Analysis of adhesive and
mechanical properties of model
polymer surfaces can be achieved with an Atomic-Force
Microscope (AFM), in contact mode. The purpose of this study is to dissociate
the different contributions (chemical and mechanical)
included in an AFM force-distance
curve in order to establish relationships between interfacial tip-polymer
interactions and surface
viscoelastic properties of the polymer. Surface
Force measurements are, in a first step, done on
chemically modified silicon substrates (grafted with hydroxyl, amine, methyl and ester
functional groups). In order to investigate the effects of mechanical or
viscoelastic contributions, force
measurements on model polydimethylsiloxane (PDMS) networks, whose surfaces are
chemically modified with the same functional groups as for silicon substrates,
were achieved. New relationships are proposed between the local adhesion force and both the dissipation energy in the tip-polymer
contact and the surface properties of the materials (thermodynamic work of
adhesion). Moreover the dissipation function is related to Mc,
the mass between crosslinks of the polymer network.
More abstracts about the A nanoscale study of the adhesive contact