Experimental evidence of formation of a new phase in supercooled liquid 2-biphenylmethanol
Experimental evidence of formation of a new phase in supercooled liquid 2-biphenylmethanol
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过冷液体 2-联苯甲醇中形成新相的实验证据
DOI：
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发表时间：
2006
期刊：
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通讯作者：
A. Pietraszko
中科院分区：
文献类型：
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作者：
J. Baran;N. Davydova;M. Drozd;A. Pietraszko
本文首次报道了用差示扫描量热法和X射线衍射法研究过冷液体分子化合物2-联苯甲醇中新相的形成。据发现，在交叉温度Tc <$1.2 Tg内的过冷液体亚稳团簇（核）开始出现的分子排列在不同的方式比稳定相。亚稳态核在室温下发展成宏观尺寸的团簇。在晶化温度308 K下退火10 min后，合金完全晶化为新的亚稳相。新相的结构，从X射线实验中推断，由氢键键合的分子链组成，与稳定相的结构相反，在稳定相中，分子连接成环状四聚体。
We report for the first time the formation of a new phase in a supercooled liquid molecular compound 2-biphenylmethanol by differential scanning calorimetry and x-ray diffraction measurements. It is found that at a crossover temperature Tc∼1.2 Tg within a supercooled liquid metastable clusters (nuclei) start to appear where molecules are arranged in a different way than the stable phase. The development of the metastable nuclei into clusters of macroscopic size occurs at room temperature. Full crystallization into the new metastable phase happens after annealing for 10 min at the temperature of crystallization, 308 K. The structure of the new phase, as deduced from x-ray experiments, consists of hydrogen-bonded chains of molecules, contrary to the structure of the stable phase in which the molecules are joined into cyclic tetramers.