A5084904411- Surfactants and Colloidal Systems
- Electrochemical Analysis and Applications
- Analytical Chemistry and Chromatography
- Lipid Membrane Structure and Behavior
- Photochemistry and Electron Transfer Studies
- Spectroscopy and Quantum Chemical Studies
- Analytical Chemistry and Sensors
- Advanced Polymer Synthesis and Characterization
- Molecular Junctions and Nanostructures
- Photoreceptor and optogenetics research
- Environmental Chemistry and Analysis
- Electrostatics and Colloid Interactions
- Dendrimers and Hyperbranched Polymers
- Laser Design and Applications
- Chemical and Physical Properties in Aqueous Solutions
- Luminescence and Fluorescent Materials
- Microbial Inactivation Methods
- Porphyrin and Phthalocyanine Chemistry
- Laser-Matter Interactions and Applications
- Protein Interaction Studies and Fluorescence Analysis
- Inorganic and Organometallic Chemistry
- Semiconductor materials and interfaces
- DNA and Nucleic Acid Chemistry
- Silicon and Solar Cell Technologies
- Semiconductor materials and devices
Aixtron (Germany)
2024
Fritz Haber Institute of the Max Planck Society
1996-2007
University of Salford
1998-2005
Rutherford Appleton Laboratory
2000-2004
University of Cyprus
2004
Unilever (United Kingdom)
1999-2000
University of Victoria
1998-1999
Freie Universität Berlin
1992
Johns Hopkins Medicine
1986
Johns Hopkins University
1986
It has been established that sodium dodecyl sulfate (SDS) binds to the micelles and monomers of block copolymer F127. SDS monomeric unassociated F127 in form polymer/bound micellar complexes. first forming mixed micelles, which dissociate into smaller aggregates then single monomers. A third interaction SDS, involves promotion at concentrations up 3 °C below critical temperature pure F127, was identified is investigated present work. The formation such SDS-induced monitored using...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTReliability of the Experimental Methods To Determine Equilibrium Constants for Surfactant/Cyclodextrin Inclusion ComplexesH. Mwakibete, R. Cristantino, D. M. Bloor, E. Wyn-Jones, and J. F. HolzwarthCite this: Langmuir 1995, 11, 1, 57–60Publication Date (Print):January 1995Publication History Published online1 May 2002Published inissue 1 January 1995https://pubs.acs.org/doi/10.1021/la00001a013https://doi.org/10.1021/la00001a013research-articleACS...
We applied isothermal titration calorimetry (ITC) and surface tension (ST) electromotive force (emf) measurements using a coated wire sodium dodecyl sulfate membrane-selective electrode to measure the mixed micellar composition of various mixtures triblock copolymer EO97PO69EO97, nonionic surfactant code-named Pluronic F127, with (SDS). In region where micelles are formed, interaction between two surfactants showed synergistic behavior parameters β, which characterize nonideal in micelles,...
The binding of SDS to pluronic F127 was studied using a surfactant selective electrode via electromotive force, isothermal titration calorimetry, and light scattering. At concentration 0.5% w/v the block copolymer exists as an equilibrium mixture micelles monomers at 35 °C. When is gradually added this solution, takes place even lowest measured (1 × 10-5 mol dm-3). Initially F127/SDS mixed are formed size these remains constant until ∼5 dm-3 has been reached. total 5 there ∼6 in aggregate...
The interaction between the cationic surfactant tetradecyltrimethylammonium bromide (TTAB) and Pluronic triblock copolymer F127 was investigated. is a nonionic with structural formula EO97PO69EO97, where EO represents ethylene oxide block PO propylene block. A combination of experiments involving TTAB selective electrode (electromotive force), isothermal titration calorimetry (ITC), differential scanning (DSC), light scattering have shown that binds to both monomeric micellar F127. forms...
