Biomedical subjects

Lionel Bureau

Publications and source records attributed to Lionel Bureau.

2 recordsLinked to original sources

PubMed2006

Frictional dissipation and interfacial glass transition of polymeric solids.

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.

Journal Article↗

PubMed2004

Sliding friction at a rubber/brush interface.

We study the friction of a poly(dimethylsiloxane) (PDMS) rubber network sliding, at low velocity, on a substrate on which PDMS chains are end-tethered. We thus clearly evidence the contribution to friction of the pullout mechanism of chain ends that penetrate into the network. This interfacial dissipative process is systematically investigated by probing the velocity dependence of the friction stress and its variations with the grafting density and molecular weight of the tethered chains. This allows us to confirm semiquantitatively the picture of arm retraction relaxation of the grafted chains proposed in models of slippage at a network/brush interface.

Journal Article↗