(303b) Measurement of Viscoelastic Properties of Supported Thin Polymer Films

For nearly two decades, research has been devoted to understanding the impact of nanoscale confinement and interfaces on the glass transition temperature (T_g) and mobility of thin polymer films.  Prior work in supported thin polymer films has utilized spectroscopic methods to measure T_g and mobility, while wrinkling methods have been applied to measure the instantaneous elastic modulus.  Here we present a non-contact method to measure the viscoelastic properties of supported thin polymer films.  The approach is based on the blow-off method originally developed by Derjaguin [1].  The method entails flowing gas under laminar flow conditions through a narrow channel in order to generate a well-define shear stress on a properly placed sample.  Our design is modernized in numerous ways, including, the ability to simultaneously control the gas and substrate temperature.  This new feature will allow for the measurement of temperature-dependent viscoelastic properties.  

[1] B.V. Derjaguin, V.V. Karasev, V.M. Starov, E.N. Khromova, Research into the Boundary Viscosity of Volatile Liquids by the Blow-off Method, J. Coll. Inter. Sci., 67 465 (1978)