Theoretical study of polymer brushes by a new numerical mean field theory

We present a new numerical self-consistent mean field approach in order to investigate poly-disperse polymer brushes dissolved in solvent. In this new method, the polymer segments are contained in a tube filled with solvent, which allow the realization of several configuration of the chain. The tube conformation is developed on a lattice using Kuhn segment, such that the volume of the polymer chain is the same with the one measured experimentally. In order to deal with the depletion layer observed in the volume fraction profile in previous theoretical investigations and obtain more brush-like conformations at high enough concentrations, we introduce a new parameter (disturbed walk parameter), which characterizes the degree of the deviation from the random walk growth. The results show a better description of the brush at high concentrations. Close to the surface, disappearance of the depletion layer was observed. Also we have accomplished the correct description of the brush extension. (c) 2006 Elsevier Ltd. All rights reserved.