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Full-Text Articles in Chemistry

Synthesis Of Poly(Styrene-Co-Butyl Acrylate) Pickering Emulsion With Montmorillonite Nanoparticles And Its Comparison With Sodium Dodecyl Sulfate Surfactant On Affecting The Water Barrier Properties Of Coated Paper, Chidubem H. Uchefuna Dec 2023

Synthesis Of Poly(Styrene-Co-Butyl Acrylate) Pickering Emulsion With Montmorillonite Nanoparticles And Its Comparison With Sodium Dodecyl Sulfate Surfactant On Affecting The Water Barrier Properties Of Coated Paper, Chidubem H. Uchefuna

Electronic Theses and Dissertations

Water-borne barrier dispersion coatings on paper have emerged as an alternative to extrusion coatings on paper due to improved recycling, high application speed, and other end of life attributes. Pigments are often added to improve the performance of dispersion coatings. The use of pigments to form a Pickering emulsion during the polymerization step for the production of a barrier coating on paper has not been discussed in the literature.

In this study, montmorillonite (MMT) pigment varied from 0-6 % pigment volume concentration (PVC) was used to synthesize dispersion coatings consisting of poly(styrene-co-butylacrylate) latex and compared with sodium dodecyl …


Expanding The Polymer Zwitterion Library – Novel Phosphonium-Based Polymer Zwitterions And Analogous Structures, Marcel U. Brown Oct 2022

Expanding The Polymer Zwitterion Library – Novel Phosphonium-Based Polymer Zwitterions And Analogous Structures, Marcel U. Brown

Doctoral Dissertations

This dissertation encompasses the synthesis, characterization and application of novel polymer zwitterions that significantly expand the library of available zwitterionic polymers. Their facile synthesis is facilitated by the preparation of a novel functional sultone precursor molecule, which can be ring-opened by commercially available phosphine, amine and sulfide nucleophiles, affording phosphonium, ammonium or sulfonium sulfonate monomers, respectively. Most notably, this work describes the invention of phosphonium-based polymer zwitterions, establishing a new class of zwitterionic polymer structures with unique solution and interfacial properties. Furthermore, the incorporation of these phosphonium sulfonates into block copolymer architectures with conventional polymer zwitterions, and the resulting switchable …


Reinforcement Of Elastomers By Reactive Ionic Surfactant, Nicole Vickerman Jan 2022

Reinforcement Of Elastomers By Reactive Ionic Surfactant, Nicole Vickerman

Williams Honors College, Honors Research Projects

Elastomers without cross-linking agents or fillers do not have the necessary properties for practical applications in the rubber industry. Elastomers must be reinforced with fillers and/or cross-linking agents to achieve the needs of physical and mechanical properties for commercial products. Sodium octyl 6-mercaptohexyl phosphate (SOMP) and sodium ethyl (6-mercaptohexyl) phosphate (SEMP) were used to investigate the influence of a reactive ionic surfactant and its influence on the physical properties of peroxide crosslinked styrene butadiene rubber (SBR). SEMP and SOMP were both found to be able to be grafted successfully on to the SBR chains within the rubber using extraction testing …


Characterization Of Lamellar Liquid Crystal Emulsifiers In Topical Creams Containing A Novel Solvent, Melinda Joanna Sutton Aug 2021

Characterization Of Lamellar Liquid Crystal Emulsifiers In Topical Creams Containing A Novel Solvent, Melinda Joanna Sutton

MSU Graduate Theses

Diethylene glycol monoethyl ether (DEGEE) is a promising solvent component in topical cream formulations due to its superior solubilizing abilities with certain active pharmaceutical ingredients. One of the goals of this study is to characterize the effects of pH on the physical and chemical stabilities of topical cream formulations containing particularly high concentrations of DEGEE by characterizing a full topical pH profile of 3.5 – 9.0. The second goal is to evaluate the presence, amount, and characteristics of lyotropic liquid crystals (LLCs), molecularly structured in a lamellar phase, in a model cream emulsion utilizing polarized light microscopy (PLM). The presence …


