The Role of Backbone Hydration of Poly(N-isopropyl acrylamide) Across the Volume Phase Transition Compared to its Monomer.

ABSTRACT: Thermo-responsive polymers undergo a reversible coil-to-globule transition in water after which the chains collapse and aggregate into bigger globules when passing to above its lower critical solution temperature (LCST). The hydrogen bonding with the amide groups in the side chains has to be contrasted with the hydration interaction of the hydrophobic main-chain hydrocarbons. In the present investigation we study molecular changes in the polymer poly(N-isopropyl acrylamide) (PNIPAM) and in its monomer N-isopropyl acrylamide (NIPAM) in solution across the LCST transition. Employing Fourier-transform infrared spectroscopy we probe changes in conformation and hydrogen bonding. We observe a nearly discontinuous shift of the peak frequencies and areas of vibrational bands across the LCST transi

SUBMITTER: Futscher MH 

PROVIDER: S-EPMC5717149 | biostudies-literature | 2017 Dec

REPOSITORIES: biostudies-literature