Monte Carlo simulations of equilibrium solubilities and structure of water in n -alkanes and polyethylene

Johansson, E; Bolton, K; Theodorou, DN; Ahlstrom, P

dc.contributor.author	Johansson, E	en
dc.contributor.author	Bolton, K	en
dc.contributor.author	Theodorou, DN	en
dc.contributor.author	Ahlstrom, P	en
dc.date.accessioned	2014-03-01T01:26:42Z
dc.date.available	2014-03-01T01:26:42Z
dc.date.issued	2007	en
dc.identifier.issn	0021-9606	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/18181
dc.subject.classification	Physics, Atomic, Molecular & Chemical	en
dc.subject.other	Hexane	en
dc.subject.other	Monte Carlo methods	en
dc.subject.other	Paraffins	en
dc.subject.other	Phase equilibria	en
dc.subject.other	Polyethylenes	en
dc.subject.other	Thermal effects	en
dc.subject.other	Water	en
dc.subject.other	Binary systems	en
dc.subject.other	Intermolecular Forces	en
dc.subject.other	Osmotic Gibbs	en
dc.subject.other	Solubility	en
dc.title	Monte Carlo simulations of equilibrium solubilities and structure of water in n -alkanes and polyethylene	en
heal.type	journalArticle	en
heal.identifier.primary	10.1063/1.2745296	en
heal.identifier.secondary	http://dx.doi.org/10.1063/1.2745296	en
heal.identifier.secondary	224902	en
heal.language	English	en
heal.publicationDate	2007	en
heal.abstract	Gibbs ensemble Monte Carlo methods based on a force field that combines the simple point charge [Berendsen , in Intermolecular Forces, edited by Pullman (Reidel, Dordrecht, 1981), p. 331] and transferable potentials for phase equilibria [Martin and Siepmann, J. Phys. Chem. B 102, 2659 (1998)] models were used to study the equilibrium properties of binary systems consisting of water and n-alkanes with chain lengths from hexane to hexadecane. In addition, systems where extended linear alkane chains (up to 300 carbon units long) were used to represent amorphous polyethylene were simulated in the presence of water using a connectivity altering osmotic Gibbs ensemble. In these simulations the equilibrium between a liquid water phase and a polymer phase into which water was inserted was studied. The predicted solubilities, which were determined between 350 and 550 K, are in good agreement with experiment, where experimental results are available, and the density of water molecules in the hydrocarbons is approximately 63% as high as in saturated water vapor under the same conditions. At the lower temperatures most of the water exists as monomers; increasing the temperature leads to an increase in the density of water in the alkane phase and hence in the fraction of molecules that participate in clusters. Dimers are the most prevalent clusters in all hydrocarbons and at all temperatures studied, and the fraction of clusters of given size decrease with increasing cluster size. A large fraction of trimers, tetramers, and pentamers, which are the cluster sizes for which topologies have been studied, are cyclic at low temperatures, but at higher temperatures linear structures predominate. The same properties are observed for pure water vapor clusters in equilibrium with the liquid phase, showing that the cluster topologies are not significantly affected by the surrounding hydrocarbon. (c) 2007 American Institute of Physics.	en
heal.publisher	AMER INST PHYSICS	en
heal.journalName	Journal of Chemical Physics	en
dc.identifier.doi	10.1063/1.2745296	en
dc.identifier.isi	ISI:000247247400043	en
dc.identifier.volume	126	en
dc.identifier.issue	22	en