Electrochemical Evaluation Of The Desloratadine At Bismuth Film Electrode In The Presence Of Cationic Surfactant: Highly Sensitive Determination In Pharmaceuticals And Human Urine By Linear Sweep-Cathodic Stripping Voltammetry, Yalçin Altunkaynak, Günay Önal, Abdulkadi̇r Levent Jan 2021

Electrochemical Evaluation Of The Desloratadine At Bismuth Film Electrode In The Presence Of Cationic Surfactant: Highly Sensitive Determination In Pharmaceuticals And Human Urine By Linear Sweep-Cathodic Stripping Voltammetry, Yalçin Altunkaynak, Günay Önal, Abdulkadi̇r Levent

Turkish Journal of Chemistry

In this study, the electrochemical properties of desloratadine, which is in the second generation antihistamines group, were determined by bismuth film electrode (BiFE) in aqueous and aqueous/surfactant solutions. This compound gave an irreversible and diffusion-controlled reduction peak at about -1.65 V by cyclic voltammetry. It was found that the addition of cationic surfactants (cetyltrimethylammonium bromide (CTAB) increased the reduction current signal of desloratadine, while anionic (sodium dodecylsulfate (SDS) and nonionic (Tween 80) surfactants were found to have an adverse effect. Using linear sweep-cathodic stripping voltammetry, the analytical signal showed a linear correlation with a concentration of 0.1 to 4 μM …


Self-Immolative Polymers As A Degradable And Triggerable Class Of Surfactants, Siamak Keshtpour Nov 2020

Self-Immolative Polymers As A Degradable And Triggerable Class Of Surfactants, Siamak Keshtpour

Electronic Thesis and Dissertation Repository

Self-immolative polymers (SIPs) are degradable polymers that undergo end-to-end depolymerization upon triggering. They have potential for the development of degradable surfactants addressing human and environmental toxicity concerns associated with non-degradable surfactants, but they have not yet been investigated as surfactants. Herein, polyglyoxylamide SIPs with different pendent groups and end-caps were synthesized, envisioning they could serve as depolymerizable analogues of poly(vinyl alcohol) and its derivatives. Polyglyoxylamides with pendent hydroxyls stabilized both PEA and PLA particle suspensions. They showed the potential to undergo triggered degradation, resulting in destabilization of the suspensions. However, untriggered suspensions exhibited poor long-term stability, so further structural tuning …


Rheological Studies Of Fully-Formulated Coatings Thickened With Heur: Effects Of Surfactants, Brandon M. Bonilla Sep 2020

Rheological Studies Of Fully-Formulated Coatings Thickened With Heur: Effects Of Surfactants, Brandon M. Bonilla

Master's Theses

Rheology modifiers such as hydrophobically-modified ethoxylated urethane (HEUR)thickeners are included in waterborne latex coatings to optimize shear-rate dependent viscosity and other rheological properties. While these HEUR polymers are commonly used in industry, the complex chemical interactions that contribute to rheological properties are still not completely understood. Prior work in this area has focused on understanding latex-HEUR and latex-surfactant-HEUR interactions that affect rheological properties. Additionally, studies have been previously conducted to understand the relaxation mechanisms of complex interactions present in HEUR-thickened waterborne latex coatings under various dynamic conditions. The objective of this work is to extend the experimental work to fully-formulated …


Effect Of Surfactant Types On Particle Size And Morphology Of Flame-Retardantzinc Borate Powder, Yeli̇z İpek Jan 2020

Effect Of Surfactant Types On Particle Size And Morphology Of Flame-Retardantzinc Borate Powder, Yeli̇z İpek

