Ashwani Kumar Sood

Mixed Micellization Behavior of 12-2-12 Gemini Surfactant with Some Alkyltrimetyl Ammonium Bromide Surfactants

Mixed micellization behavior of dimeric cationic surfactant ethanediyl-1,2-bis (dimethyldodecylammonium bromide) (12-2-12) with a series of monomeric cationic surfactants dodecyltrimethyl ammonium bromide (DTAB), tetradecyltrimethyl ammonium bromide (TTAB), and cetyltrimethyl ammonium bromide (CTAB) has been studied in aqueous and aqueous polyvinylpyrrolidone (PVP) solutions at 298.15, 308.15, and 318.15 K, respectively, using conductometric method. Various thermodynamic parameters like mixed micelle concentration (Cm), micelle mole fraction (X1), interaction parameter (β), and free energy of mixing (ΔGex) of the mixed systems have been determined and analyzed using Rubinghs regular solution theory. The results indicate that in aqueous solutions the binary mixtures of 12-2-12 with DTAB/TTAB behave nonideally with mutual synergism whereas that with CTAB shows almost ideal behavior at 298.15 K. At 318.15 K, all these binary mixtures exhibit antagonistic behavior. The effect of variation in chain length of alkyltrimethyl ammonium bromide surfactants on the interactions with 12-2-12 have also been evaluated and discussed.

Study of Micellization Behavior of Some Alkyldimethylbenzyl Ammonium Chloride Surfactants in the Presence of Polymers

The micellization behavior of homologous series of cationic surfactants tetradecyl- (C14BCl), hexadecyl- (C16BCl) and stearyldimethyl-benzyl ammonium chloride (C18BCl) in water and in aqueous solutions of polymers such as polyvinyl pyrrolidone (PVP) and polyethylene glycols (PEG-20 and PEG-06) has been studied at 298.15 K using the conductometric method. The same method has also been used to study the mixed systems, that is, C16-C14BCl, C18-C16BCl, and C18-C14BCl over the whole mole fraction range of the higher chain length surfactant at 298.15, 308.15, and 318.15 K in water and in presence of 0.5 and 1.0% PVP by volume at 298.15 K. From these measurements various micellar parameters like critical aggregation concentration (CAC), polymer saturation point (PSP), degree of ionization (ψ), and standard free energy of transfer ( ) have been calculated. The CAC and values were found to decrease with increase in polymer concentration whereas PSP values were found to remain constant except in the case of C14BCl where PSP values were found to increase with polymer concentration. The regular solution approach has been applied to determine the mixed micelle mole fraction (X) and the interaction parameter (β). These parameters have also been discussed in terms of micelle-polymer interactions. The combination C16-C14BCl shows synergism at all the studied temperatures in aqueous solution whereas remaining combinations show antagonism (except for C18-C16BCl at 318.15 K). In presence of PVP, the binary mixtures show antagonistic behavior which increases with increase in PVP concentration.

Influence of organic solvents and temperature on the micellization of conventional and gemini surfactants: a conductometric study

ABSTRACT The micellar behaviour of similar hydrophobic chain length conventional (cetyltrimethyl ammonium bromide, CTAB; cetyl pyridinium chloride, CPC; cetyldimethylbenzyl ammonium chloride, C16BCl) and gemini surfactant (16-2-16) in water and polar non-aqueous solvents has been investigated in the temperature range 288.15–318.15 K with the help of conductivity measurements. The method proposed by Carpena et al. has been used to analyse the conductivity–concentration to determine the micellization parameters using critical micelle concentration (CMC) and degree of counter-ion dissociation (α) of the micelle. It shows much better performance than the conventional methods and the effect of experimental errors on the evaluation of the micellization parameters has been shown to be minimal by using this procedure. It was observed that the micellization tendency of the surfactant decreases in the presence of solvents. Thermodynamic parameters were also evaluated from the temperature dependence of the CMC values.

Mixed Micellization Behavior of Gemini and Conventional Surfactants: Influence of Spacer Length and Temperature

Mixed micellar behavior of gemini surfactant butanediyl-1,4-bis(dimethyldodecylammonium bromide) (12-4-12) with conventional surfactant tetradecyl trimethylammonium bromide (TTAB) has been studied in aqueous and in aqueous polyvinyl pyrrolidone (PVP) solutions at various temperatures (288.15 K, 298.15 K, 308.15 K, and 318.15 K) using conductometric method. The behavior of the mixed system has been analyzed in light of Rubinghs regular solution theory. The study indicates that the above system behaves nonideally with mutual antagonism which increases with temperature. The mixed micelle mole fraction of 12-4-12 has also been determined and is found to be almost same with its ideal state value at all the studied temperatures indicating that mixed micelles are equally occupied by both the surfactants in the whole mole fraction range. In the presence of PVP, the critical aggregation concentration and critical micellar concentration values were found to decrease with increase in mole fraction of 12-4-12 whereas these values increase with PVP concentration as well as temperature. Various thermodynamic parameters associated with transfer of surfactant monomers from the medium consisting of polymer-free mixed micelles to polymer-bound mixed micelles like , ,and at various temperatures have been evaluated and discussed.

Evaluation of micellar properties of sodium dodecylbenzene sulphonate in the presence of some salts

The influence of some salts (NaCl, KCl,

Effect of Head Groups, Temperature, and Polymer Concentration on Surfactant—Polymer Interactions

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Mixed Micellization Behavior of m-2-m Gemini Surfactants with Some Conventional Surfactants at Different Temperatures

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