Interaction between hydroxyl group and water saturated supercritical CO2 revealed by a molecular dynamics simulation study

Molecular dynamics simulations were performed to investigate hydroxyl groups-CO2 interactions. Three silica surfaces with different hydroxyl group structures were selected and the effect of pressure was studied in the range of 4.8-32.6 MPa. Radial distribution functions especially for OsOc pair show evidence for hydrogen bonds between hydroxyl groups and CO2 molecules. The hydrogen bonds structure was analyzed using the mean number of hydrogen bonds. Pressure and hydroxyl group structures were found to affect H-bonding structure. These findings provide new insight for CO2-hydroxyl group interactions to better understand the effects of CO2 in carbon capture and sequestration process.