Turkish Journal of Chemistry

Zinc borate is a boron-containing chemical material that is used to increase the flame retardancy of polymeric materials, dyes, cables, fabrics, carpets, and the internal parts of automobiles and planes. Commercially used zinc borate, which has the formula of 2ZnO· 3B$_{2}$ O$_{3}$· 7H$_{2}$ O, has a particle size between 10 and 20 μm. However, recent studies have shown that nanosized flame retardants have more superior flame retardancy and less negative effects on mechanical properties than microsized flame retardants. Nanosized flame retardants disperse more homogeneously and even low quantities are sufficient to provide high flame resistance. In this study, nano zinc …


Beam Loss Analysis Through Particle Tracking Simulation, Marvin Valverde Sep 2019

Beam Loss Analysis Through Particle Tracking Simulation, Marvin Valverde

STAR Program Research Presentations

Water soluble-polymers are commonly used to build detergents or other types of surfactants. These polymers are important because water soluble-polymers used in the development of surfactants have become an essential new factor in the cleaning of oil. However, the development of these surfactants has been constrained by the difficulty of producing them. For this synthesis, phenolic maleimide was used as starting material for a water-soluble polymer. This polymer will be able to break apart at set temperatures and self-assemble into a surfactant.


Rheological Investigations Of Latex-Surfactant-Associative Thickener Aqueous Systems, Bishop I. Hammack Jun 2019

Rheological Investigations Of Latex-Surfactant-Associative Thickener Aqueous Systems, Bishop I. Hammack

Master's Theses

Surfactants and Thickeners are both additives used in fully-formulated waterborne coatings to provide colloidal stability, thickening, and other functionality. The behavior of each ingredient in a coating must be understood and controlled to maintain colloidal stability as well as balance other desired properties of the liquid coating and the dry paint film. In this work, quaternary systems of Water-Latex-Thickener-Surfactant were investigated to further the understanding of their behavior in coatings. The thickener used was a well characterized, hydrophobically-modified, ethoxylated urethane (HEUR) with two C18 terminal hydrophobes and 795 average repeat units of ethylene oxide as the hydrophilic spacer. Two latexes, …


Synthesis Of Flower-Like Vanadium Disulfide For Lithium Storage Application, Pan Li, Jian Liu, Wei-Yi Sun, Hai-Xia Li, Zhan-Liang Tao Feb 2019

Synthesis Of Flower-Like Vanadium Disulfide For Lithium Storage Application, Pan Li, Jian Liu, Wei-Yi Sun, Hai-Xia Li, Zhan-Liang Tao

Journal of Electrochemistry

In order to improve the electrochemical properties of vanadium disulfide (VS2) as an electrode material in Li-ion battery, the flower-like VS2 was prepared by a one-step hydrothermal method with the addition of polyethylene glycol 400. The phase and morphology of the product were characterized by using X-ray diffraction and field emission scanning electron microscopy. During the growth process, it was observed that the flower-like VS2 was interspersed with several hexagonal vanadium disulfide nanosheets, which had a high specific surface area and excellent structural stability. The flower-like VS2 was used for the cathode material test in …


Multidimensional Mass Spectrometry Of Chemonic™ Ccg-6 Nonionic Surfactant With Separation By Polarity And Shape, Charles Johnson Jan 2019

Multidimensional Mass Spectrometry Of Chemonic™ Ccg-6 Nonionic Surfactant With Separation By Polarity And Shape, Charles Johnson

Williams Honors College, Honors Research Projects

Chemonic™ CCG-6 surfactant is a water-soluble poly(ethylene glycol) (PEG) conjugated alkyl glyceride emollient. This surfactant exists as a complex mixture of a glycerol cores conjugated with poly(ethylene glycol) branches (PEGylation) that were partially esterified with caprylic (C8) and capric (C10) acids. These may be esterified on one, two, or all three arms of the glyceride. The architecture of the structures in this mixture was studied using multidimensional mass spectrometry (MS). Mass spectrometry was interfaced with ultra-performance liquid chromatography (UPLC) and ion mobility (IM) separation. The mixture was separated by reversed-phase LC, oligomers of the star-branched polymer were separated according to …


