Free energy calculations of small molecules in dense amorphous polymers. Effect on the initial guess configuration in molecular dynamics studies

Vegt van der, Nico F.A. and Briels, Wim J. and Wessling, Matthias and Strathmann, Heiner (1996) Free energy calculations of small molecules in dense amorphous polymers. Effect on the initial guess configuration in molecular dynamics studies. Journal of Chemical Physics, 1996 (105). pp. 8849-8857. ISSN 0021-9606

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Abstract:	The excess free energy of small molecules in the amorphous polymers poly(ethylene) and poly(dimethylsiloxane) was calculated, using the test-particle-insertion method. The method was applied to polymer configurations obtained from molecular dynamics simulations with differently prepared initial guess configurations. It was found that the calculated solubility coefficients strongly depend on the quality of the initial guess configuration. Slow compression of dilute systems, during which process only the repulsive parts of the nonbonded Lennard-Jones potentials are taken into account, yields polymer melts which are better relaxed, and which offer lower solubilities for guest molecules compared with polymer melts generated at the experimental density or prepared by compressing boxes with soft-core nonbonded potentials. For the last two methods initial stresses relax by straining the internal modes (bond angles, torsion angles) of the chains
Item Type:	Article
Copyright:	© 1996 American Institute of Physics.
Faculty:	Science and Technology (TNW)
Research Group:	Computational Biophysics (CBP) Membrane Science and Technology (MST)
Link to this item:	http://purl.utwente.nl/publications/11464
Official URL:	http://dx.doi.org/10.1063/1.472614
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