Recently, Jianjun Wang's research team from Institute of Chemistry, Chinese Academy of Sciences, published a paper in《Nature》named "Probing the critical nucleus size for ice formation with graphene oxide nanosheets".

Water freezing is ubiquitous and affects areas as diverse as climate, the chemical industry, cryobiology and materials science. Ice nucleation is the controlling step in water freezing and has, for nearly a century, been assumed to require the formation of a critical ice nucleus. But there has been no direct experimental evidence for the existence of such a nucleus, owing to its transient and nanoscale nature. Here we report ice nucleation in water droplets containing graphene oxide nanosheets of controlled sizes and show that they have a notable impact on ice nucleation only above a certain size that varies with the degree of supercooling of the droplets. We infer from our experimental data and theoretical calculations that the critical size of the graphene oxide reflects the size of the critical ice nucleus, which in the case of sufficiently large graphene oxides sits on their surface and gives rise to ice formation behaviour consistent with classical nucleation theory. By contrast, when the graphene oxide size is smaller than that of the critical ice nucleus, pinning at the periphery of the graphene oxide deforms the ice nucleus as it grows. This gives rise to a much higher free-energy barrier for nucleation and suppresses the promoting effect of the graphene oxide. The results provide experimental information on the existence and temperature-dependent size of the critical ice nucleus, which has previously only been explored theoretically and through simulations.

In their paper, they used graphene oxide dispersion which from XFNANO, it is a great honour for XFNANO and we will work hard to research more products.