Surface functionalization by smart binary polymer brushes to tune physico-chemical characteristics at biointerfaces

Abstract

Polymer brushes consist of an assembly of polymer chains that are attached by one end to the surface with sufficient grafting density. Binary brushes constituted from two incompatible polymers can be used in the form of ultrathin polymeric layers as a versatile tool for surface engineering to tune physicochemical surface characteristics as wettability, surface charge, chemical composition or morphology, and furthermore to create responsive surface properties. It is also possible to fix surface structures obtained in this way by (photo)crosslinking of the layers. Mixed brushes of oppositely charged polyelectrolytes are representing a special case of responding surfaces, which are sensitive to changes of the pH in aqueous environment. It is shown that structural changes occur in the plateau region of the adsorption isotherm of a model protein and that changes of the pH also cause changes in the structure of the adsorbed protein layer.