SEMIFLEXIBLE POLYMER BRUSHES - A SCALING THEORY

We present a simple scaling theory to describe the conformational prop erties of semiflexible polymers grafted on a flat surface. For orienta tion-dependent interactions between polymer segments, we analyzed the physical properties of a polymer brush from the collapsed to strongly stretched regimes. Our analysis predicts first-order isotropic-nematic phase transitions between isotropically and nematically collapsed bru shes, and between stretched and nematically collapsed brushes. It is a lso found that the orientational interactions would raise the effectiv e a temperature as compared with the isotropic counterparts. (C) 1998 American Institute of Physics. [S0021-9606(98)50349-4].