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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 21: Poster: Confinement of Polymers in Nanoscopic Layers - How Much do Properties Change?

CPP 21.4: Poster

Dienstag, 15. März 2011, 18:00–20:00, P2

Calorimetric Glass Transition of Thin Poly(Bisphenol A Carbonate) Films — •Huajie Yin and Andreas Schönhals — BAM Federal Institute for Materials Research and Testing, Unter den Eichen 87, 12205 Berlin, Germany

The differential alternating current chip calorimeter with the sensitivity of a few tens of pJ/K was applied to study the glass transition of thin poly(bisphenol A carbonate) films with thickness ranging from 35 nm to 230 nm. The temperature dependent measurement (393.15-463.15 K) of complex heat capacity of nanometer-thin films was carried out in the frequency range typically from 1 Hz to 1000 Hz. Amplitude and phase angle of the complex differential voltage as a function of the temperature, respectively, were attained in the measurement, which can be used to determine the calorimetric glass transition temperature. No thickness dependency of calorimetric glass transition temperature was observed within an uncertainty of +/-3 K at every setting frequency. The frequency dependence of calorimetric glass transition temperatures was further analyzed by the fitting of Vogel-Fulcher-Tammann (VFT) equation. It is shown that there is no deviation from the common VFT behavior.