Frictional dissipation and interfacial glass transition of polymeric solids

Phys Rev Lett. 2006 Dec 1;97(22):225501. doi: 10.1103/PhysRevLett.97.225501. Epub 2006 Nov 27.


We present single contact friction experiments between a glassy polymer and smooth silica substrates grafted with alkylsilane layers of different coverage densities and morphologies. This allows us to adjust the polymer-substrate interaction strength. We find that, when going from weak to strong interaction, the response of the interfacial junction where shear localizes evolves from that of a highly viscous threshold fluid to that of a plastically deformed glassy solid. This we analyze as resulting from an interaction-induced "interfacial glass transition" helped by pressure.