(757c) Impact of Surfaces Charge Distribution on the Mechanism of Heterogeneous Ice Nucleation

Understanding the role played by solid surfaces in ice nucleation is a significant step toward designing surfaces that can control ice nucleation. This is relevant to various fields such as atmospheric chemistry, transportation and food industry. Our overall goal is to explain the mechanisms through which surfaces affect ice nucleation and growth. Such understanding can guide the development of predictive models correlating surface properties, and interfacial water structure and dynamics to the probability of ice nucleation on that surface. To this end, in the present study we focus on the effect of surface charge distribution on the ice nucleating ability of silver iodide (AgI) surfaces. AgI is one of the most potent ice nucleating agents and has been used for cloud seeding. Our simulations indicate that the ice nucleation rate is significantly affected by the charge distribution of the surface. We can explain these effects by considering the effects of surface charges on the interfacial water orientations near the different surfaces. Our results indicate that in addition to lattice spacing, other factors such as charge distribution play a critical role in determining the ice nucleation efficiency of a surface. We further extend this understanding to elucidate the ice nucleating efficiency of mineral surfaces such as kaolinite.