Molecular dynamics simulation of the interaction between palmitic acid and high pressure CO.

In this study, molecular dynamics simulation was used to explore the interaction characteristics of palmitic acid and CO, and the effects of temperature and pressure on the solubility of palmitic acid in CO were investigated. In the range of 293-353 K and 5-30 MPa, the snapshot of palmitic acid distribution in CO shows that the molecular chain of palmitic acid in high-density CO system is more straight and more dispersed than that in low-density CO system. The radial distribution function further clearly shows that the solubility of palmitic acid in CO decreases with the increase of temperature and increases with the increase of pressure, which is consistent with the fatty acid solubility data reported in the literature and the setting rules of supercritical CO extraction process conditions.

Molecular-level investigation of plasticization of polyethylene terephthalate (PET) in supercritical carbon dioxide via molecular dynamics simulation.

The current study aims to use the molecular dynamics (MD) simulation method to discuss the glass transition behaviour and fractional free volume () of the pure polyethylene terephthalate (PET) and the plasticized PET induced by supercritical carbon dioxide (SC-CO) sorption. The adsorption concentration reproduced through sorption relaxation cycles (SRC) was firstly estimated and in an order of magnitude with the known experimental results available in the reported literature. The induced by SC-CO in PET polymer changes regularly, which is proportional to the capacity of SC-CO adsorption with the changes in temperature and pressure.