Effect of end group-substrate interaction on aggregation structure of polystyrene ultrathin films

The aggregation structure of proton-, monocarboxyl-, and dicarboxyl terminated polystyrene (PS) ultrathin films spin-coated onto different substrate surfaces was investigated on the basis of atomic force microscopy (AFM). In the case of the monocarboxyl- and dicarboxyl-terminated PS ultrathin films spin-coated onto Si-wafer, the dewetting occurred after annealing above their bulk glass transition temperatures. In contrast, those (monocarboxyl and dicarboxyl-terminated PS ultrathin films spin-coated) onto aminosilane-treated Si-wafer did not dewet even after annealing above the bulk T_g, owing to the specific interaction between -COOH and -NH₂ groups of aminosilane onto the Si-wafer.