Synthesis and frictional properties of poly(2,3- dihydroxypropylmehtacrylate) brush prepared by surface-initiated atom transfer radical polymerization

The hydrophobic polymer brush was prepared by surface-initiated atom transfer radical polymerization of (2,2-dimethyl-1,3-dioxolan-4-yl)methyl methacrylate (1) on the initiator-immobilized silicon wafer using copper / sparteine complexes. The contact angle measurements, XPS, and FTIR studies revealed that the amphiphilic poly(2,3-dihyroxypropyl methacrylate) (2) brush was obtained, successively, by acidic hydrolysis of the poly(1) brush. Frictional properties of the poly(1) and (2) brushes were characterized by sliding a stainless or a glass ball probe on the polymer brush surfaces in air and water. Frictional coefficient of poly(2) brush was significantly lowered in water compared with that of poly(1) brush, while poly(2) brush showed larger frictional coefficient than poly(1) brush surface in air.