Interaction of a spherical particle with linear chains

Linear flexible polymers both at low and high concentrations surrounding a single hard sphere are simulated using the cooperative motion algorithm on the face-centered cubic lattice. The excluded-volume condition between different monomers is taken into account and the size ratio q=R/R_g of the sphere radius and the mean radius of gyration of the chains is considered as a parameter. Structure of the system in the vicinity of the sphere is analyzed in comparison with the structure of the bulk solution for a wide range of q. The limiting case of the infinite sphere radius R→∞, i.e., the effect of the neutral wall on the chains, is also presented. The simulations indicate (1) a depletion layer in the neighborhood of the sphere, (2) an enhancement of the chain ends concentration at the particle surface, (3) an enhancement of the chain center-of-mass concentration at some distance from the surface for large q, (4) a penetration of the centers of mass into the sphere for small q, (5) an orientation ordering of the chains in the region of interest.