Photocatalytic Antibacterial Capabilities of TiO2-Biocidal Polymer Nanocomposites Synthesized by a Surface-Initiated Photopolymerization

Novel biocidal polymer-functionalized TiO2 nanoparticles were prepared by surface-initiated photopolymerization using titania as an initiator. Vinyl monomer mixtures of nontoxic secondary amine-containing biocide] 2-(tert-butylamino)ethyl methacrylate and antifouling ethylene glycol dimethacrylate were used for the antimicrobial polymer shell. It was shown that the synthesized TiO2/poly[2-(tert-butylamino)ethyl methacrylateco-ethylene glycol dimethacrylate] core/shell nanoparticles had enhanced photocatalytic antibacterial properties compared to the pristine TiO2 nanoparticles due to the combined antibacterial activities of light-driven anti-infective TiO2 core and biocidal polymer shell. In the dark condition, the TiO2/biocidal polymer nanoparticles exhibited high antimicrobial efficiency (95.7%) against gram-positive S. aureus. Furthermore, during UV irradiation, the TiO2/biocidal polymer showed improved inhibition of bacterial growth against gram-negative E. coli and gram-positive S. aureus in comparison to the pristine TiO2 nanoparticles.