Relation between volume expansion and hydrogen bond networks for CO2-alcohol mixtures at 40 °C

Tsutomu Aida; Takafumi Aizawa; Mitsuhiro Kanakubo; Hiroshi Nanjo

doi:10.1021/jp1017339

Relation between volume expansion and hydrogen bond networks for CO2-alcohol mixtures at 40 °C

J Phys Chem B. 2010 Nov 4;114(43):13628-36. doi: 10.1021/jp1017339.

Authors

Tsutomu Aida¹, Takafumi Aizawa, Mitsuhiro Kanakubo, Hiroshi Nanjo

Affiliation

¹ National Institute of Advanced Industrial Science and Technology, Research Center for Compact Chemical Process, 4-2-1 Nigatake, Miyagino-ku, Sendai 983-8551, Japan.

PMID: 20936838
DOI: 10.1021/jp1017339

Abstract

We experimentally determined the density and mole fraction of CO(2) (x(CO(2))) for CO(2)-alcohol (methanol, ethanol, propanol, butanol, isopropyl alcohol, and tert-butyl alcohol) mixtures and performed molecular dynamics (MD) simulations to study the mechanisms of volume expansion at 40 °C. The volume as calculated by vapor-liquid equilibrium (VLE) data increased with decreasing alkyl chain length, although there was no effect of branched alkyl groups. Analysis of the hydrogen bond network showed that the average number of hydrogen bonds per alcohol molecule decreased with increasing branched methyl groups. At pure alcohol condition, large size hydrogen bond networks were made. With further addition of CO(2) molecules, it became difficult to contain the large hydrogen bond networks. Furthermore, the hydrogen bond networks changed to a cyclic pentamer or tetramer, and volume expansion occurred.