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Glass transitions of freely suspended polymer films

Pierre-Gilles de Gennes
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Abstract

We present a modified version of our "sliding model", where chain arcs, between two contacts at the surface, may move if all the barriers along the arc are weaker than a certain threshold.An important advance of the revised model is that the high limiting chain lengths N* observed in the experiments are naturally accoundted for. In this model, a film of thickness h, smaller than the coil size, can show either a "sandwich" structure with two mobile sublayers (at low temperatures T T(h). But the accident occurring at T=T(h), does not necessarily coincide with the apparent glass transition, determined by the intersection of two tangents in a plot of thickness versus temperature.

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Pierre-Gilles de Gennes. 2000-09-12. Glass transitions of freely suspended polymer films. https://arxiv.org/abs/cond-mat/0009176

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