INVESTIGATION OF POLYMER BRUSHES AND ADSORBED LAYERS UNDER SHEAR

Neutron reflectometry was used to investigate the density profiles of polymer brushes and an adsorbed polymer layer under shear. The brushes consisted of end-functionalized deuterated polystyrene. The adsorbed polymer was a random copolymer of deuterated styrene and 4-vinylpyridi ne. The brush and the adsorbed layer were sheared by the flowing of so lvents over the polymer, with a maximum shear rate of 10(4) s(-1). Den sity profiles of the brush and the layer were determined before, durin g and after shear. The shear had no observable effect on the polymer p rofiles in any of the experiments. We discuss these results in the con text of other experiments and a recent theory.