Analytical Chemistry Commons^™

Enhancing The Photovoltaic Performance Of P3ht/Pdib Silsesquioxane Donor-Acceptor System Using Spray Deposition Fabrication Technique, Venkata Ramana Manda

Masters Theses & Specialist Projects

In the past few years, the solution-processed organic based solar cells gained more importance by meeting the demands for cost effective photovoltaic devices. To date, the focus of the organic photovoltaic devices has been on the optimization of the processing the materials to improve photo conversion efficiency and also by modifying the active components of the organic materials. Recently, it has been recognized that the deposition techniques also plays a major role in enhancing the power conversion efficiencies. Currently, though the most common deposition technique for organic solar cells is spin coating, which does not allow scaling up of the …

Synthesis Of Perylenediimide-Functionalized Silsesquioxane Nanostructures, Lan Xu

Masters Theses & Specialist Projects

Organic semiconductors functionalized nanostructures are becoming as promising materials for electronic device applications including organic photovoltaics (OPVs). Perylenediimide (PDI) derivatives have also been known as one of the best n-type organic semiconductors. PDI derivatives can form bulk materials, which are both photochemically and thermally stable and have been widely used in various optoelectronic devices. Due to the formation of high electron mobility of crystalline domains, they prefer to incorporate into a silsesquioxane network. Here, we describe the potential applicability of perylenediimide functionalized silsesquioxane nanoribbons (PDI-dimethyl nanoribbons) as an acceptor for optoelectronic devices. We have developed synthetic procedures to make the …

Laboratory Scale Study Of Calcium Sulfate Hydration Forms, Sandeep Kumar Kuthadi

Masters Theses & Specialist Projects

This research is part of an ongoing project to create gypsum wallboards with enhanced fire resistance. The main goal of this research is to better understand the dehydration properties of calcium sulfate dihydrate, and the hydration of calcium sulfate hemihydrate as well as anhydrous calcium sulfate. The lab-scale kinetics of these processes were studied using thermogravimetric analysis and sorption analysis. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used to characterize the products from different processes. In addition to the instrumental studies, small batches were handled in ovens and liquid slurries to better mimic the real world processing of …

The Analysis Of The Decomposition Of Hydrogen Peroxide Using A Schiff Base Copper Complex By Cyclic Voltammetry, Gavin James Rustin Mr.

Undergraduate Honors Theses

Copper(II) complexes of Schiff bases can be used in the catalysis of hydrogen peroxide to create water and oxygen. The mechanism and the kinetics of this disproportionation reaction by a dimeric copper(II) complex [CuSALAD]₂ are studied in this experiment, where SALAD refers to a Schiff Base ligand formed from salicyaldehyde and 1S,2S-D(+)-1-phenyl-2-amino-1,3-propanediol. By using cyclic voltammetry, the oxidation-reduction processes of a reaction may be monitored. The [CuSALAD]­₂ is initially reacted with a base such as imidazole to form the catalytic species, and the ratio of the copper(II) complex to the imidazole was found to be 1:4, consistent with …

Selective Oxidations By Metalloporphyrins And Metallocorroles, Tse-Hong Chen

Masters Theses & Specialist Projects

Highly reactive transition metal-oxo intermediates are important active oxidant involved in numerous enzymes such as cytochrome P450 monooxygenases as well as in many useful metal-catalyzed oxidations. Many transition metal catalysts are designed for biomimetic studies of the predominant oxidation catalysts in Nature, the cytochrome P450 enzymes. In this work, a series of metalloporphyrin and metallocorrole complexes have been successfully synthesized and spectroscopically characterized by UV-vis, GCMS and ¹H-NMR. The utilization of these complexes as catalysts for selective oxidation of sulfides and photocatalytic aerobic oxidations of activated hydrocarbons were investigated. Ruthenium(II) porphyrin complexes (2) and iron(III) corrole complexes (4) with …

Thermal Analysis Of Binding Of Organic Pollutants To Titanium Dioxide, Shashidhar Annarapu

