Interfacial activities and aggregation behaviors of N-acyl amino acid surfactants derived from vegetable oils

Abstract

The development of amino acid surfactants which are considered to be biodegradable and less toxic than traditional surfactants has been a subject of growing interests among chemists for the past 20 years. Within this category, N-acyl amino acid surfactants are popular due to their excellent interfacial properties and antimicrobial activities. In the present work, six new N-acyl amino acid surfactants were synthesized using vegetable oils (castor oil and cottonseed oil) and amino acids (glycine, alanine, and serine). Surface active properties of these surfactants were investigated. With the amide bonds acting as hydrogen bond donors and acceptors, globular and tubular vesicles were observed in the aqueous solutions of some prepared surfactants. The results indicated that hydroxyl groups on the hydrophobic tails for castor oil derivatives were associated with spherical vesicles formation, whereas serine residues bearing hydroxyl groups may be associated with the tubular vesicles.