Abstract
Classical molecular dynamics simulations and potential of mean force calculations were performed to study (1) the adsorption of several reactive oxygen species (ROSs, namely · OH, · HO2 and H2O2) on atmospheric air/ice interfaces and (2) the growth of ice from supercooled aqueous solutions of these ROSs. Free energy minima were observed for these ROSs at the air/ice interfaces. The presence of ROSs in supercooled water during the freezing process leads to the formation of quasi-liquid layers (QLLs) that were thicker than those formed from freezing of pure supercooled water. The ROSs in the supercooled water were always displaced to the air/ice interface during the freezing process at 270 K, but if the freezing process is carried out at 260 K, a significant fraction of hydroperoxy and hydrogen peroxide become trapped by the growing ice lattice. We also studied freezing of supercooled aqueous solutions containing ROSs and benzene, with 1-octanal at the interfaces with air. The structure of ice is not significantly altered by hydroperoxy, hydrogen peroxide, or benzene being trapped in the ice lattice. The presence of 1-octanal at the interfaces does not alter the trends described above; however, thinner QLLs are formed after the freezing process, and 1-octanal tends to slow down the dynamics of ROSs and aromatics at the air/ice interface.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have