Ever heard of „surface freezing“ and its romantic background? This phenomenon,
which arguably constitutes one of the most simple molecular self-assembly processes in nature, refers to the spontaneous formation of a microscopically thin, crystalline layer floating on top of the melt close to, but above the freezing temperature of the bulk liquid. Capillary filling experiments on molten wax in tiny pores (only a few nanometers across), published today in Physical Review Letters, testify that this collective orientational molecular ordering is also observable at advancing, highly curved liquid menisci self-propelled by capillarity in silica pores. There you may call it “meniscus freezing” and it significantly affects the imbibition dynamics in the mesoporous matrix.