encryption protects the data by transforming it into an encrypted text that would not allow someone access without having or breaking the encryption method that was used to make it. User authentication is a multiple part process that allows for one to be able to identify oneself to …

Go to article

Utilizing Raman Spectroscopy And Chemometrics For Novel Medical Diagnostic Purposes, Nicole M. Ralbovsky Jan 2020

Utilizing Raman Spectroscopy And Chemometrics For Novel Medical Diagnostic Purposes, Nicole M. Ralbovsky

Legacy Theses & Dissertations (2009 - 2024)

Many problems exist within the myriad of currently employed diagnostic techniques. Further, an incredibly wide variety of procedures are used to identify an even greater number of diseases which exist in the world. There is a definite unmet clinical need to improve the diagnostic capabilities of these methods, including improving test sensitivity and specificity, objectivity and definitiveness, and reducing cost and how invasive a test is, with an interest in replacing multiple diagnostic methods with one powerful tool. That is, the development of a singular technique which can accurately and objectively diagnose a wide variety of diseases in a cost-effective …

Go to article

Investigation Of Underpotential Deposition Of Copper At Heated Gold Loop Screen-Printed Electrodes In A Variety Of Water Samples, Eun-Ju Lee Jan 2020

Investigation Of Underpotential Deposition Of Copper At Heated Gold Loop Screen-Printed Electrodes In A Variety Of Water Samples, Eun-Ju Lee

Legacy Theses & Dissertations (2009 - 2024)

To study the underpotential deposition (UPD) of copper, three different types of water samples (TraceSelect® Ultra-pure water, Indian pond water at University at Albany and tap water) are used at a heated gold loop screen-printed electrode (GLE), which is a new type of heated working electrode for voltammetry measurements that is able to directly detect the copper content in the water samples. The anodic stripping analysis of copper is performed with these gold loop electrodes at room temperature of 25 °C and electrode temperature of 80 °C at two different deposition potentials, -0.20 V and +0.10 V. Furthermore, the concentration …

Go to article

Bioaffinity-Based Methods For Forensic, Biometric, And Clinical Purposes, Mindy Elizabeth Hair Jan 2020

Bioaffinity-Based Methods For Forensic, Biometric, And Clinical Purposes, Mindy Elizabeth Hair

Legacy Theses & Dissertations (2009 - 2024)

Biomarker analysis is a well-established discipline that involves the evaluation of biological samples for the presence of various substances indicative of personal attributes or illnesses. Sweat is one example of a biological fluid that is often overlooked for forensic and clinical analyses, even though it can contain DNA, various amino acids, and other low molecular weight compounds.1–3 The work presented in this dissertation focuses on the use of bioaffinity-based assays to quantify biomarkers in sweat for both forensic and clinical applications. The concentration of the biochemical content within an individual’s sweat are controlled by hormone-based metabolic pathways4 that fluctuate daily …

Go to article

Metabolic Changes Associated With Adaptive Resistance To Daptomycin In Streptococcus Mitis-Oralis, Allison Parrett, Joseph M. Reed, Stewart G. Gardner, Nagendra N. Mishra, Arnold S. Bayer, Robert Powers, Greg A. Somerville Jan 2020

Metabolic Changes Associated With Adaptive Resistance To Daptomycin In Streptococcus Mitis-Oralis, Allison Parrett, Joseph M. Reed, Stewart G. Gardner, Nagendra N. Mishra, Arnold S. Bayer, Robert Powers, Greg A. Somerville

Department of Chemistry: Faculty Publications

Background: Viridans group streptococci of the Streptococcus mitis-oralis subgroup are important endovascular pathogens. They can rapidly develop high-level and durable non-susceptibility to daptomycin both in vitro and in vivo upon exposure to daptomycin. Two consistent genetic adaptations associated with this phenotype (i.e., mutations in cdsA and pgsA) lead to the depletion of the phospholipids, phosphatidylglycerol and cardiolipin, from the bacterial membrane. Such alterations in phospholipid biosynthesis will modify carbon flow and change the bacterial metabolic status. To determine the metabolic differences between daptomycin-susceptible and non- susceptible bacteria, the physiology and metabolomes of S. mitis-oralis strains 351 (daptomycin-susceptible) and 351-D10 (daptomycin …

Go to article

Development Of Analytical Methods For Toxic Inhaled Hazards (Tih) And Their Metabolites, Obed Adu Gyamfi Jan 2020

Development Of Analytical Methods For Toxic Inhaled Hazards (Tih) And Their Metabolites, Obed Adu Gyamfi

