Physical Sciences and Mathematics Commons^™

Studies On The Mechanism By Which The Formation Of Nanocomposites Enhance Thermal Stability, Jin Zhu, Fawn Marie Uhl, Alexander B. Morgan, Charles A. Wilkie

Chemistry Faculty Research and Publications

Polystyrene−clay and polystyrene−graphite nanocomposites have been prepared and used to explore the process by which the presence of clay or graphite in a nanocomposite enhances the thermal stability of polymers. This study has been designed to determine if the presence of paramagnetic iron in the matrix can result in radical trapping and thus enhance thermal stability. Nanocomposites were prepared by bulk polymerization using both iron-containing and iron-depleted clays and graphites, and they were characterized by X-ray diffraction, transmission electron microscopy, thermogravimetric analysis, and cone calorimetry. The presence of structural iron, rather than that present as an impurity, significantly increases the …

Fire Retardancy In 2001, Gordon L. Wilson, Charles A. Wilkie

Chemistry Faculty Research and Publications

Fire is a world-wide problem which claims lives and causes significant loss of property. Some of the problems are discussed and the solution delineated. This peer-reviewed volume is designed to be as the state-of-the-art. This chapter provides a perspective for current work.

Self-Assembly Of A Bis-Urea Macrocycle Into A Columnar Nanotube, Linda S. Shimizu, Mark D. Smith, A. D. Hughes, Ken D. Shimizu

Faculty Publications

A bis-urea macrocycle 1 was synthesized and shown to form extended nanotubular columns byX-ray crystallography.

Boron-Doped Homoepitaxial Diamond (100) Film Investigated By Scanning Tunneling Microscopy, Bing Xiao, Weihai Fu, Sacharia Albin, Jason Moulton, John Cooper

Electrical & Computer Engineering Faculty Publications

Conducting epitaxial diamond films of high quality are essential for many diamond studies and diamond electronic device fabrication. We have grown boron-doped epitaxial diamond films on type Ila natural diamond (100) substrates by microwave plasma chemical vapor deposition. A gas mixture of H₂/CH₄ was used. Boron doping was done by placing solid sources of pure boron in the microwave plasma. Homoepitaxial films with atomic smoothness were achieved under the following growth conditions: substrate temperature 900 °C, gas pressure 40 Torr, and gas flow rates of H₂/CH₄ = 900/7.2 seem. The growth rate was 0.87 …

Effect Of Circular Motion Exercise On Bone Modeling And Bone Mass In Young Rats: An Animal Model Of Isometric Exercise, Jodi F. Evans Ph.D., J. K. Yeh, Q. Niu, J. Iwamoto, J. F. Aloia

Faculty Works: BCES (1999-2023)

The aims of the study are to develop a non-invasive animal model of circular motion exercise and to evaluate the effect of this type of exercise on bone turnover in young rats. The circular motion exercise simulates isometric exercise using an orbital shaker that oscillates at a frequency of 50 Hz and is capable of speeds from 0-400 rpm. A cage is fixed on top of the shaker and the animals are placed inside. When the shaker is turned on, the oscillatory movement should encourage the animals to hold on to the cage and use various muscle forces to stabilize …

Synthesis And Analysis Of Three-Dimensional Molecular Architectures, Patricia Beck

LSU Master's Theses

The use of resorcinarenes in the study of biologically significant phenomena has been the focus of much attention, due to the versatility of these macrocyclic compounds. In this thesis, two applications of resorcinarenes are explored. First, the search for the mechanism by which tetraarylboronic acid resorcinarenes lead to colorimetric detection and quantization of saccharide analyte concentration in solution is described. Second, the extension of the lower rim conjugation of the resorcinarene macrocycle by the fourfold addition of various length oligo(p-phenylene) rods is discussed. The synthesis of these tubular materials, with potential uses as artificial ion channels and for binding and …

Characterizing And Monitoring Changes In State Of Polymers During Cure And Use -Aging, Andrew Orschel Meyer

