Block polystyrene-b-poly(acrylic acid) (PS-b-PAA) copolymers were obtained by means of atom transfer radical polymerization (ATRP), and then were covalently grafted to γ-(2,3-glycidoxypropyl)- trimethoxysilane (GPS) modified Si surfaces to obtain the solvent surfaces. GPC, FTIR, ¹H NMR and AFM were used to characterize the samples and surfaces. The sur-face responsive behaviors were investigated by water contact angle (CA) measurements. It shows that the wetting properties of the surfaces were dependent on the compositions of grafted copolymer and the proper-ties of the solvents. The surface modified with the compolymer, which has lower PS/PAA ratio, is more hy-drophilic under the same treatment. Hydrophilic surfaces were obtained after the treatments of ethanol and basic aqueous solution, while toluene and acidic aqueous solution treatments would result in the surface hy-drophobicity. Moreover, the switching behaviors of the surface were also proved to be very stable with the external acid-base stimuli.

Key words: atom transfer radical polymerization, block copolymer, smart surface, reversibility