Surface-initiated atom transfer radical polymerization grafting of poly(2,2,2-trifluoroethyl methacrylate) from flat silicon wafer surfaces

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 2 difunctional initiator, from 0.48 to 0.86 chains/nm(2). (c) 2005 Wiley Periodicals, Inc.