CHAIN STIFFNESS AND BOND CORRELATIONS IN POLYMER BRUSHES

We have incorporated chain stiffness and correlations between neighbor ing bonds into a self-consistent field (SCF) lattice model for end-att ached polymer layers (commonly known as ''brushes''). An increase in t he chain stiffness leads to an increasing brush height. This increase is directly related to the change of the length of a Kuhn segment in t he polymer chain. Introducing correlations between neighboring bonds g ives a higher density of the brush, corresponding to a decrease of the brush height. For not too stiff chains these two effects virtually co mpensate each other. Hence, the volume fraction profile of ''real'' gr afted chains is nearly identical to that of a polymer brush consisting of freely jointed chains.