Macromolecules, Vol.47, No.7, 2411-2419, 2014
Polymer Brushes Exhibiting Versatile Supramolecular Interactions Grown by Nitroxide-Mediated Polymerization and Structured via Microcontact Chemistry
Functionalization of metal, glass, and semiconductor substrates with polymers and nanoparticles is a key challenge for surface-based material science. Such substrates have the potential to find widespread application in optical and electronic devices, microarrays, and materials for information storage. We report sitespecific immobilization of nitroxide-mediated polymerization initiators via microcontact chemistry employing thiol ene click chemistry on glass-supported alkene-terminated self-assembled monolayers. The polymer initiator covered substrates are used for preparation of poly(styrene) and poly(acrylate) brushes with defined and tunable brush thicknesses. Brush thickness dependent site-specific protein adsorption of streptavidin and concanavalin A on structured polystyrene brushes is reported. Poly(styrene) brushes with a thickness of 40 nm or larger showed protein repellence whereas brushes below 15 nm thickness reveal protein adhesive properties. We also disclose the site selective host guest assisted immobilization of beta-cyclodextrin-coated silica nanoparticles a liposomes modified with amphiphilic beta-cyclodextrin onto adamantane-functionalized poly(acrylate) immobilization of these supramolecular colloids via the multivalent hydrophobic inclusion complex of adamantane can be readily verified by fluorescence microscopy imaging, atomic force microscopy, microbalance with dissipation monitoring.