Dissertations, Theses, and Masters Projects

Multi Angle Laser Light Scattering (MALLS) and Frequency Dependent Electromagnetic Sensing (FDEMS) provide unique characterizations of polymer systems during cure and use-aging. This research illustrates how MALLS is an extremely accurate technique for absolute characterization of macromolecules, giving molecular weight and size information that other widely used and accepted techniques are incapable of measuring. Application of MALLS to monitoring the changing state of a polyamide-11 system in a water aging environment led to the discovery of an equilibrium molecular weight which is the result of two competing reactions, hydrolysis-degradation and a newly discovered recombination-polymerization reaction. The discovery of this recombination …

The Coupling Of Biotechnology With Electrochemistry: Electrodenitrification Of Water Using The Enzyme Nitrate Reductase, Cyril Geyer

Dissertations and Theses @ UNI

Nitrate is a worldwide contaminant that causes environmental (eutrophication) and human health (methemoglobinemia, cancers) concerns. Very few techniques are available to eliminate it from natural environment and they suffer from major drawbacks, such as production of unwanted byproducts (toxins or brine). The electrochemical reduction of nitrate on any electrode is relatively slow and catalysts or electron mediators are needed. The goal of this project was to develop a new process that could overcome these disadvantages. The project demonstrates the feasibility of using an enzyme, nitrate reductase, and a mediator, methyl viologen to transfer the electrons from the electrode to nitrate, …

Analysis Of Inorganic Materials Using Advanced Nmr And Nqr Techniques, Anthony Adrian Mrse

LSU Doctoral Dissertations

Several advanced solid-state nuclear magnetic resonance (NMR) and nuclear quadrupole resonance (NQR) techniques have been applied to inorganic materials of commercial interest. The specific techniques applied to each system were chosen to solve specific obstacles which impeded the flow of industrial science.

First, the dispersion of brominated flame retardants in polymers is monitored using pulsed ⁸¹Br NQR (nuclear quadrupole resonance) techniques. The NQR spectrometer consists of a homemade NMR console and an automatically tuned loop-gap resonator probe. The two factors which affect the ⁸¹Br NQR transition frequencies of brominated aromatics are: electron-donating and withdrawing substituents on the ring …

Analysis Of Near-Infrared Dye-Labeled Sanger Sequencing Fragments With Gel Electrophoresis Using The Time-Resolved Flourescence Lifetime Indentification Methods, Suzanne Jeanel Lassiter

LSU Doctoral Dissertations

The research presented in this dissertation involves the identification of sequencing fragments with time-resolved methods. For this application, near-infrared heavy-atom tricarbocyanine dyes were developed in our laboratory, which can be excited with a single laser and emission collected using a single detection channel. The dyes have four spectroscopically unique, but relatively short lifetimes that can be altered by the intramolecular heavy-atom they contain. The work described here involves the optimization of dye-primer chemistry for preparing Sanger sequencing reactions for longer reads and the optimization of the separation matrix for capillary gel electrophoresis that produces favorable statistical analysis of the aforementioned …

Structure Determination Of Ba8Corh6O21, A New Member Of The 2h-Perovskite Related Oxides, Hans Conrad Zur Loye, M. D. Smith, K. E. Stitzer, A. El Abed, J. Darriet

Faculty Publications

Single crystals of Ba₈CoRh₆O₂₁ were grown out of a potassium carbonate flux. The structure was solved by a general method using the superspace group approach. The superspace group employed was R3m(00γ)0s with a = 10.0431(1) Å, c₁ = 2.5946(1) Å and c₂ = 4.5405(1) Å, V = 226.60(1) ų. Ba₈CoRh₆O₂₁ represents the first example of an m = 5, n = 3 member of the A_3n+3mA'_nB_3m+nO_9m+6n family of 2H hexagonal perovskite related oxides and contains chains consisting of six …

