Antimicrobial Surface Modification via Self-Assembled Nanopatterns of Block Copolymer Films

Fouling is the undesirable accumulation of a material on a variety of objects and has become a global problem. Surface topology is of great interest to develop bactericidal surfaces in place of traditional chemical-based approaches that are often toxic to humans and the environment. In this talk, we use nanopatterned surfaces fabricated by polystyrene-block-poly(methyl methacrylate) diblock copolymers as rational models. Oriented, self-assembled PS cylinders or lamellae were cross-linked by UV and the PMMA was removed by acetic acid. Our results with PS nanopillars (25 nm height & 60 nm spacing) showed bactericidal properties against Escherichia coli (E coli), while bacteria remain rod-shaped on “flat” PS or PMMA control surfaces. It was also found that PS nanowalls with height and spacing of about 20 nm show a similar bactericidal property, while the efficiency was much less when compared to the PS nanopillars. We will discuss the roles of geometric parameters of nanopatterned surfaces in bactericidal properties against the model bacterium.