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CP: Chemische Physik
CP 25: Poster: Symposium: Benetzung und dünne Filme
CP 25.7: Poster
Montag, 22. März 1999, 18:00–20:00, R52/R72
Decay of surface corrugation gratings in polymer films near the glass transition — •Marc Hamdorf and Diethelm Johannsmann — Max-Planck-Institut für Polymerforschung, Ackermannweg 10, D-55128 Mainz
We report on surface-rheological experiments making use of the decay of imprinted surface corrugation gratings. The grating decay at temperatures higher than the glass transition temperature Tg is driven by surface tension. >From the balance between surface tension and viscous stress the near-surface complex shear modulus G(ω) for the first 100nm can be derived. For polystyrene surfaces we find shear moduli like the corresponding bulk values measured with a standard rheometer. Also we can meassure the near-surface glass transition temperature. Down to film thicknesses of about 30nm we find no deviation from the bulk calorimetric Tg.