Hybrid Molecular Brushes with Chitosan Backbone: Facile Synthesis and Surface Grafting

We developed a facile route toward amphiphilic hybrid molecular brushes (HMB) with chitosan backbone and concurrently grafted chains of poly­(acrylamide) and polystyrene. The grafting occurs through amino groups of chitosan; no extra modification of chitosan is required. The kinetic and molecular weight characteristics of the primary molecular brush CHI-<i>graft</i>-PAAm are studied. The second step is grafting of PS by emulsion polymerization. The resulting HMB CHI-<i>graft</i>-PAAm-<i>graft</i>-PS form very stable emulsions. We attached the HMB on solid substrates using chitosan backbone by the “grafting to” approach. Thin films of the immobilized HMB of 3–11 nm thickness completely cover the surface. Being amphiphilic by nature, the immobilized HMB reveal the ability to adapt to the medium, which results in shifting of the hydrophobic/hydrophilic balance over a wide range