Summary: Oligo(ethylene glycol) methacrylate (OEGMA) was grafted from silicon wafer surfaces by surface‐initiated atom transfer radical polymerization (ATRP) with CuIBr/2,2′‐bipyridine (bpy) as a catalyst and various water/alcohol mixtures as solvents. The ellipsometric thickness of the poly(OEGMA) layer on the surface increased linearly with monomer conversion in solution. High graft densities were achieved in alcohols. The graft density of poly(OEGMA) in methanol was found to be 0.26 chains · nm−2, which is 50% higher than that in water/methanol (30:70, v/v). The differences in graft density were correlated to the conformation of tethered poly(OEGMA) chains. Large poly(OEGMA) coils on the surface in the presence of water limited the access of initiation sites to the catalyst complex and monomer molecules.Development of poly(OEGMA) layer thickness on the silicon surface vs monomer conversion.imageDevelopment of poly(OEGMA) layer thickness on the silicon surface vs monomer conversion.

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Poly(2,2,2‐trifluoroethyl methacrylate) (PTFEMA), a partially fluorinated polymer, was directly grafted from silicon wafer surfaces by a surface‐initiated atom‐transfer radical polymerization (ATRP). The polymer layer thickness increased linearly with monomer conversion and molecular weight of free polymers in solution. The thickness was mainly determined by the experimental conditions such as activator/deactivator ratio, monomer/catalyst ratio, and monomer concentration. PTFEMA layers of more than 100‐nm thick were obtained. The grafted PTFEMA chains were “living” and allowed the extension of a second block of PMMA. X‐ray photoelectron spectroscopy study showed that the chemical compositions at the surfaces agreed well with their theoretical values. A novel surface‐attachable difunctional initiator was also synthesized and applied to the grafting of PTFEMA. The grafting density was doubled using this difunctional initiator, from 0.48 to 0.86 chains/nm2. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1252–1262, 2006

Acrylic polymers, including poly(methyl methacrylate), poly(2,2,2-trifluoroethyl methacrylate), poly( N,N'-dimethyaminoethyl methacrylate), and poly(2-hydroxyethyl methacrylate) were grafted from flat nickel and copper surfaces through surface-initiated atom transfer radical polymerization (ATRP). For the nickel system, there was a linear relationship between polymer layer thickness and monomer conversion or molecular weight of "free" polymers. The thickness of the polymer brush films was greater than 80 nm after 6 h of reaction time. The grafting density was estimated to be 0.40 chains/nm2. The "living" chain ends of grafted polymers were still active and initiated the growth of a second block of polymer. Block copolymer brushes with different block sequences were successfully prepared. The experimental surface chemical compositions as measured by X-ray photoelectron spectroscopy agreed very well with their theoretical values. Water contact angle measurements further confirmed the successful grafting of polymers from nickel and copper surfaces. The surface morphologies of all samples were studied by atomic force microscopy. This study provided a novel approach to prepare stable functional polymer coatings on reactive metal surfaces.

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