title: Experimental evidence for interplay of dynamic heterogeneity and finite-size effect in glassy polymers.
abstract: Despite two decades of extensive research, direct experimental evidence of a dynamical length scale determining the glass transition of confined polymers has yet to emerge. Using a recently established experimental technique of interface micro-rheology we provide evidence of finite-size effect truncating the growth of a quantity proportional to a dynamical length scale in confined glassy polymers, on cooling towards the glass transition temperature. We show how the interplay of variation of polymer film thickness and this temperature-dependent growing dynamical length scale determines the glass transition temperature, which in our case of 2-3 nm thick films, is reduced significantly as compared to their bulk values.
authors.affiliation: Department of Physics, Indian Institute of Science, 560012, Bangalore, India.
authors.forename: A K
authors.initials: AK
authors.lastname: Kandar
authors.forename: J K
authors.initials: JK
authors.lastname: Basu