Berlin 2001 – wissenschaftliches Programm

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CPP: Chemische Physik und Polymerphysik

CPP 1: Special Symposium: Molecular Dynamics in Confined Geometries

CPP 1.6: Hauptvortrag

Montag, 2. April 2001, 16:30–17:15, 3010

Properties of Glassy Thin Polymer Films — •Günter Reiter — ICSI, Mulhouse, France

I will present experimental results on the wetting properties and the apparent glass transition temperature of ultrathin polymer films on variously treated silicon substrates. The main focus will be on what are the consequences of film preparation and the resulting non-equilibrium conformations of the polymers on
a) measurements of the glass transition temperature in thin films
b) wettability of films much thinner than the unperturbed size of the polymers
c) measurements of the chain dimensions parallel to the surface and the observed annealing effects
d) rupture of polystyrene films below about 100 nm although the Hamaker constant has the wrong sign and films should be metastable
e) specific density of polymers in thin films
Results on polystyrene are compared with the behavior of polydimethylsiloxane films which are not undergoing a glass transition during film preparation. I also will discuss the consequences non-equilibrium conditions of polymers confined in thin films may have for the interpretation of published work on this subject.