Monte Carlo simulations of colloidal pair potential induced by telechelic polymers: Statistics of loops and bridges

A Monte Carlo study of the statistics of loop and bridge formation between colloidal particles, and in particular micelles, by telechelic polymers is presented. The experimental fact that the hydrophobic outer blocks of a triblock copolymer tend to stick into micelles in aqueous solution is mimicked by counting only polymer chains with both ends on the surface of the micelles. The long inner hydrophilic block is generated by a random walk procedure. It is excluded from the volume of the micelles, and it can form either a loop, with both stickers on the same micelle, or a bridge, with the stickers on two different micelles. In this paper, the pair potential is determined between two micelles as a function of distance and chain-to-micelle size ratio, for ideal and self-avoiding chains. In the latter case, the effect of many chains has also been explored.