Improved Thermal And Mechanical Properties And Increased Miscibility Of Polybenzoxazine In Blends With Functionalized Thermoplastics And Particles, Emily A. Brown Jan 2018

Improved Thermal And Mechanical Properties And Increased Miscibility Of Polybenzoxazine In Blends With Functionalized Thermoplastics And Particles, Emily A. Brown

WWU Graduate School Collection

The solubility, polymerization, and the macromolecular characterization of cured blends of BPA-based benzoxazine (BA-a) in end group tosylated poly(ethylene glycol) (mPEGOTs), polysulfone (PSUOTs), and poly(D,L-lactic acid) (PDLLAOTs) are studied and compared to their hydroxyl terminated analogues. The cure temperature for BA-a blends with tosylated polymers was reduced by ~60 °C compared to that of the pure BA-a. This confirms that the tosylated polymer is an accelerant for BA-a ring opening polymerization (ROP). There are two proposed mechanism for the production of free tosylate and cationic BA-a based initiators as a cure catalyst for BA-a ROP – where the former was …


Ultrasound-Assisted Surfactant/Ionic Liquid Aqueous Two-Phase System Extraction Prior To High Performance Liquid Chromatography For The Determination Of Tetracyclines In Milk And Honey Samples, Hayri̇ye Mi̇ne Antep, Taşkin Mumcu, Kami̇l Bostanci, Serap Seyhan Bozkurt, Melek Merdi̇van Jan 2017

Ultrasound-Assisted Surfactant/Ionic Liquid Aqueous Two-Phase System Extraction Prior To High Performance Liquid Chromatography For The Determination Of Tetracyclines In Milk And Honey Samples, Hayri̇ye Mi̇ne Antep, Taşkin Mumcu, Kami̇l Bostanci, Serap Seyhan Bozkurt, Melek Merdi̇van

Turkish Journal of Chemistry

In this work, an ultrasonic-assisted surfactant/ionic liquid aqueous two-phase system (ATPS) extraction method was developed to extract six tetracycline antibiotics from food samples before their chromatographic determination using high performance liquid chromatography. The ATPS was formed with 1-allyl-3-methyl-imidazolium bromide, Triton X-100, and dipotassium hydrogen phosphate. The parameters including type and amount of surfactant, ionic liquid and salt, pH of sample solution, and sonication time were optimized. Under the optimized conditions, linear calibration curves of the six tetracyclines were obtained in the range of 10--500 $\mu $g L$^{-1}$ with $>$ r$^{2} =$ 0.990 (n $=$ 9). The proposed green analytical …


Aqueous Foam Stabilized By Tricephalic Amphiphilic Surfactants, Seth A. Heerschap May 2015

Aqueous Foam Stabilized By Tricephalic Amphiphilic Surfactants, Seth A. Heerschap

Senior Honors Projects, 2010-2019

Aqueous foams can be described as a close packing of gas bubbles stabilized by surface active molecules. Their complex and diverse properties make them attractive for many chemical and physical applications where foaming, emulsifying or coating processes are needed. The recent synthesis of multi-cephalic and multi-tailed amphiphilic molecules have reportedly enhanced their antibacterial activity in connection with tail length and nature of the head group.

