The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Satya P Moulik - One of the best experts on this subject based on the ideXlab platform.
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ternary mixtures of alkyltriphenylphosphonium bromides c12tpb c14tpb and c16tpb in aqueous medium their interfacial bulk and fluorescence quenching behaviour
Journal of Chemical Sciences, 2010Co-Authors: Gargi Basu Ray, Soumen Ghosh, Satya P MoulikAbstract:The self-aggregation behaviour of ternary mixtures of alkyl (C12-, C14- and C16-) triphenylphosphonium bromides was studied by Conductometry and tensiometry. The pure surfactants showed two Critical Micellar Concentrations (CMCs) by Conductometry, but their ternary mixtures produce single CMC both by Conductometry and tensiometry. The CMC values determined were found to be lower than that obtained from Clint equation suggesting synergistic interaction among the monomers within the micelles. Their bulk properties, like fraction of counterions bound to the micelles and free energy of micellization were evaluated. Interfacial parameters, like surface excess, minimum head group area of monomer and free energy of adsorption were also assessed. Interfacial adsorption was found to be more spontaneous than micellization. The head group area per monomer in ternary systems was larger than pure systems due to stronger electrostatic repulsion among the charged head groups. The values of the packing parameters supported the pure as well as ternary micelles to be spherical. The TPB surfactants efficiently quenched pyrene fluorescence; the performances of the homologues in this respect were assessed.
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the solution behavior of poly vinylpyrrolidone its clouding in salt solution solvation by water and isopropanol and interaction with sodium dodecyl sulfate
Journal of Physical Chemistry B, 2008Co-Authors: Abhijit Dan, Soumen Ghosh, Satya P MoulikAbstract:This article deals with the solution properties of poly(vinylpyrrolidone) (PVP) in salt and surfactant environment. The cloud point (CP) of PVP has been found to be induced by the salts NaCl, KCl, KBr, Na2SO4, MgSO4, and Na3PO4. On the basis of CP values for a salt at different [PVP], the energetics of the clouding process have been estimated. The effect of the surfactant, sodium dodecyl sulfate (SDS), on the salt-induced CP has also been studied, and reduction in CP at low [SDS] and increase in CP at high [SDS] have been observed. The water vapor adsorption of PVP has been determined by isopiestic method. The results display a BET Type III isotherm whose analysis has helped to obtain the monolayer capacity of PVP and formation of multilayer on it. The solvation of PVP in a solution of water and a water-isopropanol mixture has been determined by Conductometry from which contribution of the individual components were estimated. The interaction of PVP with SDS in solution led to formation of a complex entity, which has been studied also by Conductometry adopting a binding-equilibrium scheme. SDS has been found to undergo two types of binding as monomers in the pre- critical aggregation concentration (CAC) range and as small clusters in the post CAC region. The stoichiometries of binding and binding constant were evaluated.
Wangsong Wang - One of the best experts on this subject based on the ideXlab platform.
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investigation of pseudo polyanion formation between polyvinylpyrrolidone and sodium dodecanoate in aqueous solution by capillary electrophoresis Conductometry tensiometry and calcium stability
RSC Advances, 2017Co-Authors: Miaomiao Chen, Yun Fang, Wangsong WangAbstract:There is a lack of information about association between nonionic polymers and weak electrolyte type anionic surfactants, therefore the complexation between polyvinylpyrrolidone (PVP) and sodium dodecanoate (SD) is investigated by capillary electrophoresis for the first time, in assistance with Conductometry, tensiometry and calcium stability. The experimental results show that values of critical aggregation concentration (cac) and polymer saturation point (psp) of the system determined by several methods are consistent with each other. It is firstly found that the PVP–SD complex is actually PVP–SD pseudo-polyanions with different charge densities corresponding to different pH levels. It is also found that H-bonding and counterion bridging between PVP and bound SD micelles play important roles in the self-assembling of the PVP–SD pseudo-polyanions, and the pH-dependent capillary electrophoresis behavior of the pseudo-polyanions is ascribed to sodium bridging being replaced by H-bonding at lower pH.
Tiverios Vaimakis - One of the best experts on this subject based on the ideXlab platform.
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Estimation of AOT and SDS CMC in a methanol using Conductometry, viscometry and pyrene fluorescence spectroscopy methods
Chemical Physics Letters, 2012Co-Authors: Anastasios I. Mitsionis, Tiverios VaimakisAbstract:Critical micelle concentration (CMC) of two anionic surfactants in methanol was estimated using Conductometry, viscometry and pyrene fluorescence spectroscopy methods. The surfactants used, were sodium bis(2-ethylhexyl) sulfosuccinate (Aerosol-OT, AOT) and sodium dodecyl sulfate (SDS) dispersed in pure methanol. The CMC determination was evaluated in room temperature. The results have shown nearly similar concentrations.
Amalendu Pal - One of the best experts on this subject based on the ideXlab platform.
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interaction between amphiphilic ionic liquid 1 butyl 3 methylimidazolium octyl sulfate and anionic polymer of sodium polystyrene sulfonate in aqueous medium
Chemical Physics Letters, 2016Co-Authors: Z Barhoumi, M Saini, Noureddine Amdouni, Amalendu PalAbstract:Abstract The micellization of an aqueous solution of the surface active ionic liquid (SAIL), 1-butyl-3-methylimidazolium octylsufate (C4mim)(C8OSO3) and its interaction with an anionic polymer sodium polystyrene sulfonate, (NaPSS) were studied using conductimetry, tensiometry and fluorimetry. Surface tension profile shows a more dramatic increase in the value of surface tension of aqueous (C4mim)(C8OSO3) before the critical micelle concentration (cmc) of IL. The critical micelle concentration (cmc) value of this surfactant was found out from conductance measurements. The thermodynamic parameters, i.e., Gibb’s free energy, enthalpy, and entropy of micellization of the IL in aqueous solution have been calculated. Behavior of fluorescence probe confirms the binding interactions between SAIL and the polyelectrolyte.
Rahmat Sadeghi - One of the best experts on this subject based on the ideXlab platform.
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vapor pressure osmometry volumetry and Conductometry investigations on the interaction of sodium dodecyl sulfate with poly ethylene glycol and poly propylene glycol in aqueous solutions
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2013Co-Authors: Elham Bayat, Rahmat SadeghiAbstract:Abstract Micellar and thermodynamic properties of sodium dodecyl sulfate (SDS) in aqueous solutions of polyethylene glycol (PEG) (Mw = 400, 2000, 6000 and 10,000 g mol−1) and polypropylene glycol (PPG) (Mw = 400 g mol−1) were determined employing vapor pressure osmometry (VPO), volumetry, compressibility and Conductometry techniques at different temperatures. The binding of SDS in aqueous solution with PEG and PPG was investigated by comparison of the thermodynamic properties of aqueous solutions of SDS in the absence and presence of PEG and PPG. In aqueous solutions, SDS does not bind to PEG400 chains however it binds to PPG400, PEG2000, PEG6000 and PEG10000 chains. The plots of water activity, specific conductivity, sound velocity and isentropic compressibility against surfactant concentration for aqueous SDS + polymer (PPG400, PEG2000, PEG6000 and PEG10000) solutions show two break-points: critical aggregation concentration (CAC) and polymer saturation point (C2).