Photo-crosslinked Thin Polymer Coatings: Post-cure Chemical Modification and Dewetting Studies

A bifunctional benzophenone chromophore, bis-BP, can photo-crosslink thin films of alkyne-terminated poly (styrene) polymer upon exposure to UV light. The crosslinked film is table towards water and DMSO, remaining physisorbed to a glass substrate after rinsing. The alkyne groups of the photo-crosslinked film can be used to bind molecules bearing azide groups via a Cu-catalyzed 1, 3-dipolar cycloaddition reaction. The method provides a facile approach to crosslink polymer chains with specific chemical functionalities that can be used for further chemical modification after curing. We characterize the photo-crosslinking, stability and surface reactivity with gel permeation chromatography (GPC), dewetting studies and fluorescence.