Abstract We have compared the structure, phase transitions and the thermal motion mechanisms of the undecylenic acid in bulk and inside a porous matrix using powder X-ray diffraction, calorimetry and IR-spectroscopy methods. The matrix used was a porous silicon with cylindrical pores (D = 20 nm). The interaction between the walls of the porous silicon and the nanocrystals of the undecylenic acid results in a crystalline structure, which is significantly different from the structure of bulk undecylenic acid. A phase transition in the wall-adjacent layer of the undecylenic acid nanocrystals was shown to take place. The solid-state phase transition temperatures, as well as the melting point, were shown to be lower for nanocrystals. Topological soliton motion mechanism was suggested to explain the thermal motion of the undecylenic acid molecules in the rotator phase.

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纳米结构十一碳烯酸中热运动的结构和机制研究

摘要 我们使用粉末 X 射线衍射、量热法和红外光谱方法比较了多孔基体内部和本体中十一碳烯酸的结构、相变和热运动机制。所使用的基质是具有圆柱孔 (D = 20 nm) 的多孔硅。多孔硅壁与十一碳烯酸纳米晶体之间的相互作用导致晶体结构，其与本体十一碳烯酸的结构显着不同。显示在十一碳烯酸纳米晶体的壁相邻层中发生相变。纳米晶体的固态相变温度和熔点都较低。