Isothermal titration calorimetry (ITC) and differential scanning (DSC) measurements were carried out on various binary mixtures of the nonionic surfactant hexaethylene glycol mono-n-dodecyl ether (C12EO6) triblock copolymer "Pluronic" F127 chemical composition EO97PO69EO97, which is a polymeric (EO represents poly(ethylene oxide) blocks PO polypropylene oxide blocks). In all cases mixed micellar aggregates formed critical concentrations (cmc's) containing different mole fractions surfactants...
The complexation behavior of 1-naphthyl-1-ethanol (1-NpOH) and 2-naphthyl-1-ethanol (2-NpOH) with β-cyclodextrin (β-CD) was studied by employing several spectroscopic techniques. In the case 1-NpOH, only a complex 1:1 stoichiometry is formed β-CD, which has an equilibrium constant that smaller than observed for between β-CD 2-NpOH. Excimer emission in presence solutions containing high 2-NpOH concentrations. This excimer ascribed to 2:2 β-CD/2-NpOH stoichiometry. addition, 1H NMR data...
EMF measurements on binary mixtures of the cationic surfactants tetradecyltrimethylammonium bromide and tetradecylpyridinium a range nonionic polymers have been carried out. The existence polymer/surfactant complexes was found for those whose microstructures contain side groups with hydrophobic character. Isothermal titration microcalorimetry were also taken to obtain more information about polymer/cationic surfactant complexes. An examination dependence monomer concentration following...
Electromotive force and isothermal titration microcalorimetry measurements have been carried out to study the interactions of sodium dodecyl sulfate (SDS) with polyethyleneimines (PEI's) some ethoxylated PEI's at different pH's. In all cases polymers show a remarkable affinity toward SDS. The SDS concentration onset binding decreases decreasing pH. At low pH's phase separation similar that observed for strong polyelectrolyte/oppositely charged surfactant systems occurs presumably as...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTEquilibrium and Kinetic Studies Associated with the Binding of Sodium Dodecyl Sulfate to Polymers Poly(propylene oxide) Ethyl(hydroxyethyl)celluloseD. M. Bloor, W. Z. Wan-Yunus, A. Wan-Badhi, Y. Li, J. F. Holzwarth, E. Wyn-JonesCite this: Langmuir 1995, 11, 9, 3395–3400Publication Date (Print):September 1, 1995Publication History Published online1 May 2002Published inissue 1 September...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTNanosecond temperature-jump technique with an iodine laserJ. F. Holzwarth, A. Schmidt, H. Wolff, and R. VolkCite this: J. Phys. Chem. 1977, 81, 24, 2300–2301Publication Date (Print):December 1, 1977Publication History Published online1 May 2002Published inissue 1 December 1977https://pubs.acs.org/doi/10.1021/j100539a021https://doi.org/10.1021/j100539a021research-articleACS PublicationsRequest reuse permissionsArticle...
The interactions of sodium dodecyl sulfate (SDS) with the triblock copolymer L64 (EO13−PO30−EO13) and hexaethylene glycol mono-n-dodecyl ether (C12EO6) were studied using electromotive force, isothermal titration microcalorimetry, differential scanning micocalorimetry, surface tension measurements. In certain regions binding, mixed micelles are formed, here we could evaluate an interaction parameter regular solution theory. both SDS C12EO6 exhibit synergy. When is present in its...
The continuous-flow method with integrating observation (CFMIO) has been used to investigate irreversible electron-transfer (ET) reactions between negatively charged, substitution-inert transition metal complexes. Special attention paid in order distinguish the different contributions energy of activation such as size reactants, long-range charge interactions, influence free (difference redox potential) and composition (electrolytic content) solutions. We selected ET reaction Fe(CN)6Hx–4x...
Abstract The continuous flow method, with observation along the concentration profile in direction of flow, has previously been used to measure rate constants very rapid irreversible reactions up 10 7 1 mol −1 sec . Improvements cell design and monitoring facilities now permit study greater than 9 eight electron transfer transition metal complexes are reported this article.
