Microcosmic understanding on thickening capability of copolymers in supercritical carbon dioxide: the key role of π–π stacking

Abstract

Thickening capability evaluations and microscopic understanding of St–HFDA copolymers in SC-CO2.

Evaluation of CO2‐philicity and thickening capability of multichain poly(ether‐carbonate) with assistance of molecular simulations

“…In the modeled systems, polymer interactions were analyzed through the calculated parameter of free volume fraction, Flory–Huggins parameter and RDF. The previous literatures 19,33–37 provided many references to do the simulation with proper calculating methods, and many settings can be referred.…”

“…After that, five cycles of annealing process from 300 to 500 K and then back to 300 K were executed to balance energy in the system. Molecular dynamics were carried out with NPT ensemble method, and the pressure was 20 MPa while the temperature was 298 K, the thermostat method was Andersen and the barostat method was Berendsen 19,37 . The composition information in the systems is shown in Table 1.…”

“…However, polymers are very difficult to dissolve in carbon dioxide, only CO 2 ‐philic polymers can dissolve well in carbon dioxide. Currently, the most soluble polymers in carbon dioxide are fluoropolymers 19–26 and silicon polymers 27–31 . However, the costliness, environmental permanence 32 and co‐solvent demand restrict their application.…”

“…To be considered as a good carbon dioxide thickener, in addition to the solvation capability, the thickening ability is a very important characteristic. Many researchers 21,19,39 have reported that tuning the intermolecular force can be used for thickening, such as “π–π” stacking in phenyl groups can promote the thickening degree.…”

Thickening Supercritical CO2 with π-Stacked Co-Polymers: Molecular Insights into the Role of Intermolecular Interaction

“…Compared to the ab initio calculation, the molecular dynamics simulation (MD) for all atoms is more suitable for the polymer–CO 2 system and the results are more credible. Liu and Sun have explored the correlation of co-polymer structure with its solubility by MD simulations and obtained good results [ 31 , 32 , 33 , 34 ]. The microscopic information of the polymer–CO 2 system could be used to provide guidance for the exploitation of polymer thickeners.…”