Synthesis of Some New Quaternary Ammonium Compounds Evaluation of their Surface properties and Solubilization Activity

Four cationic surfactants were prepared by condensing fatty acid methyl diethanolamine derivatives (C6, CI0, CI2, CI8) with stoichiometric amounts of trimethyl chlorosilane. The surface properties and parameters were investigated to find the relationship between the structure of the hydrophobic portion of such compounds and their efficiency toward solubilization. The properties studied included surface excess concentration (Γmax), critical micelle concentration (cmc). free energy of micellization (ΔGοmic) and adsorption (ΔGοads) in addition to the surface tension (γcmc) at cmc and effectiveness (Πcmc). The values of Γmax, ΔGο mic and ΔGοads were found to increase with increasing number of chain length. while cmc and minimum surface area occupied by one molecule (Amin) were decreased. Solubilization effect of these surfactants on paraffin oil as a non polar solubilizate and biodegradability were studied