Sum frequency generation vibrational spectroscopy studies on water-soluble polymer interfaces

COLL 40

Takayuki Miyamae, t-miyamae@aist.go.jp, Nanotechnology Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Central 5, 1-1-1, Higashi, Tsukuba, Ibaraki, 305-8565, Japan
Water-soluble polymers have been attracting considerable attention for biomedical applications. Sum frequency generation (SFG) vibrational spectroscopy has been applied to investigate the several kinds of the water-soluble polymer interfaces. A series of amphiphilic block copolymers containing poly[oligo(ethylene glycol) methacrylate] segments and the corresponding poly[methyl ethers of oligo(ethylene glycol) methacrylate] block copolymer surfaces are investigated by using SFG in air. The terminal moiety on the oligo(ethylene glycol) side chain played an important role in determining the surface structure of the films. The hydrophilic block exposes the methyl termini to the surface and reduces the surface tension in air or vacuum. Poly(N-isopropylacrylamide) (pNIPAAm), which shows lower critical solution temperature (LCST) behavior in aqueous solutions, are also covered with the methyl groups of the side chain in air atmosphere. Molecular restructuring behavior of pNIPAAm grafted on the quartz will also be discussed.