Surface and thermodynamic studies of N-alkkyl N-trimethylsilane ammonium chloride surfactants

N-Dodecyl N-trimethylsilane ammonium chloride, N-tetradecyl-N-trimethylsilane ammonium chloride, N-hexadecyl-N-trimethylsilane ammonium chloride, and N-octadecyl-N-trimethylsilane ammonium chloride were prepared. Surface properties, particularly critical micelle concentration (CMC), effectiveness, maximum surface excess, and minimal surface area, were determined at different concentrations at 20, 35, 50, and 65°C, respectively. From electrical conductivity data, degrees of dissociation and dissociation constants at various concentrations were determined. Free energies, enthalpies, and entropies of micellization and adsorption of the surfactants in aqueous solution were studied.