Monte Carlo Prediction of the Structure Factor of Polyethylene in Good and ϑ-Solvents

Using Monte Carlo techniques on a united atom model of polyethylene, we predict the structure factor of a single polymer chain g ( q ) at all length scales for ϑ and good solvent conditions. The solvent quality is included in the nonlocal monomer−monomer potential of mean force through an ad hoc parameter controlling the balance between repulsive and attractive contributions. Chains up to 4096 C−C bonds have been treated to get, in the “intermediate” regime of q, the well-established scaling law g ( q ) = Aq -1/ν where ν is the Flory exponent depending upon the quality of the solvent. For the q range above the scaling regime, the flexible rod model of Porod−Kratky is found to apply satisfactorily.