Antimicrobial activity of polyestyrene particles coated by photo-crooslinked block copolymers containing a biocidal polymethacrylate block

A commercially available poly(ethylene-co-butylene) copolymer, end-capped by a short polyisoprene block and a hydroxyl group (PI-b-PEB-OH), has been derivatized into a macroinitiator for atom transfer radical polymerization (ATRP) by esterification of the hydroxyl end-group by an activated bromide-containing acyl bromide. Two types of triblock copolymers, Pl-b-PEB-b-poly(dimethylaminoethyl methacrylate) (PDMAEMA) and Pl-b-PEB-b-poly[2-(tert-butylamino)ethyl methacrylate] (PTBAEMA), have been synthesized and used to coat polystyrene particles. These coatings have been permanently immobilized by UV cross-linking of the isoprene units. They exhibit a biocidal activity against Gram-negative bacteria either intrinsically in case of the PTBAEMA block or upon quaternization of the PDMAEMA block by octyl bromide. The antimicrobial activity is directly related to the concentration of coated PS particles in the medium.