Chain stiffness and bond correlations in polymer brushes

Abstract

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