MOLECULAR-DYNAMICS OF LINEAR AND BRANCHED ALKANES - SIMULATIONS AND NUCLEAR-MAGNETIC-RESONANCE RESULTS

We have extended two previously introduced models of n-alkanes to nume rically investigate the liquid-state dynamics of branched alkanes. We compare our results with new experimental measurements of diffusion an d C-13-NMR T-1 relaxation. Significant systematic and quantitative agr eement is found between simulated and experimental values. We demonstr ate the role of branching in controlling the temperature dependence of diffusion and point out the effect of global single-chain relaxation processes on the local intramolecular dynamics probed by the C-13-NMR experiment. (C) 1996 American Institute of Physics.