Three scenarios of freezing of liquid marbles

Controlled freezing of water marbles coated with various hydrophobic powders was studied in situ. Three main pathways of freezing were registered, namely: i) freezing accompanied with the formation of the conical “freezing tip” singularity; ii) freezing keeping the initial spherical shape of the marble; iii) freezing resulting in the formation of flattened axisymmetric crystallized puddles. The mathematical model of freezing is reported. Qualitative analysis of marbles’ deformation under cooling is supplied. The effective surface tension of the studied water marbles is established experimentally. Thermal and elastic properties of water marbles, which are close for the studied marbles, are not responsible for the observed diversity of the freezing pathways. De-pinning of the contact line governs to the much extent the eventual shape of the frozen water marble. Strong pinning of the contact line promotes the formation of the “freezing tip singularity”; whereas, weak pinning results in the formation of flattened, oblate spheroid-like eventual shapes of the frozen water marbles.