Effect of Sodium Halide on Micellar and Surface Properties of Cationic Silicone Surfactants

The effect of sodium halide on aggregation behavior of four cationic silicone surfactants, Si(3)mamCl, Si(4)mamCl, Si4PyCl, and Si(4)minCl, in solution was investigated using surface tension and conductivity measurements. The ability of sodium halide (NaCl, NaBr, and NaI) to reduce critical micelle concentration (CMC) values was in the order NaI > NaBr > NaCl. However, the(CMC)values of the cationic silicone surfactants, Si(4)mamCl, Si4PyCl and Si(4)minCl, in sodium halide solution are almost the same as those of the salt-free system. The values of Gm0andGads0 are negative, indicating that the micellization process and adsorption of the four cationic silicone surfactants at the air-solution interface are spontaneous.