Studies on solvophobic interactions and micelle formation in non aqueous solvents

摘要

Micelle formation of various surfactants, such as sodium caprylate, sodium laurate, sodium palmitate and sodium stearate has been studied in organic solvents of various dielectric constants and intermolecular H-bonding capability, viz. molten acetamide, N-methyl acetamide (NMA) and N,N-dimethyl acetamide (DMA), at different temperatures by electrical conductivity and surface tension methods. Both methods show that micelles are formed in acetamide, NMA and DMA. Gibbs energy changes, enthalpies and entropies of micelle formation, respectively, have been determined by studying the variation of critical micelle concentration (c.m.c) with temperature. Micelle formation in these solvents has been explained on the basis of several factors such as dielectric constant of the medium, its intermolecular H-bonding capability including solvophobic interaction.