This report covers the foamability of two triple head, double tail cationic surfactants (M-1,14,14, M-P,14,14) and a triple head single tail cationic surfactant (M-1,1,14) and compares them with commercially available single headed, single tailed anionic …


Investigation Of Spontaneous Combustion Inhibition Of Coal Fires Utilizing Differential Scanning Calorimetry And Thermogravimetric Analysis, Christopher J. Raymond May 2015

Investigation Of Spontaneous Combustion Inhibition Of Coal Fires Utilizing Differential Scanning Calorimetry And Thermogravimetric Analysis, Christopher J. Raymond

Master of Science in Chemical Sciences Theses

Self-oxidation of coals can result in spontaneous combustion events at any time during mining, transporting, or processing, causing environmental, economical, and safety concerns. The total global primary coal production as of 2012 was 8.7 billion tons. Of that, 1.1 billion tons of coal was mined in the US, which accounts for 41% of the domestic electricity production. Spontaneous coal combustion, although dependent on coal rank, is a naturally occurring phenomenon that often causes damage to industrial and commercial facilities and freight, reduces the caloric value of coal, can release noxious gases and particulate matter, and increases CO2 pollution levels …


Cytotoxic Activity Of Triazole-Containing Alkyl Β-D-Glucopyranosides On A Human T-Cell Leukemia Cell Line, E. Davis Oldham, Larissa M. Nunes, Armando Varela-Ramirez, Stephen E. Rankin, Barbara L. Knutson, Renato J. Aguilera, Hans-Joachim Lehmler Jan 2015

Cytotoxic Activity Of Triazole-Containing Alkyl Β-D-Glucopyranosides On A Human T-Cell Leukemia Cell Line, E. Davis Oldham, Larissa M. Nunes, Armando Varela-Ramirez, Stephen E. Rankin, Barbara L. Knutson, Renato J. Aguilera, Hans-Joachim Lehmler

Chemistry (Legacy)

Simple glycoside surfactants represent a class of chemicals that are produced from renewable raw materials. They are considered to be environmentally safe and, therefore, are increasingly used as pharmaceuticals, detergents, and personal care products. Although they display low to moderate toxicity in cells in culture, the underlying mechanisms of surfactant-mediated cytotoxicity are poorly investigated.


Spectroscopic Studies On The Interaction Of Cetylpyridinium Bromide Monohydrate And Bromothymol Blue With Polymerized Silica, James Siegenthaler Jan 2015

Spectroscopic Studies On The Interaction Of Cetylpyridinium Bromide Monohydrate And Bromothymol Blue With Polymerized Silica, James Siegenthaler

All Master's Theses

The design and implementation of a controlled macromolecular chemical transport system could greatly advance switchable chemical reactions and be applicable for targeted drug delivery, intelligent inks, and nanotechnology. To better understand the mechanisms of function for a switchable macromolecular transport system, preliminary work has been completed that studies the transport of bromothymol blue (BB) facilitated by cetylpyridinium bromide monohydrate (CPBM) to a silica surface that has been modified with Poly(styrene-co-maleic anhydride), a pH switchable polymer. Ultraviolet spectroscopic trials were conducted measuring the absorbance of BB and CPBM at 3 pH levels and 3 different surface reactivity levels of …


Selective Co Methanation Over Nio--Al_2o_3--Zro_2 And Co_3o_4--Al_2o_3--Zro_2 Catalysts, Fi̇li̇z Derekaya, Derya Ermergen Jan 2015

Selective Co Methanation Over Nio--Al_2o_3--Zro_2 And Co_3o_4--Al_2o_3--Zro_2 Catalysts, Fi̇li̇z Derekaya, Derya Ermergen

Turkish Journal of Chemistry

NiO--Al_2O_3--ZrO_2 and Co_3O_4--Al_2O_3--ZrO_2 catalysts were prepared by three different co-precipitation methods, namely co-precipitation, surfactant-assisted co-precipitation, and surfactant-assisted co-precipitation with ultrasound mixing methods, and their activities were tested in selective CO methanation. Catalysts were characterized using N_2 physisorption, XRD, SEM, TEM, XPS, and TPR-H_2 techniques. CO methanation and selective CO methanation reactions were carried out. Catalysts prepared by surfactant assisted co-precipitation gave high surface area, uniform pore size distributions, and small pores. The NiO--Al_2O_3--ZrO_2 catalyst prepared by surfactant-assisted co-precipitation gave 50% CO conversion to CH_4 at 155 °C and all CO converted to CH_4 when T > 225 °C. For the selective …


