A facile approach to modify poly(dimethylsiloxane) surfaces via visible light-induced grafting polymerization

Tailoring the surface properties of poly(dimethylsiloxane) (PDMS) is essential for the advancement of its applications. However, the modification process is usually complicated and limited due to the chemical inertness of the surfaces of PDMS. Here, we report for the first time, a facile and versatile method for the functional surface modification of PDMS via visible light-induced grafting polymerization at room temperature. This modification is readily achieved in two steps: (1) covalently integrating alkyl bromine into the PDMS networks using a simple mixing procedure and (2) visible light-induced surface grafting polymerization using Mn₂(CO)₁₀. We have demonstrated that the PDMS surface can be functionalized with a wide variety of polymers via covalent grafting, such as poly(trifluoroethyl methacrylate) (PTFEMA), poly(N-isopropylacrylamide) (PNIPAAm), poly(acrylic acid) (PAA) and poly(vinyl acetate) (PVAc). As an example, after the grafted PVAc was transformed into its hydrophilic analogue poly(vinyl alcohol) (PVA), anti-biofouling functionalization of PDMS was obtained. The anti-biofouling properties of the functionalized PDMS were demonstrated using cell adhesion and bacterial adhesion tests. Moreover, the grafting kinetics of PVAc showed that this process was fast and efficient.