Pentacarbonyl Derivatives Of Polydentate Phosphines, Yi Zang

Masters Theses

Four phosphines (Ph₂P)₂C=CHPPh₂, (p-tol)₂PCH₂P(p-tol)₂, (o-tol)₂PCH₂P(o-tol)₂, Ph₂PCH₂P(p-tol)₂ and their pentacarbonyltungsten complexes have been prepared and studied as part of a continuous investigation of polydentate phosphines that are coordinated as monodentate ligands. The ligand, (Ph₂P)₂C=CHPPh₂, was prepared by base-catalyzed addition of Ph₂PH to Ph₂PC=CPPh₂. Reaction of this ligand with (OC)₅WNH₂Ph led to formation …

The Synthesis Of 2-Indenylphenols: Potential Ligands For Transition Metals, Yoon Jae Kim

Masters Theses

The syntheses of 2-(2-indenyl)-phenol and 2-(1-indenyl)-phenol via a three-step sequence have been developed. In the first steps of the sequence, a Grignard reagent formed from 2-iodoanisole or 2-bromoanisole reacted with 1-indanone or 2-indanone in yields that ranged from 11.3% to 67.2%. The second step consisted of acid-catalyzed dehydration of the alcohol formed in step 1 to make a 2-inenyl anisole; yields in the second step were 45.2% to nearly quantitative. Finally, demethylation of the 2-indenyl anisole was achieved with AlBr₃ in ethanethiol in yields ranging from 52.9% to 0 %. Each product was characterized by ¹H and ^{13 …}

Computational Studies Of Regularities In Bond Dissociation Enthalpies And Interactions Of Acetylthiocholine With Solvent Molecules, Wencui Zheng

Masters Theses

This thesis reports the results of two different research projects. One project is an evaluation of the feasibility of applying constant bond dissociation enthalpy ratios to neutral molecules for which one atom is from group 13 or group 17 and the other atom is from group 16. The other project attempts to validate the proposal that the aromatic residues lining the acetylcholinesterase (AChE) gorge will induce entry of acetylthiocholine (ATCh) into the gorge in a manner similar to that of the neural transmitter acetylcholine.

A total of thirty AB₂ and AB molecules have been examined, where A = B, …

The Reactivity Of Boron And Aluminum Compounds With Silica Gel Surfaces, Jeannine M. Christensen

Masters Theses

The unmodified silica gel surface contains isolated silanols, vicinal silanols, and siloxane species. Silica gels can be thermally and/or chemically treated to obtain a desired surface. Hexamethyldisilazane (HMDS) was used to chemically modify the silica gel to obtain a surface that contains vicinal silanol groups and siloxane species. The silica gel was thermally treated at 600°C to create a surface that contains isolated silanols and siloxane species. Four types of silica gels (unmodified, 600°C, HMDS and 600°C/HMDS) were reacted with three boron compounds. The boron compounds used were boron trichloride (BCl₃), triethyl borane (B(CH₂CH₃) …

Solid State Nmr Characterization Of Structural And Motional Parameter Distributions In Polyamidoammonium Dendrimers, Dariya Ivanovna Malyarenko

Dissertations, Theses, and Masters Projects

The characterization of narrow distributions of structural and motional parameters, and their evolution during the broad glass transition, is performed for deuterated PAMAM dendrimer salts using solid state NMR. The broadening of deuteron quadrupole echo (QE) lineshapes is consistent with the presence of narrow hydrogen bond length distribution (sigmar < 0.25 A) at the spacer amide and branching tertiary amine sites. The temperature dependent averaging of the experimental lineshapes is explained on the basis of fast planar librations in the dendrimer interior, and fast rotation and intermediate regime libration (in an asymmetric cone) of the dendrimer termini. The amplitudes of libration are temperature dependent and higher for low generation dendrimers, while librational rates show Arrhenius behavior only within the glass transition region. In this region, the width of log-normal distribution of rates increases with temperature at sites associated with chlorine counterions. The largest distributions are still less than one order of magnitude wide, unlike the dendrimer in solution or the linear polymers. Interpenetrated low generations (G < 3), uniform intermediate generations (G = 3--5) with surface network, and backfolded high generations (G > 5), are distinguished by interior and termini dynamics.;In the regime of fast motion QE lineshapes are highly sensitive to the presence of narrow structural and motional parameter distributions, and provide constraints on motional geometry independent of rates. The precise characterization of narrow log-normal rate distributions in the intermediate regime can be …

