Cationic gemini surfactants containing an O-substituted spacer and hydroxyethyl moiety in the polar heads: Self-assembly, biodegradability and aquatic toxicity

Abstract Micellization and some ecological properties of new cationic gemini surfactants with oxygen-substituted spacer and hydroxyethyl groups connected to the polar heads have been studied. The incorporation of a hydroxyethyl group in the polar head favors self-aggregation whereas the presence of the oxygen in the spacer increases critical micelle concentration. Surfactants investigated are not biodegradable due to their toxic effect on microorganisms responsible for biodegradation. Aquatic toxicity increases with the hydrophobic chain and decreases by increasing the hydrophilicity of spacer and polar heads. New gemini surfactants are less toxic to the aquatic environment than monomeric surfactants and non-oxygen-containing gemini surfactants.