Tunable Organogelator from Alkyl-Polypeptide Diblock Prepared by Ring-Opening Polymerization

Three alkyl-polypeptide hybrid amphiphiles were synthesized by the ring-opening polymerization (ROP) of -(2-methoxyethoxy)esteryl-l-glutamate N-carboxyanhydride (l-EG(1)Glu NCA) using alkylamine, i.e. C6H13NH2, C14H29NH2, and C16H33NH2, as initiators. As-prepared alkyl-poly-l-EG(1)Glu hybrids were found to form clear organogels in several organic solvents at low concentration. FTIR and circular dichroism characterizations suggested that poly-l-EG(1)Glu formed a predominantly -sheet conformation, which accounted for the gelation. Transmission electron and atomic force microscopy characterizations revealed that these copolymers formed nanoribbon structures in THF.