VIRIAL EXPANSION FOR A POLYMER WITH A REALISTIC PAIR-POTENTIAL INTERACTION

No modern theory of polymer excluded volume adequately describes the c rossover From poor solvent to good solvent conditions; a fundamental d ifficulty is a singularity in the binary cluster integral. Mayer expan sion techniques are applied to a model with a pair interaction between monomers to clarify the distinction between ''geometric'' and ''solve nt'' contributions to excluded volume. Detailed calculations are under taken for a hard-core potential and a mimic Lennard-Jones potential. T he significance of the singularity in the binary cluster integral for calculations in the crossover regime is discussed.