Masters Theses & Specialist Projects

Conventional waste water treatment processes are not completely effective in removing highly stable organic compounds. Photocatalytic degradation on titanium dioxide is a possible alternative technique for many classes of these compounds. Several studies have been done by other researchers to study mechanisms of photocatalytic degradation, which occurs either through direct oxidation by holes or via indirect oxidation by radical messengers. Titanium dioxide can oxidize substrates directly through hole oxidation mechanisms or indirectly through free radical mechanisms. Substrates must bind onto the catalyst surface to undergo direct oxidation by holes. Thermogravimetric analysis (TGA) was performed on four different classes of compounds; …

Investigation Of Energy Alignment Models At Polymer Interfaces, Wenfeng Wang

USF Tampa Graduate Theses and Dissertations

The presented study investigated the Induced Density of Interface States (IDIS) model at different polymer interfaces by using photoemission spectroscopy in combination with electrospray deposition.

In recent years, organic electronics have attracted considerable attention due to their advantages of low-cost and easy-fabrication. The performance of such devices crucially depends on the energy barrier that controls the interface charge transfer. A significant effort has been made to explore the mechanisms that determine the direction and magnitude of charge transfer barriers in these devices. As a result of this effort, the IDIS model was developed to predict the energy alignment at metal/organic …

In Situ Detection On Electrochemical Chloride Removal Of Reinforcement In Concrete By Combined Ph/Cl- Probes, Jing-Jing Wang, Shi-Gang Dong, Xiao-Juan Zhang, Hong-Wei Lv, Yun-Chang Wu, Rong-Gui Du, Chang-Jian Lin

Journal of Electrochemistry

In this work, the concrete samples polluted by chloride ion were electrochemically treated using galvanostatic technique, and the distributions of chloride ion concentration and pH value in the polluted concretes were in-situ monitored by embedding a combined pH/Cl^- probe during the electrochemical chloride removal. The corrosion behaviors of reinforcing steel in the concrete were simultaneously studied by using linear polarization and electrochemical impedance spectroscopy techniques (EIS). The micro environment of the concrete and corrosion rate of steel were explored during the electrochemical chloride removal. It was indicated that the Cl^- concentration in the concrete pore solution decreased with …

Detection Of Glucosamine Hydrochloride By Ion Chromatography With Integrated Pulsed Amperometric Detector, Yan-Qun Fan, Qing-Yang Chen, Jin-Mei Xia, Jian-Zhong Xu, Xun Xu, Chen Xu

Journal of Electrochemistry

Factors (integral potential, concentration of NaOH and flow rate) affecting detection of Glucosamine hydrochloride by ion chromatography with integrated pulsed amperometric detector were studied. As the integral potential increased, the detection signal first increased and then decreased, while the detection background and noise increased directly. The suitable integral potential should be 0.1 V. With the concentration of NaOH increased, the retention time descended sharply, while the integral area increased quickly before they are coming back into balance. The number of theoretical plates increased firstly and then decreased. The optimum concentration of NaOH was 50 mmol·L^-1. As the flow …

Preparation Of A New Laccase Biosensor Based On Bimetallic Pt/Au Particles And Chitosan/Silica Sol-Gel Hybrid Films For Determination Of Catechol, Tong-Fang Lou, Jian-Ying Qu, Huan-Huan Xing, Xue-Ping Du, Ying Dong

Journal of Electrochemistry

A novel laccase (Lac) biosensor was fabricated successfully by means of entrapping Lac into bimetallic Pt/Au particles and chitosan/silica (CS-SiO₂) sol-gel hybrid films, and then applied to determine catechol (CC) concentration. The experiment results showed that the biosensor can electrocatalyze the reduction of CC, and the peak current increased linearly with the concentration of CC in the range of 8×10^-7 ~ 1×10^-4 mol·L^-1 (r = 0.9993) with a detection limit of 7.9×10^-8 mol·L^-1 by cyclic voltammetric response. The biosensor exhibited good sensitivity, stability and reproducibility, with a broad linear range for potential applications.