Electronic Theses and Dissertations

Toxic inhalation hazards (TIHs), such as methyl isocyanate (MIC) and hydrogen cyanide (HCN), are noxious gases and vapors that are harmful, and often deadly, to humans. However, because of their low cost and high reactivity, they are extensively used for industrial productions, creating risk of exposure for both industrial workers (e.g., occupational exposure) and civilians (e.g., accidental release during transport). The illicit use of TIHs, including as terrorist agents, is also concerning. Considering the rapid toxicity of TIHs and the danger they pose to both human and animal lives, there is a critical need to develop of analytical methods for …

Go to article

Design, Construction, And Characterization Of A Combined Mini-Co₂/Voc Sensor And Gas Chromatograph For Field Research, Rishi Basdeo, Michael Hampton Jan 2020

Design, Construction, And Characterization Of A Combined Mini-Co₂/Voc Sensor And Gas Chromatograph For Field Research, Rishi Basdeo, Michael Hampton

Digital Repository: Showcase of Undergraduate Research Excellence

No abstract provided.

Go to article

An Ammonia Sensor Using An Unadorned Bromocresol Layer, John Cassidy, Caoimhe Ní Néill, Merve Akdağ, Tony Betts Jan 2020

An Ammonia Sensor Using An Unadorned Bromocresol Layer, John Cassidy, Caoimhe Ní Néill, Merve Akdağ, Tony Betts

Articles

Bromocresol Purple,(BCP) cast onto an acetate sheet, was used to sense ammonia. This simple layer responded reversibly to a low concentration ( 15 ppm) of ammonia in the presence of water vapour. The BCP solution was spincoated on an acetate sheet from a solution in dichloromethane. This layer was exposed to nitrogen and NH3/H2O vapour in quick succession. The colour change occurred from yellow to purple rapidly in the solid state. The λmax for the neutral ( acid) form of the BCP was found to be 435 nm and the λmax for the dianion ( base form) of the BCP …

Go to article

Gc-Ms Analysis Of Synthesized Biodiesel, Courtney R. Whetstine Jan 2020

Gc-Ms Analysis Of Synthesized Biodiesel, Courtney R. Whetstine

Forensic Science Master's Projects

Biodiesel is an alternative energy resource that can replenish depleting natural petroleum storage. Synthesis of biodiesel is cost-efficient as it can be chemically converted from renewable wastes, such as vegetable oil or animal fat. These fuels are also biodegradable and the exhaust emissions from biodiesel are non-toxic and environmentally-friendly. Biodiesel is a stable fuel that performs reliably in all diesel engines. Biodiesel is also easy to synthesize, safe to handle, and works with diesel fuel storage and pumping systems. The United States has an abundance of vegetable oils that have not been widely used to our advantage. Additionally, fast-food restaurants …

Go to article

A Validated Uplc-Ms/Ms Method For The Determination Of Aliphatic And Aromatic Isocyanate Exposure In Human Urine, Maggy Lépine, Lekha Sleno, Jacques Lesage, Sébastien Gagné Jan 2020

A Validated Uplc-Ms/Ms Method For The Determination Of Aliphatic And Aromatic Isocyanate Exposure In Human Urine, Maggy Lépine, Lekha Sleno, Jacques Lesage, Sébastien Gagné

Études primaires

4,4′-Methylenediphenyldiisocyanate (MDI), toluenediisocyanate (2,4-TDI and 2,6-TDI), and 1,6′-hexamethylenediisocyanate (HDI) are all commonly used in the production of polyurethane-containing materials in different application areas. Workers exposed occupationally to these compounds may develop sensitization with the potential to lead to asthma. Isocyanates are metabolized in vivo by conjugation to macromolecules and/or by acetylation prior to being eliminated in urine. The hydrolysis of urine samples releases free amine compounds from these metabolites as biomarkers of exposure, specific to each parent isocyanate: 4,4′-methylenedianiline (MDA), toluenediamine (2,4-TDA and 2,6-TDA), and hexamethylenediamine (HDA). To address the need for a validated method that could be used for …

Go to article

Method Development For The Analysis Of Fatty Acids In Adipose Tissue Using Stir Bar Sorptive Extraction Coupled With Gas Chromatography-Mass Spectrometry, Angela Marisol Encerrado Manriquez Jan 2020

Method Development For The Analysis Of Fatty Acids In Adipose Tissue Using Stir Bar Sorptive Extraction Coupled With Gas Chromatography-Mass Spectrometry, Angela Marisol Encerrado Manriquez

