Monte Carlo simulations of conformations of short chains near a cylindrical rod

Off-lattice Monte Carlo simulations are employed to study the behavior of short chain molecules near a long cylindrical rod. The molecules are modeled by freely jointed hard sphere chains. The emphasis is placed on the chain and bead distributions as well as the location dependence of the chain conformation and anisotropy. The simulation results show that at a given low chain concentration, the surface curvature of the rod gives rise to a slight increase in the bead concentration within the depletion layer. As the separation distance from the rod decreases, the chains first contract slightly and exhibit weak anisotropy in favor of an orientation parallel to the rod axis. With further increase in the closeness, to the contrary, the chains elongate and adopt a conformation that tends to wrap around the rod. This intriguing behavior is attributed primarily to the effect of the cylindrical surface. (C) 2003 American Institute of Physics.