Characterization Of Lipids And Fatty Acid Methyl Ester Contents In Leaves And Roots Of Crocus Vallicola, Nuretti̇n Yayli, Zerri̇n Kiran, Hasan Seymen, Hasan Genç, Mustafa Küçüki̇slamoğlu

Turkish Journal of Chemistry

The chemical composition of the fatty acids methyl esters (FAMEs) and other lipids in leaves and roots of Crocusvallicola were analyzed by gas chromatography-mass spectrometry(GC-MS). In this work, twenty-eight compounds, including 22 FAMEs, 1 aldehyde, 3 hydrocarbons (substitute alkane and alkene), 2 alcohols in the leaves and twenty-one compounds (17 FAMEs, 1 anhydride, 1 substitute alcohol, 1 ketone, 1 substitute amide) in the roots were identified by GC-MS from C. vallicola. The FAMEs in leaves and roots were highly similar; only the amounts of the esters were different. Key Words: Crocus vallicola, leaves, roots, FAMEs

Effect Of Acid Treatment On Volumetric Swelling Ratios Of Coals, Nejat Mesci̇, Aki̇f Şenelt, Taner Toğrul, Aral Olcay

Turkish Journal of Chemistry

To remove Ca^{2+} ions, six low rank coals and one coking coal were treated with 0.1 and l.0 N HC1 for 24 h. IR spectra and proximate analysis of the lignites indicated that only slight structural changes had occurred during acid treatment. The swelling ratios of parent and acid-treated coal samples showed that removal of Ca^{2+} resulted in an increase in the swelling ratios. Higher swelling ratios were obtained with acid-washed coal samples. While the highest swelling ratios of the parent lignites were obtained in ethylenediamine, those of acid-treated samples were obtained in pyridine and dimethylformamide.

Calculation Of Multi-Center Integrals For The Region Of Moderate And Weak Overlap, Abdulhali̇k Karabulut, Gökhan Budak, Lütfü Demi̇r, Nagi̇f Sefteroğlu Nabi̇yev, Yusuf Şahi̇n

Turkish Journal of Chemistry

In this study a general formula was established for multi-center integrals over Gaussian basis sets using the two-center expansion of nuclear attraction and electron repulsion potentials. The terms of the formula are the analytical functions of interatomic distances. Three kinds of integrals contained in these formulae can be evaluated analytically. In the presented method, unlike many other popular methods, the numerical integrations procedure is unnecessary since it does not contain the incomplete gamma function. A computer program was written and tested for various orbitals. The calculations show that the series converge very rapidly.

Propylene Dimerization Over Nickel-Ion Exchanged Zeolites In The Liquid Phase, Mina K. Munshieva

Turkish Journal of Chemistry

The possibility of the dimerization of propylene in the liquid phase over nickel-ion exchanged zeolites (Ni-zeolites) modified by treatment with AlEt_{2}Cl to provide enhanced activity is studied. In order to determine the influence of the crystalline structure of zeolites on their catalytic activity and the selection of the most active catalyst the zeolites of faujasite (NaX, NaY), eryonite and mordenite types with various structures and different cell sizes have been chosen. The samples of Ni-zeolites were prepared by ion exchange with nickel nitrate in a corresponding zeolite. The treatment of these zeolites with AlEt_{2}Cl leads to the formation of active …

Hydrothermal And Microwave Synthesis Of Boron Phosphate, Bpo_{4}, A. Baykal, Meral Kizilyalli, M. Toprak, R. Kniep

Turkish Journal of Chemistry

BPO_4 was previously synthesized by the solid state reactions of (NH_4)_2HPO_4 and B_2O_3 at 1000 ^oC and was characterized by X-ray powder diffraction and IR methods. We have now succeeded in preparing BPO_4 from H_3BO_3 and P_2O_5 using hydrothermal synthesis by heating at 160 ^oC for 2 days and obtained a single phase product. We observed that a microwave-assisted synthesis takes only 3 to 5 minutes to transform a solid mixture of (NH_4)_2B_4O_7.4H_2O, and solid H_3PO_4 or B_2O_3 + P_2O_5 into the crystalline title compound. Its X-ray powder diffraction data and IR spectra were in good agreement with the literature …

