Effects of solvent on polymer chain dimensions: a Born–Green–Yvon integral equation study

The equilibrium properties of a tangent-hard-sphere polymer chain (with site diameter σ) in a hard-sphere monomer solvent (with monomer diameter D=σ) are studied using the Born–Green–Yvon integral equation in conjunction with a two-site solvation potential. The solvation potential is constructed using low-density results for a hard-sphere trimer in a hard sphere solvent. The BGY equation has been solved for polymers of lengths up to 200 for a range of solvent densities. The theory accurately describes the compression of the average polymer dimensions with increasing solvent density. Scaling exponents relating the polymer dimensions to chain length and solvent density are also obtained.