Synthesis of block copolymers for surface functionalization with stimuli-responsive macromolecules

Using block copolymers with poly(n-butyl acrylate) (PBA) as anchor block being capable to tether the temperature-responsive block poly(N-isopropylacrylamide) (PNIPAAm) to the surface, polysulfone (PSf) films were functionalized applying an adsorption/surface entrapment process. Homo and block copolymer synthesis was investigated applying atom transfer radical polymerization (ATRP) using tris(2-(dimethylamino)ethyl)amine (Me₆TREN), CuCl and N,N-dimethylformamide (DMF). On basis of the determined critical micelle concentration of the block copolymers, surface functionalization of PSf was performed from an aqueous solution containing 25 vol% dimethylacetamide. These functionalized surfaces exhibit reversible temperature dependent properties due to the lower critical solution temperature (LCST) of PNIPAAm as can be proven by contact angle measurement. Furthermore, the beneficial effect of the PBA block with adjusted molecular weight on the stability of these coatings was proven. This surface functionalization method has various potential applications and the resulting surfaces are anticipated to exhibit actively triggerable ‘chaotic’ properties as basis of an efficient anti-biofouling strategy.