Effect of Substrate Interaction on Thermodynamics of Prefreezing
Effect of Substrate Interaction on Thermodynamics of Prefreezing
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DOI：
10.1021/acs.macromol.9b01499
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发表时间：
2019-11
期刊：
影响因子：
5.5
通讯作者：
M. Tariq;Oleksandr Dolynchuk;T. Thurn‐Albrecht
中科院分区：
文献类型：
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作者：
M. Tariq;Oleksandr Dolynchuk;T. Thurn‐Albrecht
除了异质成核之外，固体表面还可以通过鲜为人知的预冷冻过程诱导液体结晶。预冻是指在材料的整体熔化温度以上在固体表面的界面处形成热力学稳定的结晶层。在这里，我们使用原位原子力显微镜对二硫化钼 (MoS2) 基材上的聚乙烯 (PE) 预冻进行了研究，这使我们能够与石墨基材上预冻 PE 的早期发现进行直接比较。实验明确表明，预冻 PE 层在 MoS2 上比在石墨上的温度范围大得多。采用新近发展起来的预冻唯象理论进行分析，结果定量地表明，较大的预冻温度范围是由较大的界面自由能差γsm – (γsc + γcm)引起的。
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).