The interaction between the dendrimers poly(1,4-diaminobutane) DABn (n = 8, 16, 32, 64) and poly(pyrrolidone-1,4-diaminobutane) DABnPy 32) with surfactants sodium dodecyl sulfate (SDS), tetradecyltrimethylammonium bromide (TTAB), hexaethyleneglycol monododecyl ether (C12EO6) have been studied using electromotive force (EMF) measurements involving a surfactant-selective electrode also isothermal titration microcalorimetry (ITC). EMF data shows apparent binding of SDS to all at concentrations...
The binding of both an anionic surfactant, sodium dodecyl sulfate (SDS), and a cationic tetradecyltrimethylammonium bromide (TTAB), to various water soluble copolymers containing equal amounts the monomers methyl vinyl imidazole (MVI) pyrrolidone (VP) third monomer, acrylic acid(AA), have been studied using surfactant selective electrodes isothermal titration microcalorimetry (ITC). change in behavior surfactants has investigated as charge content acid monomer systematically altered. data...
A poly(ethylene oxide) derivative of polyethyleneimine behaves like a strong polyelectrolyte at pH = 2.5 and neutral polymer 10. Both the charged uncharged versions this bind strongly to surfactant sodium dodecyl sulfate (SDS) with no phase separation taking place. Binding isotherms were measured using electrode, these data complemented isothermal titration calorimetry (ITC) measurements. Small-angle neutron scattering measurements also carried out some specific concentrations in binding...
Abstract We report a systematic investigation of the influence anionic micelles (SDS) on kinetics diffusion controlled outer sphere electron transfer reactions between transition metal complexes. — The interact with reactants through electrostatic repulsion (e. g. IrCl 6 2 ) or attraction which can cause ion association Os(dipy) as well hydrophobic forces Fe(phen) (CN) 0 ). rate constants k ET these range in order 10 M −1 s aqueous solution and are decreased by more than four orders...
The optimization of neutral polymer/anionic surfactant mixtures is a critical process in the development such systems for many various applications. In this report, we describe how systematic isothermal titration microcalorimetry experiments may be designed way that both adsorption and desorption processes sodium dodecyl sulfate with two polymers, PAPR* (a copolymer N-(vinylacryloyl)pyrrolidine containing covalently bonded 4-vinylpyridine dicyanomethylide chromophore) PVP...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPolymer/Surfactant Interactions. The Use of Isothermal Titration Calorimetry and emf Measurements in the Sodium Dodecyl Sulfate/Poly(N-vinylpyrrolidone) SystemD. M. Bloor, J. F. Holzwarth, E. Wyn-JonesCite this: Langmuir 1995, 11, 6, 2312–2313Publication Date (Print):June 1, 1995Publication History Published online1 May 2002Published inissue 1 June 1995https://doi.org/10.1021/la00006a074Request reuse permissionsArticle...
The polymer−surfactant complex formed between sodium dodecyl sulfate (SDS) and poly(vinylpyrrolidone) (PVP) contains SDS micelles bound to the polymer chain. When a PVP sample of MW 360 000 is saturated with micelles, beadlike structure wrapped around 25 micelles. was systematically removed from chain by addition nonionic surfactant hexaethylene glycol mono-n-dodecyl ether, C12EO6, this process monitored using isothermal titration calorimetry (ITC). Electromotive force, emf, measurements...
Interactions in aqueous solutions of different generations poly(amidoamine) (PAMAM) dendrimers containing amine, hydroxyl, or δ-glucolactone functional groups at the periphery with anionic surfactant sodium dodecyl sulfate (SDS) were investigated. We used a SDS-specific electrode (EMF) for SDS monomer concentration monitoring, isothermal titration calorimetry (ITC) binding information, and small angle neutron scattering (SANS) structural studies. ITC experiments monitoring interaction...