Effect of Graphene on Ice Polymorph

Abstract

Recently, ice with stacking disorder structure, consisting of random sequences of cubic ice (Ic) and hexagonal ice (Ih) layers, was reported to be more stable than pure Ih/Ic. Due to a much lower free energy barrier of heterogeneous nucleation, in practice, the freezing process of water is controlled by heterogeneous nucleation triggered by an external medium. Therefore, we carry out molecular dynamic simulations to explore how ice polymorphism depends on the lattice structure of the crystalline substrates on which the ice is grown, focusing on the primary source of atmospheric aerosols, carbon materials. It turns out that, during the nucleation stage, the polymorph of ice nuclei is strongly affected by graphene substrates. For ice nucleation on graphene, we find Ih is the dominant polymorph. This can be attributed to structural similarities between graphene and basal face of Ih. Our results also suggest that the substrate only affects the polymorph of ice close to the graphene surface, with the preference for Ih diminishing as the ice layer grows.

Different roles of surfaces’ interaction on lattice mismatched/matched surfaces in facilitating ice nucleation

“…Lots of experimental works on well-characterize atomic surfaces, e.g., graphene [3][4][5][6][7] and minerals [8][9][10][11] as well as molecular dynamics (MD) simulations on modeling surfaces with a series of controlled features have been employed to investigate the microscopic mechanism of ice nucleation on various material surfaces. Some plausible summaries about the nucleation effects of one (or a few) individual variable(s) of material surfaces in experience, such as the lattice templating, [12][13][14][15][16][17] the hydrophilicity-induced layering of interfacial water, [3,4,18] the hydroxyl hydrogen bonding, [19][20][21][22] as well as the nanometer carving [23][24][25] and micrometer stepping [10,26,27] were found to regulate the ice nucleation in some specific cases, but often with exception and deviation in others. For example, there is one common sense that an effective nucleating agent should provide a template for ice formation, thus the silver iodine (AgI), whose lattice constant is only 1.5% different from that of the ice Ih, is most effective in promoting the occurrence of ice nucleation for wide application in artificial rainfall.…”

Variable Angle Spectroscopic Ellipsometry Characterization of Graphene Oxide in Methanol Films

“…The remarkable electrical, thermal, mechanical, optical, and long electron mean free paths properties of graphene make it compelling for various engineering applications [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18].…”