The relaxation dynamics of a rubbed polystyrene (PS) surface have been characterized using infrared-visible sum frequency generation spectroscopy (SFG). The SFG results were compared with previous relaxation of retardation measurements, and the results show that the rubbed PS surface has the same T(g) as the bulk where T(g) is defined as tau(T(g))=5 s, however, the surface has a lower activation energy (DeltaE) and a larger stretching exponent (beta(KWW)) than bulk PS. This indicates that the surface region relaxes more quickly than the bulk. The thickness of this region of lower DeltaE and larger beta(KWW) is estimated to be roughly 12 nm.
Physical Review E
Required Publisher's Statement
Copyright 2003 American Physical Society. The original published version of this article may be found at http://dx.doi.org/10.1103/PhysRevE.67.021802.
Schwab, Alexander D. and Dhinojwala, Ali, "Relaxation of a Rubbed Polystyrene Surface" (2003). College of Polymer Science and Polymer Engineering. 20.