Palm kernel oil mucilage as a source of bio-based cationic surfactants for effective control of water surface pollution: Synthesis, surface activity and petroleum capacities

Water contamination is a serious environmental issue with great negative impacts on the health of living organisms. Petroleum films from oil slicks represent one of the major water pollutants. The utilization of bio-based surfactants derived from natural sources/wastes can be an eco-friendly solution to address this problem. In such direction, a new series of palm kernel oil mucilage (PKOM)-based cationic surfactants (4a-e) has been synthesized through an efficient procedure and the structures were characterized spectroscopically. Firstly, the free fatty acids mixture was extracted from PKOM, reduced with LiAlH4 to the corresponding alcohols mixture and esterified with chloroacetic acid to afford fatty chlorides mixture. Parallelly, tertiary amine-tethering various aryl sulfonamides (3a-e) were prepared from the reaction of sulfonyl chlorides with a primary amine-tertiary amine hybrid compound. Finally, the target cationic surfactants were obtained via quaternization of the tertiary-N in 3a-e with the fatty chlorides. The surface activity and thermodynamic parameters of the synthesized bio-based surfactants have been determined. Moreover, the ability of these compounds to collect or disperse petroleum thin films in different water types was evaluated. Interestingly, almost all compounds exhibited strong abilities to collect or disperse these films from water even at high salinity percent (9 % NaCl).