Relaxation dynamics of rubbed polystyrene thin films. Agra, D. M. G.; Schwab, A. D.; Kim, J.-H.; Kumar, S.; Dhinojwala, A.. Department of Physics and Liquid Crystal Institute, Kent State University, Kent, OH, USA. Europhys. Lett. (2000), 51(6), 655-660. CODEN: EULEEJ ISSN: 0295-5075. Journal written in English. CAN 133:350952 AN 2000:685714 CAPLUS

Optical retardation measurements were used to probe the chain relaxation dynamics in rubbed polystyrene films of varying thicknesses on glass substrates. A model based on Kohlrausch-Williams-Watts relaxation was developed and used to det. the glass transition temp. (Tg) of the films. Results showed redns. of 15-20 K in Tg for thin films of thicknesses comparable to the radius of gyration as well as for cast films rubbed with different strengths. These results provide evidence of a faster relaxation dynamics relative to the polymer-substrate interface for thinner films and enhanced chain mobility at the polymer-air interface.