Polyampholytic Poly(AEMA-co-SPMA) Thin Films and Their Potential for Antifouling Applications

Polyampholytic poly(2-aminoethyl methacrylate-co-sulfopropyl methacrylate) (p(AEMA-co-SPMA)) thin films were prepared by self-initiated photopolymerization and photografting (SIPGP) and are demonstrated to be a potential alternative to films prepared from zwitterionic poly(sulfobetaine methacrylate) (pSBMA) for antifouling applications. SIPGP allows polymerization from aqueous solutions containing only monomers, implying that p(AEMA-co-SPMA) thin films can be prepared simply and inexpensively without the risk of introducing potentially toxic substances necessary in many controlled polymerization reactions. For the polymers, wettabilities were studied by contact angle goniometry, the compositions of the films were determined by infrared and X-ray photoelectron spectroscopies, and streaming current measurements were used to assess their net charge. The antibiofouling properties were compared via adsorption of fibrinogen and bovine serum albumin, settlement of algal zoospores, and the growth of sporelings of the marine alga Ulva lactuca. The fouling of the p(AEMA-co-SPMA) copolymer was in several respects similar to that of the zwitterionic pSBMA and suggests that it is potentially suitable for applications under high-salinity conditions, such as marine or physiological environments.