The Influence Of Transition Metal Ions On The Kinetics Of Ascorbic Acid Oxidation By Methylene Blue In Strongly Acidic Media, M. Nasiruddin Khan, Anila Sarwar

Turkish Journal of Chemistry

The kinetics of the oxidation of L-ascorbic acid (H_{2} A) by methylene blue was investigated in strongly acidic media over the temperature range 22-40 ^oC. The kinetic studies were carried out as a function of different variables like concentration, pH, ionic strength and temperature. The rate was found to be a linear relation with [H_{2} A], [M.B.] and [H^{+}]. Ionic strength dependence formation indicated complex formation by monocationic and anionic species in solution. The reaction rate was greatly catalyzed by the presence of trace amounts of copper (II) ion. Possible mechanisms for the catalyzed and uncatalyzed reactions are proposed. Kinetic …

Synthesis Of Azobenzo[B]Thiophene Derivatives And Their Dyeing Performance On Polyester Fibre, Hari Raghav Maradiya

Turkish Journal of Chemistry

Ethyl 2-amino-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxylate was synthesised by the reaction of cyclohexanone and sulphur with ethylcyanoacetate. The 2-aminothiophene derivative was diazotised and coupled with various N-arylmaleimides to give monoazo disperse dyes. The dyeing performance of these dyes was assessed on polyester fabric. These dyes were found to give light pink to reddish pink shades with very good depth and levelness on polyester fabric. The dyed fabric showed fair light fastness and excellent washing, rubbing, perspiration and sublimation fastness. The dyebath exhaustion on polyester fabric was found to be good and acceptable.

Purification And Partial Characterisation Of Superoxide Dismutase From Chicken Erythrocytes, Tüli̇n Aydemi̇r, Leman Tarhan

Turkish Journal of Chemistry

Superoxide dismutase (SOD), which plays a very important role in protecting organisms from oxygen toxicity, was purified from chicken erythrocyte and partially characterised. Erythrocyte membranes were disintegrated via freeze-thaw methods in the presence of Triton X-100. Following ethanol precipitation, SOD-containing solution was applied to DEAE-cellulose and then Sephadex G-100 gel columns. Chicken erythrocyte SOD was purified 508-fold with a specific activity of 8,480 units per mg. The molecular weight was estimated to be 30.6 kDa \pm 0.4 by gel filtration. The enzyme was composed of two subunits of equal size and contained one atom of copper and one atom of …

Study Of The Effect Of Number Of Layers On The Electrosynthesis Of Cobalt(Iii) Acetate In A Bipolar Packed-Bed Flow Reactor, Altan Güvenç, Belgi̇n Karabacakoğlu

Turkish Journal of Chemistry

Cobalt(III) acetate, which is an important oxidizing agent and catalyst in organic reactions, was electrosynthesized from cobalt(II) acetate solution in a bipolar packed-bed flow reactor. In order to determine the effect of the number of layers on the yield of cobalt(III) acetate, experiments were performed in three different lengths of bipolar electrode cells, namely 16, 29 and 55 layers of graphite Raschig rings. The experiments were carried out at controlled potentials of 50-450 V, measuring the total current and using the solution (5% H_{2}O, 95% CH_{3}COOH, 0.06MCo(CH_{3}COO)_{2}.4H_{2}O, 0.2M CH_{3}COONa.3H_{2}O) at 298 K and 0.133 L.h^{-1} flow rate. According to the …

Voltammetry Of The Anticancer Drug Mitoxantrone And Dna, Arzum Erdem, Mehmet Özsöz