Open Access Theses & Dissertations

The project was aimed to develop an easy and sensitive analytical tool to study the role of fatty acids (FAs) profile in periprostatic adipose tissue (PPAT) and prostate cancer (PCa). PCa is the second leading cause of cancer-related death among American men. Although obesity has been mostly ruled out by many researchers as a risk factor for developing PCa, it has shown to be associated with PCa metastasis and progression. Periprostatic adipose tissue, which was present on 48% of prostatic surfaces, has been reported to act as energy sources for facilitating a positive microenvironment for PCa tumor progression. To understand …

Go to article

Development Of A Method For The Detection And Quantification Of Various Benzodiazepines And Z-Drugs In Human Blood And Qualitative Identification In Urine Samples Using Liquid Chromatography Mass Spectrometry (Lc-Ms/Ms), Haley Michel Jan 2020

Development Of A Method For The Detection And Quantification Of Various Benzodiazepines And Z-Drugs In Human Blood And Qualitative Identification In Urine Samples Using Liquid Chromatography Mass Spectrometry (Lc-Ms/Ms), Haley Michel

Williams Honors College, Honors Research Projects

This method developed in the toxicology department at the Cuyahoga County Medical Examiner’s Office (CCMEO) detects 40 benzodiazepines and metabolites along with several z-drugs in blood and urine by liquid chromatography tandem mass spectrometry. A sample amount of 0.5 mL was used to detect analytes in postmortem drug facilitated sexual assault and impaired driving cases. Twenty-nine analytes met criteria for quantification while the remaining 14 were used as qualitative indicators. Bias and precision results for quality controls met criteria, staying within ±15% except for clonazolam and etizolam which were within ±20%. Quantitative reporting criteria which included dilution integrity was met …

Go to article

Resolving The Puzzle Of Single-Atom Silver Dispersion On Nanosized Γ-Al2O3 Surface For High Catalytic Performance, Fei Wang, Jinzhu Ma, Shaohui Xin, Qiang Wang, Jun Xu, Changbin Zhang, Hong He, Xiao Cheng Zeng Jan 2020

Resolving The Puzzle Of Single-Atom Silver Dispersion On Nanosized Γ-Al2O3 Surface For High Catalytic Performance, Fei Wang, Jinzhu Ma, Shaohui Xin, Qiang Wang, Jun Xu, Changbin Zhang, Hong He, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

Ag/γ-Al2O3 is widely used for catalyzing various reactions, and its performance depends on the valence state, morphology and dispersion of Ag species. However, detailed anchoring mechanism of Ag species on γ-Al2O3 remains largely unknown. Herein, we reveal that the terminal hydroxyls on γ-Al2O3 are responsible for anchoring Ag species. The abundant terminal hydroxyls existed on nanosized γ-Al2O3 can lead to single-atom silver dispersion, thereby resulting in markedly enhanced performance than the Ag cluster on microsized γ-Al2O3. Density-functional-theory calculations confirm that Ag atom is mainly …

Go to article

Carbon Oxidation State In Microbial Polar Lipids Suggests Adaptation To Hot Spring Temperature And Redox Gradients, Grayson M. Boyer, Florence Schubotz, Roger E. Summons, Jade Woods, Everett L. Shock Jan 2020

Carbon Oxidation State In Microbial Polar Lipids Suggests Adaptation To Hot Spring Temperature And Redox Gradients, Grayson M. Boyer, Florence Schubotz, Roger E. Summons, Jade Woods, Everett L. Shock

Department of Chemistry: Faculty Publications

The influence of oxidation-reduction (redox) potential on the expression of biomolecules is a topic of ongoing exploration in geobiology. In this study, we investigate the novel possibility that structures and compositions of lipids produced by microbial communities are sensitive to environmental redox conditions. We extracted lipids from microbial biomass collected along the thermal and redox gradients of four alkaline hot springs in Yellowstone National Park (YNP) and investigated patterns in the average oxidation state of carbon (ZC), a metric calculated from the chemical formulae of lipid structures. Carbon in intact polar lipids (IPLs) and their alkyl chains becomes …

Go to article

Surface Modification Of Silicon Nanowire Based Field Effect Transistors With Stimuli Responsive Polymer Brushes For Biosensing Applications, Stephanie Klinghammer, Sebastian Rauch, Sebastian Pregl, Petra Uhlmann, Larysa Baraban, Gianaurelio Cuniberti Jan 2020

Surface Modification Of Silicon Nanowire Based Field Effect Transistors With Stimuli Responsive Polymer Brushes For Biosensing Applications, Stephanie Klinghammer, Sebastian Rauch, Sebastian Pregl, Petra Uhlmann, Larysa Baraban, Gianaurelio Cuniberti

