Covalently tethered comb‐like polymer brushes on hydrogen‐terminated Si (100) surface via consecutive aqueous atom transfer radical polymerization of methacrylates

The hydrogen‐terminated Si (100) (SiH surface) was functionalized by coupling with 4‐vinylbenzyl chloride (VBC) to form a SiVBC surface, which serves as macroinitiators for the surface‐initiated aqueous atom transfer radical polymerization (ATRP) of 2‐hydroxyethyl methacrylate (HEMA) and poly(ethylene glycol)methacrylate (PEGMA) to prepare SiVBC g PHEMA and SiVBC g PPEGMA substrates, respectively. The ellipsometric results revealed that the surface‐initiated ATRP of both PHEMA and PPEGMA brushes proceeded in a controlled fashion. By adjusting the monomer concentration, an eccentric polymer thickness dependence on the initial monomer concentration [ M ] 0 was observed for both HEMA and PEGMA, i.e., in the dilute regime, the thickness of the polymer film increases with the increase in [ M ] 0 ; however, beyond critical [ M ] 0 , the thickness deceases gradually with the further increase. Such an eccentricity was tentatively correlated to the counteractive combination of the increase in [ M ] 0 and decrease in the apparent polymerization rate constant. Both SiVBC g PHEMA and SiVBC g PPEGMA substrates were esterified for the subsequent surface‐initiated ATRP, resulting in corresponding comb‐like brushes. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2590–2599, 2006