Premium
Effect of hydrotropes on the aqueous solution behavior of surfactants
Author(s) -
Varade Dharmesh,
Bahadur Pratap
Publication year - 2004
Publication title -
journal of surfactants and detergents
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.349
H-Index - 48
eISSN - 1558-9293
pISSN - 1097-3958
DOI - 10.1007/s11743-004-0309-7
Subject(s) - chemistry , aqueous solution , cationic polymerization , pulmonary surfactant , sodium dodecyl sulfate , sulfonate , critical micelle concentration , inorganic chemistry , sodium , micelle , organic chemistry , biochemistry
Aqueous solutions of surfactants—cationic: tetradecyltrimethylammonium bromide (C 14 TABr); anionic: sodium dodecyl sulfate (SDS); and nonionic: polyoxyethylene t ‐octylphenol (trade name Triton X‐102, also called OPE‐8)— in the presence of three hydrotropes, viz. , sodium xylene sulfonate, sodium p ‐toluene sulfonate, and sodium chlorobenzene sulfonate, were examined by measuring surface tension, viscosity, and cloud points for the nonionic surfactant. The results show a marked decrease in the critical micelle concentration with increase in hydrotrope concentration for C 14 TABr, a marginal decrease for SDS, and very little change for OPE‐8 up to 0.1 M hydrotrope. The viscosity of cationic surfactant solutions showed a remarkable increase in the presence of trace amounts of hydrotropes (up to 15 mM). In contrast, the SDS solution showed only a slight increase in viscosity at high hydrotrope concentration (150 mM), and the viscosity of the OPE‐8 solution remained constant. The cloud point of OPE‐8 increased in the presence of hydrotropes, unlike its behavior with the simple salt NaCl. The strong dependence of the solution behavior of cationic surfactants on the presence of hydrotropes is discussed in terms of electrostatic interaction.