Department of Chemistry: Faculty Publications

We demonstrate the functionalization of silicon nanowire based field effect transistors (SiNW FETs) FETs with stimuli-responsive polymer brushes of poly(N-isopropylacrylamide) (PNIPAAM) and poly(acrylic acid) (PAA). Surface functionalization was confirmed by atomic force microscopy, contact angle measurements, and verified electrically using a silicon nanowire based field effect transistor sensor device. For thermo-responsive PNIPAAM, the physicochemical properties (i.e., a reversible phase transition, wettability) were induced by crossing the lower critical solution temperature (LCST) of about 32 ◦C. Taking advantage of this property, osteosarcomic SaoS-2 cells were cultured on PNIPAAM-modified sensors at temperatures above the LCST, and completely detached by simply cooling. Next, …

Go to article

Rapid And Accurate Determination Of Atomistic Rna Dynamic Ensemble Models Using Nmr And Structure Prediction, Honglue Shi, Atul Rangadurai, Hala Abou Assi, Rohit Roy, David A. Case, Daniel Herschlag, Joseph D. Yesselman, Hashim M. Al-Hashimi Jan 2020

Rapid And Accurate Determination Of Atomistic Rna Dynamic Ensemble Models Using Nmr And Structure Prediction, Honglue Shi, Atul Rangadurai, Hala Abou Assi, Rohit Roy, David A. Case, Daniel Herschlag, Joseph D. Yesselman, Hashim M. Al-Hashimi

Department of Chemistry: Faculty Publications

Biomolecules form dynamic ensembles of many inter-converting conformations which are key for understanding how they fold and function. However, determining ensembles is challenging because the information required to specify atomic structures for thousands of conformations far exceeds that of experimental measurements. We addressed this data gap and dramatically simplified and accelerated RNA ensemble determination by using structure prediction tools that leverage the growing database of RNA structures to generate a con- formation library. Refinement of this library with NMR residual dipolar couplings provided an atomistic ensemble model for HIV-1 TAR, and the model accuracy was independently sup- ported by comparisons …

Go to article

A Luminescence-Based System For Identification Of Genetically Encodable Inhibitors Of Protein Aggregation, Travis J. Nelson, Shuo Liang, Cliff I. Stains Jan 2020

A Luminescence-Based System For Identification Of Genetically Encodable Inhibitors Of Protein Aggregation, Travis J. Nelson, Shuo Liang, Cliff I. Stains

Department of Chemistry: Faculty Publications

Molecules that disrupt protein aggregation represent potential tool compounds for the investigation of numerous human disease states. However, the identification of small molecules capable of disrupting protein aggregation has proven challenging. Larger biomolecules such as antibodies and proteins are promising alternatives due to their increased size. Despite the promise of protein-based inhibitors, generalizable assays are needed to more readily identify proteins capable of inhibiting aggregation. Herein, we utilize our previously reported self- assembling NanoLuc luciferase fragments to engineer a platform in which both detection reagents are expressed from the same plasmid, enabling facile co-transformation with a genetically encodable inhibitor. This …

Go to article

Constructing Stable And Potentially High-Performance Hybrid Organic-Inorganic Perovskites With “Unstable” Cations, Qing Yang, Menghao Wu, Xiao Cheng Zeng Jan 2020

Constructing Stable And Potentially High-Performance Hybrid Organic-Inorganic Perovskites With “Unstable” Cations, Qing Yang, Menghao Wu, Xiao Cheng Zeng

Department of Chemistry: Faculty Publications

A new family of functional hybrid organic-inorganic perovskites (HOIPs) is theoretically designed based on the following chemical+ insights: when a proton is adhered to molecules like water or ethanol, the newly formed larger-sized cations (e.g., H5O2 ,++ C2H5OH2 , and CH3SH ) entail low electron affinities mimicking superalkalis; they are conjugated acids of weak bases that cannot survive in solution, while their chemistry behavior in the HOIP frameworks, however, may be markedly different due to greatly enhanced cohesive energies of the proton, which facilitate the formation of new HOIPs. First-principles computations show that the putative formation reactions for these newly …

Go to article

Domain Wall Conduction In Calcium-Modified Lead Titanate For Polarization Tunable Photovoltaic Devices, Chong-Xin Qian, Hong-Jian Hong-Jian, Qiang Zhang, Jiawei He, Zi-Xuan Chen, Ming-Zi Wang, Xiao Cheng Zeng Jan 2020

