文摘
Silicones with enhanced protein resistance were prepared by introducing poly(ethylene oxide) (PEO) chains viasiloxane tethers (a-c) of varying lengths. Three unique ambifunctional molecules (a-c) having the general formula-(EtO)3Si(CH2)2-oligodimethylsiloxanen-block-poly(ethylene oxide)8-OCH3 (n = 0 (a), 4, (b), and 13 (c)) wereprepared via regioselective Rh-catalyzed hydrosilylation. Nine films were subsequently produced by the H3PO4-catalyzed sol-gel cross-linking of a-c each with ,-bis(Si-OH)polydimethylsiloxane (P, Mn = 3000 g/mol)in varying ratios (1:1, 1:2, and 2:3 molar ratio a, b, or c to P). Films prepared with a 2:3 molar ratio (a-c to P)contained the least amount of un-cross-linked materials, which may migrate to the film surface. For this set offilms, surface hydrophilicity and protein resistance increased with siloxane tether length (a-c). These resultsindicate that PEO was more effectively mobilized to the surface if incorporated into silicones via longer siloxanetethers.