Sliding Grafted Polymer Layers

Shear-Induced Deformation and Desorption of Grafted Polymer Layers

We describe the behaviour of grafted polymer layers in strong solvent shear flows within a model where only a subset of chains are exposed to the flow (hence to the tension arising from hydrodynamic drag forces), leaving the remainder protected. We show that for quite small values of the shear rate, I, the system reaches a self-regulating state where the lowest possible fraction of grafted chai...

Patterned colloid assembly by grafted photochromic polymer layers.

Quartz surfaces and colloidal silica particles were derivatized with a poly(methyl methacrylate) copolymer containing spirobenzopyran (SP) photochromic molecules in the pendant groups at a concentration of 20 mol %. Two-photon near-IR excitation (approximately 780 nm) was then used to create chemically distinct patterns on the modified surfaces through a photochromic process of SP transformatio...

Sliding friction between an elastomer network and a grafted polymer layer: the role of cooperative effects

We study the friction between a flat solid surface where polymer chains have been end-grafted and a cross-linked elastomer at low sliding velocity. The contribution of isolated grafted chains’ penetration in the sliding elastomer has been early identified as a weakly velocity dependent pull-out force. Recent experiments have shown that the interactions between the grafted chains at high graftin...

Synthesis of high-density grafted polymer layers with thickness and grafting density gradients.

A novel approach was developed for the synthesis of tethered polymer layers with thickness and grafting density gradients. Poly(glycidyl methacrylate) (PGMA) was employed as a primary anchoring layer to attach the polymer chains to the surface of a silicon wafer. A linear temperature gradient heated stage was used for the generation of a gradual variation in the thickness of the anchoring PGMA ...

Extension and Compression of Grafted Polymer Layers in Strong Normal Flows