Melting and crystallization in thin film of n-alkanes: A molecular dynamics simulation
Melting and crystallization in thin film of n-alkanes: A molecular dynamics simulation
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DOI：
10.1063/1.1287062
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发表时间：
2000-08
影响因子：
4.4
通讯作者：
T. Shimizu;Takashi Yamamoto
中科院分区：
文献类型：
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作者：
T. Shimizu;Takashi Yamamoto
最近发现的正烷烃和正醇在熔体自由表面的异常结晶表明有必要更深入地了解结晶的分子机制。借助大规模分子模拟，利用简化的珠弹簧分子模型，直接观察到正构烷烃薄膜中的熔化和结晶的分子过程。研究发现薄膜的熔化很大程度上受其表面状态的影响。当表面链垂直于表面时，薄膜更稳定，链端在表面上具有明显的优先性。通过熔体快速和缓慢冷却的结晶显示出在自由表面上形成单分子层。通过缓慢的逐步冷却，可以清晰地再现堆叠片层的逐层生长。对所涉及的分子过程的详细检查表明，单层细胞的分子机制存在相当大的差异...
Recent discovery of the anomalous crystallization in n-alkanes and n-alcohols at the free surfaces of melts has revealed the necessity for much deeper understanding of the molecular mechanism of crystallization. With the aid of large-scale molecular simulation, and by use of a simplified molecular model of bead spring, the molecular processes of melting and crystallization in a thin film of n-alkane are directly observed. It is found that melting of the thin film is greatly influenced by its surface state. The film is more stable when the surface chains are lying perpendicular to the surface, on which the chain ends have marked preference. Crystallization by both rapid and slow cooling of the melt is shown to give rise to a formation of monolayers on the free surfaces. By slow stepwise cooling, the layer-by-layer growth of stacked lamellae is clearly reproduced. Detailed inspection of the molecular processes involved shows that there are considerable differences in the molecular mechanisms of monolayer fo...