Selective Co Methanation Over Ceo_2--Zro_2-Composed Nio And Co_3o_4 Catalysts, Fi̇li̇z Derekaya, Derya Ermergen Jan 2014

Selective Co Methanation Over Ceo_2--Zro_2-Composed Nio And Co_3o_4 Catalysts, Fi̇li̇z Derekaya, Derya Ermergen

Turkish Journal of Chemistry

CeO_2--ZrO_2-composed NiO and Co_3O_4 catalysts were prepared by 3 different methods. Both CO methanation and selective CO methanation were carried out. All catalysts were prepared by (1) co-precipitation, (2) surfactant-assisted co-precipitation, and (3) surfactant-assisted co-precipitation with ultrasound mixing methods. Catalysts were characterized by using N_2 physisorption, XRD, SEM, TEM, and TPR-H_2 techniques. The highest surface area value, uniform pore size distribution, and pores having small diameters were observed for the catalysts prepared by using the surfactant and ultrasound. The NiO/CeO_2/ZrO_2 prepared by the surfactant-assisted co-precipitation was the most active catalyst for CO methanation. It gave 50 % CO conversion to …


Phase Behavior And Rheology Of Latex, Thickener, Surfactant Mixtures And Liquid Crystal Based Compositions For Printing High-Efficiency Flexible Electronics, Franceska Anna Santos Dec 2013

Phase Behavior And Rheology Of Latex, Thickener, Surfactant Mixtures And Liquid Crystal Based Compositions For Printing High-Efficiency Flexible Electronics, Franceska Anna Santos

Master's Theses

This project consists of two parts. One area of focus in the first part is understanding the interactions between a non-ionic, block copolymer type dispersant and hydrophobically-modified, ethoxylated urethane (HEUR) associative thickeners in water. The dispersant was mixed at various concentrations (0-2% by weight) with HEUR thickeners at 1% by weight concentration in the aqueous medium. This study is an integral part of our attempts to determine mechanisms of viscosity drop when colorant dispersions are added to latex tint base formulations thickened with associative thickeners. One of the HEUR thickeners is a product that has been available for over three …


A Comparison Of Cationic Surfactant Immobilized Ion Exchange Membranes In Their Application For Use In Extraction Of 4-Nitophenol, Robert Derrek Brown Dec 2012

A Comparison Of Cationic Surfactant Immobilized Ion Exchange Membranes In Their Application For Use In Extraction Of 4-Nitophenol, Robert Derrek Brown

Dr Robert Brown

Solid Phase Extraction has replaced distillation and liquid-liquid extraction as the most widely used method for extraction from solution. Though traditional SPE has seen great success, its downfalls are that it requires meticulous preparation procedures requiring funtionalized silanes and silica or polymerization courses. An alternative is ion exchange membranes to which long carbon chain ionic surfactants have been attached. The S1000 membrane ion exchange capacity was measured to be approximately 110 micro-equil/disc while the P81 membrane was 150 micro-equil/disc. Octadecyltri-methylammonium surfactant was immobilized on the membrane surface, qualitated through the use of ATR-FTIR, and quantified through elemental analysis. Kinetic adsorption …


The Effects Of Color Concentrates On The Rheology Of Tint Bases, Doug James Herrick Dec 2012

The Effects Of Color Concentrates On The Rheology Of Tint Bases, Doug James Herrick

Master's Theses

ABSTRACT

THE EFFECTS OF COLOR CONCENTRATES ON THE RHEOLOGY OF TINT BASES

Douglas James Herrick

Waterborne coatings are formulated with a number of different ingredients; water, latex polymers, pigments, surfactants, dispersants, defoamers, biocides, coalescing aids, and rheology modifiers or thickeners. Rheology modifiers are necessary in order to improve the physical properties of the coating before, during, and after application to a substrate. There are two kinds of rheology modifiers used in waterborne coatings; associative thickeners and non-associative thickeners. Coatings formulated with associative thickeners are quite sensitive to coating variations; the slightest change in the formulation has profound effects on the …