Domain Wall Conduction In Calcium-Modified Lead Titanate For Polarization Tunable Photovoltaic Devices, Chong-Xin Qian, Hong-Jian Hong-Jian, Qiang Zhang, Jiawei He, Zi-Xuan Chen, Ming-Zi Wang, Xiao Cheng Zeng

Department of Chemistry: Faculty Publications

Ferroelectric domain wall (DW) conduction, confirmed in recent experiments, has attracted intense attention due to its promising applications in optoelec- tronic devices. Herein, we provide theoretical evidence of electric conduction in Pb0.8Ca0.2TiO3 (PCT) DWs. The separation of charge accumulation in DWs, corresponding to the electronic conduction-band minimum (CBM) and valence-band maximum (VBM), weakens the tendency for the electron-hole recombination, thereby providing more efficient channels for charge transfer. We fabricate PCT-based functional photovoltaic devices with polarization tunable charge transfer to exploit the combined conduction and ferroelectric properties of the DW. The photovoltaic performance of the devices can be regu- lated by …

Go to article

Mechanistic Insights Into The Acetate-Accelerated Synthesis Of Crystalline Ceria Nanoparticles, Tamra J Fisher, Deepa Choudhry, Kaitlynn Derr, Soodabeh Azadehranjbar, Dan Stasko, Chin Li Cheung Jan 2020

Mechanistic Insights Into The Acetate-Accelerated Synthesis Of Crystalline Ceria Nanoparticles, Tamra J Fisher, Deepa Choudhry, Kaitlynn Derr, Soodabeh Azadehranjbar, Dan Stasko, Chin Li Cheung

Department of Chemistry: Faculty Publications

Recent increasing uses of ceria in research and industrial applications have fostered continuing developments of efficient routes to synthesize the material. Here we report our investigation of the effects and the mechanistic roles of lithium acetate to accelerate the growth of crystalline ceria nanoparticles in ozone-mediated synthesis. By increasing the mole ratio of the acetate to cerium nitrate in the reactions, the reaction yields of ceria nanoparticles were observed to increase from ca. 10% to up to over 90% by cerium content in 30 min reactions. Microscopy images and Raman spectra of the assynthesized nanoparticles revealed that increasing the acetate …

Go to article

A Click-Based Modular Approach To Introduction Of Peroxides Onto Molecules And Nanostructures, Alissa Horn, Patrick H. Dussault Jan 2020

A Click-Based Modular Approach To Introduction Of Peroxides Onto Molecules And Nanostructures, Alissa Horn, Patrick H. Dussault

Department of Chemistry: Faculty Publications

Copper-promoted azide/alkyne cycloadditions (CuAAC) are explored as a tool for modular introduction of peroxides onto molecules and nanomaterials. Dialkyl peroxide-substituted alkynes undergo Cu(I)- promoted reaction with azides in either organic or biphasic media to furnish peroxide-substituted 1,2,3- triazoles. Heterolytic fragmentation of the peroxide to an aldehyde, a side reaction that appears to be related to the formation of the triazole, can be suppressed by use of excess alkyne, the presence of triethylsilane, or by use of iodoalkyne substrates. Complementary reactions of simple alkynes with azidosubstituted peroxides are much less efficient. Click reactions of alkynyl peroxyacetals are also reported; reductive fragmentation …

Go to article

Agbis2 As A Low-Cost And Eco-Friendly All-Inorganic Photovoltaic Material: Nanoscale Morphology– Property Relationship†, Ming-Gang Ju, Jun Dai, Liang Ma, Yuanyuan Zhou, Xiao Cheng Zeng Jan 2020

Agbis2 As A Low-Cost And Eco-Friendly All-Inorganic Photovoltaic Material: Nanoscale Morphology– Property Relationship†, Ming-Gang Ju, Jun Dai, Liang Ma, Yuanyuan Zhou, Xiao Cheng Zeng

Department of Chemistry: Faculty Publications

Solar cells made of low-cost solution-processed all-inorganic materials are a promising alternative to conventional solar cells made of high-temperature processed inorganic materials, especially because many high-temperature processed inorganic materials contain toxic element(s) such as lead or cadmium (e.g., CsPbI3 perovskite, PbS, CdTe and CdS(Se)). AgBiS2 nanocrystals, consisting of earth-abundant elements but without lead and cadmium, have already emerged as a promising candidate in highperformance solar cells. However, the nanoscale morphology–optoelectronic property relationship for AgBiS2 nanocrystals is still largely unknown. Herein, we investigate the electronic properties of various AgBiS2 nanocrystals by using first-principles computation. We show that …

Go to article

First Prev Next Last