The Determination Of Mercury Levels In Aquatic Avian Populations Using Atomic Spectroscopy Techniques, Peter M. Klaeser

All Capstone Projects

Mercury contamination has been shown to have a negative impact in fish-eating birds, including impacts on behavior, reproductive success, and their overall survival. Higher than normal mercury levels have been detected in birds who depend on fish for their food. High levels of mercury have been detected in the bird’s blood and feathers using analytical techniques. The present accepted method of determining levels of mercury in feathers and blood is the use of atomic spectroscopy. The amount of mercury in feathers appears to depend on the growth of the feathers with more growth associated with lower levels of mercury contamination. …

Method Development And Analysis For Pharmaceuticals And Personal Care Products In Surface Water, Victoria Ruelas

All Capstone Projects

Pharmaceuticals and Personal Care Products (PPCP) in surface waters is a worldwide concern. Effluent from waste water treatment plants have tested positive for PPCP. Method development for a liquid chromatographic method was derived using columns with fused core technology. Analysis of spiked samples as direct injection and after solid phase extraction indicated detection of acetaminophen, caffeine, bisphenol-A and triclosan. Confirmation of acetaminophen, caffeine, bisphenol-A and triclosan was achieved using Agilent 1100 HPLC with Agilent MST Trap XCT. Solid phase extraction using Oasis HLB indicated reproducibility at 0.05ppm.

Protein Affinity Extraction Of Prostate Specific Antigen (Psa) Using Submicron Spheres, Yao Wang

Open Access Theses

PSA has been used as a biomarker for prostate cancer for a long time. To characterize different glycoforms of PSA using techniques like UHPLC and cIEF, concentration and purification of PSA from complex samples becomes necessary. Our group has developed submicron silica spheres based affinity beads to extract PSA through immunoprecipitation. This study focuses on measuring the bead performance when antibody type/amount was varied and PSA concentration was lowered for clinical use. To better satisfy the requirement of large-scale extraction, several attempts were made to increase the bead capacity. The results will be presented and future directions of the project …

Reactivity Studies Of Tridhydropyridine Radical Cautions By Using Fourier-Transform Ion Cyclotron Resonance Mass Spectrometry And Advancement Of Mass Spectrometric Analysis Of Asphaltenes And Degradation Products, Mohammad Sabir Aqueel

Open Access Dissertations

Aromatic organic molecules which have unpaired electrons play an important role in a variety of applications in the fields of organic synthesis, organic magnets, and biological activity of organic compounds. Several studies have been published on σ- type carbon-centered mono- and biradicals. Reactive intermediates with three formally unpaired electrons are known as triradicals. They can be defined as species with three electrons distributed in three degenerate or nearly degenerate orbitals, based on Salem's definition of biradicals from the electronic structure point of view. Very little is known about the reactivity of carbon-centered σ,σ,σ- triradicals due to the complexity of studying …

Design And Development Of A Novel Glucose Biosensor Based On The Ferrocene-Functionalized Fe3O4 Nanoparticles/Carbon Nanotubes/Chitosan Nanocomposite Film Modified Electrode, Hua-Ping Peng, Dai-Jun Zha, Wei Chen, Ai-Lin Liu, Xin-Hua Lin

Journal of Electrochemistry

A novel platform for the fabrication of glucose biosensor was successfully constructed by entrapping glucose oxidase (GOD) in a ferrocene monocarboxylic acid-aminated Fe₃O₄ magnetic nanoparticles conjugate (FMC-AFNPs)/chitosan (CS)/multiwall carbon nanotubes (MWNTs) nanocomposite. The formation of FMC-AFNPs could effectively prevent the leakage of ferrocene and retain its electrochemical activity. This GOD/FMC-AFNPs/CS/MWNTs matrix provided a biocompatible microenvironment for retaining the native activity of the immobilized GOD. Moreover, the presence of MWNTs enhanced the charge-transport properties of the composite and facilitated electron transfer between the GOD and the electrode for the electrocatalysis of glucose. Under the optimal conditions the designed …

A New Nonenzymatic Glucose Sensor Based On The Cuo Nanoplatelets, Yan-Cai Li, Fu-Ying Huang, Shun-Xing Li, Jie Chen, Shu-Qing Feng, Fei Wang