Influence Of Reaction Parameters On The Synthesis Of Surfactant-Assisted Tin Oxide Nanoparticles, Muhammad Akhyar Farrukh, Prisca Tan, Rohana Adnan Jan 2012

Influence Of Reaction Parameters On The Synthesis Of Surfactant-Assisted Tin Oxide Nanoparticles, Muhammad Akhyar Farrukh, Prisca Tan, Rohana Adnan

Turkish Journal of Chemistry

Tin oxide nanoparticles were synthesized via hydrothermal method using a non-ionic surfactant, oleyl amine (OLM), in the presence of urea. The reactions were carried out at different calcination temperatures and varying concentrations of surfactant and urea. The effect of these reaction parameters on the particles' size, distribution, surface area, and the average pore diameter were investigated using X-ray diffraction analysis, transmission electron microscopy, scanning electron microscopy, energy dispersive X-ray analysis, thermogravimetric analysis, Brunauer-Emmett-Teller method, and Fourier transform infrared spectroscopy. Larger tin oxide nanoparticles were obtained with higher concentrations of urea. At the optimum experimental conditions, tin oxide nanoparticles with mean …


Determination Of Ni(Ii) With Picolinaldehyde-4-Phenyl-3-Thiosemicarbazone Used As A Chromogenic Reagent In A Nonionic Micellar System, Aamna Balouch, Muhammad Iqbal Bhanger, Farah Naz Talpur, Willie L. Hinze Jan 2011

Determination Of Ni(Ii) With Picolinaldehyde-4-Phenyl-3-Thiosemicarbazone Used As A Chromogenic Reagent In A Nonionic Micellar System, Aamna Balouch, Muhammad Iqbal Bhanger, Farah Naz Talpur, Willie L. Hinze

Turkish Journal of Chemistry

Spectrophotometric determination of Ni(II) was carried out using picolinaldehyde-4-phenyl-3-thiosemicarbazone (PAPT) as a complexing/chromogenic reagent. The possibility of using a micellar system was explored to enhance the degree of detection and allow a more sensitive spectrophotometric method for the determination of nickel ions. The anionic surfactant Triton X-100 greatly enhanced the molar absorptivity and limit of detection relative to that observed with bulk water or an organic solvent. The linear calibration graphs were obtained for 0.5-2.0 mg L^{-1} and 0.001-1.0 mg L^{-1} of Ni(II) in aqueous and surfactant media, respectively. Using this approach, the limit of detection for the PAPT-Ni(II) complex …


Enhanced [Ru(Bpy)_3]~(2+)-Mediated Oxidation Of Guanine Prompted By Dhp, Bao-Lian Zhang, Wei Hong, Bao-Yi Lu, Hong Li Nov 2009

Enhanced [Ru(Bpy)_3]~(2+)-Mediated Oxidation Of Guanine Prompted By Dhp, Bao-Lian Zhang, Wei Hong, Bao-Yi Lu, Hong Li

Journal of Electrochemistry

The effects of dihexadecyl phosphate(DHP) and multi-walled carbon nanotubes(MWNTs) on the oxidation of guanine mediated by[Ru(bpy)3]2+ on the ITO electrode have been investigated by cyclic voltammetry and differential pulse voltammetry.The results showed that [Ru(bpy)3]2+ can mediate the oxidation.In the range from 0.01 to 0.15 mmol·L-1,peak currents for guanine oxidation mediated by [Ru(bpy)3]2+ increased with the rise of DHP concentrations.On the contrary,cationic surfactant HTAC has the ability to weaken the mediated oxidation of guanine.In addition,the oxidative mechanism of guanine mediated by [Ru(bpy)3]2+ with the participation of DHP is discussed.


