LAUSR

Besides heterogeneous nucleation, a solid surface can induce crystallization of a liquid via the less known process of prefreezing. Prefreezing refers to the formation of a thermodynamically stable crystalline layer at an interface to a solid surface above the bulk melting temperature of the material. Using in situ atomic force microscopy, here, we present an investigation of prefreezing of polyethylene (PE) on a molybdenum disulfide (MoS2) substrate that allows us to make a direct comparison with earlier findings of prefreezing of PE on a graphite substrate. The experiments explicitly show that the prefrozen PE layer is stabilized over a significantly larger temperature range on MoS2 than on graphite. By employing the recently developed phenomenological theory of prefreezing for analysis, the results quantitatively show that the larger temperature range of prefreezing is caused by a larger interfacial free energies difference γsm – (γsc + γcm).