• Ng, Gervase
• Wu, Zilong
• Zhang, Tong
• Dang, Anh Phong
• Yao, Yin
• Postma, Almar
• Prescott, Stuart
• Nelson, Andrew
• Boyer, Cyrille
• Hawker, Craig

Abstract

An oxygen-tolerant SI-PhotoRAFT technique has been developed for the efficient synthesis of surface-tethered polymer brushes under low-energy near-infrared (NIR) light. This technique takes advantage of the unique properties of NIR light, in particular enhanced penetration, to effectively prepare polymeric coatings even through opaque barriers. The NIR-mediated SI-PhotoRAFT polymerization exhibits polymerization kinetics characteristic of reversible deactivation radical polymerization (RDRP), a linear increase in brush height with irradiation time, and sequential chain extension to form block copolymer brushes. Moreover, the incorporation of a photoresponsive monomer, 7-[4-(trifluoromethyl)coumarin] acrylamide (TCAm), within the poly(dimethylacrylamide) brushes enables orthogonal control over polymerization and crosslinking processes using two different wavelengths (NIR and UV light). When exposed to a UV source (λ = 365 nm, 18.2 mW/cm2), the TCAm undergoes dimerization triggering crosslinking of the grafted brush ‘arms’. Furthermore, by utilizing the enhanced penetration of NIR light, a polymeric coating was prepared on the inner walls of opaque tube. Finally, this process is successfully applied to the synthesis of antifouling surfaces on poly(dimethyl siloxane) (PDMS) coated silicon wafers leading to inhibition of biofouling.

Topics

• impedance spectroscopy
• surface
• Oxygen
• Silicon
• copolymer
• block copolymer