Journal of Electrochemistry

The CuO nanoplatelets were synthesized by hydrothermal method. The structure and morphology of the CuO nanoplatelets were characterized by TEM and XRD. A new nonenzymatic glucose sensor was constructed by immobilizing the CuO nanoplatelets on glassy carbon electrode with Nafion. The electrochemical performance of the CuO/Nafion/GCE for the detection of glucose was investigated by cyclic voltammetry and current-time curve. The experiment results showed that the linear dependence of the sensor was 0.01 to 0.3 mmol·L^-1 for glucose with a sensitivity of 1783.58 μA·mmol^-1·L·cm^-2, and the detection limit of the sensor was 0.80 μmol·L^-1 (S/N …

A Non-Equilibrium Approach To Temperature Calibration For Tungsten Filament Atomic Spectrometry, Edward C. Navarre, Paige Wallace

SIUE Faculty Research, Scholarship, and Creative Activity

A nonequilibrium approach to voltamperometric temperature measurement for tungsten filament atomizers was developed to facilitate the transfer of thermal conditions between instruments that possess different power supply regulation modes and filaments. Large differences in the equilibrium and instantaneous temperatures were found during the pyrolysis and atomization steps of cadmium atomic absorption spectroscopy (AAS) analysis. By using the instantaneous temperature, the pyrolysis and atomization behaviors of cadmium were shown to be equivalent regardless of the power supply regulation mode. The pyrolysis conditions optimized for a 15-V filament were readily and accurately transferred to a 12-V filament by applying the nonequilibrium voltamperometric …

Investigation And Characterization Of Pt-Modified Au Catalysts And Polymer Composites By Electrochemistry, Raman And Surface Enhanced Raman Spectroscopy (Sers), Ranjani Muralidharan

USF Tampa Graduate Theses and Dissertations

This dissertation thesis consists of six chapters. The main focus of this study is the need for understanding the reaction mechanism and intermediates formed on Pt-modified Au surface as anode catalysts in the formic acid fuel cells. Chapter 1 gives an introduction to formic acid and methanol fuel cells, an overview of the current catalysts employed at the anode of the fuel cells, specifically the Pt-modified Au electrodes as potential catalysts and the different deposition methods for preparing this catalytic surface. Information about different electrochemical methods used like cyclic voltammetry and potential step method along with other characterization methods and …

Simultaneous High-Performance Liquid Chromatography-Tandem Mass Spectrometry (Hplc-Ms-Ms) Analysis Of Cyanide And Thiocyanate From Swine Plasma, Raj K. Bhandari, Erica Manandhar, Robert P. Oda, Gary A. Rockwood, Brian A. Logue

Chemistry and Biochemistry Faculty Publications

An analytical procedure for the simultaneous determination of cyanide and thiocyanate in swine plasma was developed and validated. Cyanide and thiocyanate were simultaneously analyzed by high-performance liquid chromatography tandem mass spectrometry in negative ionization mode after rapid and simple sample preparation. Isotopically labeled internal standards, Na¹³C¹⁵N and NaS¹³C¹⁵N, were mixed with swine plasma (spiked and nonspiked), proteins were precipitated with acetone, the samples were centrifuged, and the supernatant was removed and dried. The dried samples were reconstituted in 10 mM ammonium formate. Cyanide was reacted with naphthalene-2,3-dicarboxaldehyde and taurine to form N-substituted …

Investigation Into The Cellular Actions Of Carnosine And C-Peptide, Emma H. Gardner

Theses, Dissertations and Capstones

Carnosine is a dipeptide composed of beta-alanine and histidine found exclusively in long-lived animal tissues. The cellular action of carnosine is still under extensive investigation; however, it has been proposed to have a role as an anti-oxidant and oxygen free radical scavenger, a physiological buffer, a heavy metal chelator, and has been implicated as an anti-aging agent.^2,4 Our lab has been studying the interaction between carnosine and heme by analyzing both the effect carnosine has on the glycation of the heme containing protein cytochrome c and the interaction of carnosine with free hemin. We have observed that the addition …