Development of Amphiphilic N-Isopropylacrylamide Oligomers and Polymers, and Their Composites with Metal Ions

Abstract

Amphiphilic N-isopropylacrylamide (NIPAAm) oligomers with dodecyl groups and carboxyl groups were prepared using RAFT polymerization. The aqueous solutions of the amphiphiles become clouded upon heating at pH 4. However, there is no thermosensitivity such as clouding at pH 8, and the formation of vesicle networks leads to a stable state in aqueous solution. In addition, nanowires, nanorods, and nanoparticles were developed using metal ion and/or metal complexes with these oligomers solutions. In particular, NIPAAm oligomers/Cu²⁺ ion displayed thermosensitivity with color change, indicating a change of coordination structure. The concept of hybrids of NIPAAm oligomer and metal ions allows us to design flexible and functional supramolecular systems in water.