MOLECULAR-DYNAMICS SIMULATIONS OF ATHERMAL POLYMER BLENDS - FINITE SYSTEM SIZE CONSIDERATIONS

Molecular dynamics simulations of binary, athermal blends of chains consisting of 50 tangent sites were carried out over a range of compositions at liquidlike packing fractions. The sites interact with repulsive Lennard-Jones potentials and have effective hard sphere diameters of approximately 1.0 and 1.2 for the two site types. The intrachain and interchain correlation functions were found and, except for the single component systems, the interchain correlations were seen to de strongly dependent on system size. Trivial, long range correlations due to the finite system size can be approximated from simple physical arguments, and the coarse, interchain, radial distribution functions can be ''corrected'' for these effects. The resulting correlation functions are seen to behave at large separation as would be expected of interchain radial distribution functions in an infinite sized system, permitting meaningful comparisons with the predictions of liquid state theory. (C) 1995 American Institute of Physics.