Turkish Journal of Chemistry

The interaction of mitoxantrone (MTX) with calf thymus double-stranded DNA (dsDNA) and calf thymus single-stranded DNA (ssDNA) was studied electrochemically by using differential pulse voltammetry (DPV) and cyclic voltammetry (CV) at a carbon paste electrode (CPE). The changes in the experimental parameters (the concentration of MTX, the concentration of DNA and the accumulation time of MTX) were studied by DPV; in addition, the detection limit and the reproducibility were determined. It was observed for the interaction of MTX with dsDNA and ssDNA that the signal of the bare electrode was higher than the signal of the dsDNA modified CPE. The …

Separation Process Of Citric Acid With Tertiary Amines/Diluents In Supercritical Co_{2}, Arzu Koparan, Afi̇fe Güvenç, Nurcan Kapucu, Ülkü Mehmetoğlu, Ayla Çalimli

Turkish Journal of Chemistry

Reactive extraction of citric acid was investigated at atmospheric and supercritical conditions. The most suitable diluent and amine from among the tertiary amines and eight different diluents were determined at atmospheric conditions. The distribution coefficient values obtained with Hostarex A 327 were higher than those of Alamine 336. The selected amine (Hostarex A327) and the diluent (Oleyl alcohol) were used for reactive extraction of citric acid at supercritical conditions. Separation yields of citric acid were obtained in the temperature ranges of 308 to 328 K and in the pressure ranges of 80 to 180 bars in a supercritical extraction system …

Spectrophotometric Determination Of Propranolol As Cu(Ii), Ni(Ii) And Co(Ii) Dithiocarbamate Complexes, Ayşegül Gölcü, Mustafa Dolaz, Selahatti̇n Seri̇n

Turkish Journal of Chemistry

A spectrophotometric method was developed for the determination of the beta adrenergic blocking drug propranolol. The method was based on the formation of Cu(II), Ni(II) and Co(II)-dithiocarbamate complexes from the secondary amine group of propranolol with carbondisulfide (CS_{2}) and the acetate salts of the metals in ammonia medium. The method was applied to the analysis of propranolol tablets and the results were statistically compared with those obtained by the official method using t- and F-tests. There was no significant difference between the mean values and the precisions of the two methods at the 95% confidence level.

Synthesis And Spectrophotometric Investigation Of A New Vic-Dioxime Ligand And Its Transition Metal Complexes, Mustafa Dolaz, Mehmet Tümer, Ayşegül Gölcü, Selahatti̇n Seri̇n

Turkish Journal of Chemistry

A new vic-dioxime ligand and its Cu(II), Co(II), Ni(II), Pd(II), VO(IV) and Zn(II) complexes have been prepared and characterized by elemental analyses, infrared, electronic spectra, magnetic moment and molar conductance data. The Ni(II), Pd(II) and Zn(II) complexes have a diamagnetic character. The ^{1}H- and ^{13}C-nmr and GC/MS spectra of the vic-dioxime ligand and its Ni(II), Pd(II) and Zn(II) complexes were recorded. In addition, all compounds are non-electrolyte.

Conductimetric And Potentiometric Titration Of Some Hydroxylated Cinnamic Acids With Tetrabutylammonium Hydroxide In Non-Aqueous Media, A.Hakan Aktaş, Gülsüm Yaşar, Güleren Özkan Alsancak, Şahi̇nde Demi̇rci̇

Turkish Journal of Chemistry

In this study, four hydroxycinnamic acids, namely 3,4-dihydroxycinnamic acid, 4-hydroxycinnamic acid, 4-hydroxy --3- methoxycinnamic acid and 4-hydroxy-3,5-dimethoxycinnamic acid, were titrated conductimetrically and potentiometrically using triethylamine and tetrabutylammonium hydroxide in acetonitrile, 2-propanol, and pyridine solvents under a nitrogen atmosphere at 25 ^oC. In conductimetric titration with tetrabutylammonium hydroxide all of the compounds exhibited conventional stoichiometric titration curves in 2-propanol . As is evident from the titration curves, all these compounds gave two well-defined end points. The first end point corresponds to exactly one equivalent and the second one to the two equivalents of the base. In conductimetric titration with tetrabutylammonium hydroxide, …