Studies Of Titanium Dioxide Nanoparticles And Surfactants Effects, Singly And In Combinations, On Luminescence Intensity Of Some Aromatic Compounds., Charles Anim Odame-Ankrah Aug 2009

Studies Of Titanium Dioxide Nanoparticles And Surfactants Effects, Singly And In Combinations, On Luminescence Intensity Of Some Aromatic Compounds., Charles Anim Odame-Ankrah

Electronic Theses and Dissertations

Luminescence techniques are sensitive, selective, and widely used in analysis. Luminescence intensity is attenuated by quenchers. This research has focused on the use of surfactants such as CTAB, SDS, and TX-100 singly or together with TiO2 nanoparticles to evaluate their individual and combined effects on some fluorescent aromatic compounds such as pyrene, fluoranthene, anthracene, phenanthrene, and carbazole. Rutile phase TiO2 was synthesized using the low temperature sol-gel method. Carbazole and phenanthrene were severely quenched by all surfactants singly or in combination with TiO2. Anthracene and fluoranthene showed some enhancement in their luminescence intensity. The most dramatic …


A Comparison Of Cationic Surfactant Immobilized Ion Exchange Membranes In Their Application For Use In Extraction Of 4-Nitophenol, Robert Derrek Brown Jan 2009

A Comparison Of Cationic Surfactant Immobilized Ion Exchange Membranes In Their Application For Use In Extraction Of 4-Nitophenol, Robert Derrek Brown

Mahurin Honors College Capstone Experience/Thesis Projects

Solid Phase Extraction has replaced distillation and liquid-liquid extraction as the most widely used method for extraction from solution. Though traditional SPE has seen great success, its downfalls are that it requires meticulous preparation procedures requiring funtionalized silanes and silica or polymerization courses. An alternative is ion exchange membranes to which long carbon chain ionic surfactants have been attached. The S1000 membrane ion exchange capacity was measured to be approximately 110 micro-equil/disc while the P81 membrane was 150 micro-equil/disc. Octadecyltri-methylammonium surfactant was immobilized on the membrane surface, qualitated through the use of ATR-FTIR, and quantified through elemental analysis. Kinetic adsorption …


Studies Of Surfactants Effect On Riboflavin Fluorescence And Its Determination In Commercial Food Products And Vitamin Tablets., William Emmanuel Ghann Dec 2008

Studies Of Surfactants Effect On Riboflavin Fluorescence And Its Determination In Commercial Food Products And Vitamin Tablets., William Emmanuel Ghann

Electronic Theses and Dissertations

A simple and economical fluorometer using blue LEDs excitation sources and simple PMT detection had been built, assembled, optimized, and employed for measurement of fluorescence from riboflavin (vitamin B2). Surfactants have been known to enhance the intensity of fluorescence of fluorescent compounds. Fluorescence analysis of riboflavin in the presence of various anionic, cationic, and nonionic surfactants was also conducted to determine if they could improve analysis. However, the surfactants employed did not seem to have any meaningful enhancement; in fact, some actually diminished the fluorescence intensity of riboflavin. The procedure was linear for riboflavin from 0.01 to 2.5 …


Numerical Aspects Of The Saft Equation Of State, Leah M. Octavio May 2006

Numerical Aspects Of The Saft Equation Of State, Leah M. Octavio

Senior Honors Projects

Equations of states are used to model fluid behavior. At a given temperature and pressure, for example, a mixture of water and alcohol might form a liquid and vapor phase, with the vapor phase being richer in alcohol and the liquid phase richer in water. In many industrial processes, such as distillation or extraction where mixtures of different compounds need to be separated, knowing how the fluid mixture will behave at various conditions helps make the operations more efficient and economical. While many equations of state exist, they differ in their accuracy in modeling systems and in their mathematical complexity. …