title: Nonequilibrium polymer chains induced by conformational transitions in densely interfacial layers.
abstract: Nonequilibrium poly(N-isopropylacrylamide) (PNIPAM) chains are generated by temperature-induced conformational transitions in the densely interfacial PNIPAM layer at high adsorbed amounts in aqueous solution. The interleaving chains relax in a spatially heterogeneous space of adsorbed layer which is filled with the domains via the hydrogen bonding and hydrophobic interactions. The relaxation dynamics of interleaving chains is changed from the weekly stretched exponential behaviour at the lower adsorbed amount to the strongly stretched exponential behaviour at the higher adsorbed amount. The kinetic constraints for the relaxation dynamics depend on the segment density of the adsorbed layer which is controlled by the temperature. The stretched exponential relaxation is related to an ensemble of relaxations confined in the domains with different physical origins for the heterogeneous dynamics. The range of energy barriers for the relaxation is estimated from the stretched exponent based on the random first order transition theory.
authors.affiliation: Cooperative Research Centre for Polymers, Melbourne, Australia.
authors.forename: Peng-Wei
authors.initials: PW
authors.lastname: Zhu
mesh_terms: D000178:Acrylamides / Q000737:chemistry*; D000180:Acrylic Resins; D000327:Adsorption; D057446:Hydrodynamics; D007700:Kinetics; D008968:Molecular Conformation; D011108:Polymers / Q000737:chemistry*; D012996:Solutions; D013696:Temperature; D014867:Water / Q000737:chemistry
chemical_list: D000178:Acrylamides; D000180:Acrylic Resins; D011108:Polymers; D012996:Solutions; D014867:Water; C052970:poly-N-isopropylacrylamide