“Grafting-from” Synthesis of Fluorinated Acrylamide Polymer Brushes: from Controlled Polymerization to Outstanding Antifouling Properties

Abstract

We report the synthesis of an antifouling polymer brush based on N-(2-fluoroethyl)acrylamide (FEAm) via the “grafting-from” method using surface-initiated atom transfer radical polymerization. We compare its antifouling properties with those of its well-known 2-hydroxyethyl-based counterparts: poly[N-(2-hydroxyethyl)acrylamide] and poly(2-hydroxyethyl acrylate). Judicious selection of surface-anchored initiating group enables the attainment of controlled polymerization kinetics and the precise tuning of brush thickness. Optimal conditions were assessed on substrates bearing two types of initiator, namely 2-bromoisobutyrate and 2-chloropropionate. Surface characterization through X-ray photoelectron and Fourier-transform infrared spectroscopies confirmed that the targeted chemical structures of the polymers were attained without the formation of side products. In addition, pFEAm brush exhibited remarkable hydrophilicity even though it does not present the functional groups typical for hydrophilic antifouling brushes, and its resistance to fouling from undiluted blood plasma was on par with other commonly employed coatings (a reduction of 95% with respect to bare SiO₂). Considering these results and its demonstrated properties as tracer in ¹⁹F MRI diagnostics, pFEAm emerges as a compelling coating material for devices requiring antifouling properties in ¹⁹F MRI.