Reverse thermal organogelation of poly(ethylene glycol)-polypeptide diblock copolymers in chloroform.

Most organogel formation has been observed at low temperatures and the gel melts as the temperature increases. As an opposite case to traditional organogels, we report a reverse thermal gelation of methoxy-aminopoly(ethylene glycol)-homopolypeptide block-copolymer chloroform solutions that undergo a sol-to-gel transition as the temperature increases. A series of methoxy-aminopoly(ethylene glycol)-homopolypeptide block copolymers showing reverse thermal gelation in chloroform was synthesized and we prove that the secondary structure of the polypeptide determines the morphology of the organogel.