Shape and volume of cavities in thermoplastic molecular sieves based on syndiotactic polystyrene
Shape and volume of cavities in thermoplastic molecular sieves based on syndiotactic polystyrene
复制标题
间规聚苯乙烯热塑性分子筛的空腔形状和体积
DOI：
10.1021/cm001089a
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发表时间：
2001
影响因子：
8.6
通讯作者：
D. Sannino
中科院分区：
文献类型：
--
作者：
G. Milano;V. Venditto;G. Guerra;L. Cavallo;P. Ciambelli;D. Sannino
通过数值程序评估间规聚苯乙烯 (s-PS) 不同结晶相和笼形相中的空隙空间。结果表明，δ 型是纳米多孔的，每个晶胞包含两个相同的空腔，其形状和体积具有特征。由于包合，δ形式的晶胞被扩大，并且空腔能够包含明显大于其起始尺寸的分子。还介绍了不同晶型 s-PS 粉末在 77 K 下的氮气吸附实验。这些可以通过 δ 晶相的每个空腔包含三个氮分子来解释，从而给出其体积的独立估计。
The empty space in different crystalline and clathrate phases of syndiotactic polystyrene (s-PS) is evaluated by a numerical procedure. It is shown that the δ form is nanoporous and includes two identical cavities per unit cell, whose shape and volume are characterized. As a consequence of clathration, the unit cell of the δ form is enlarged and the cavity is able to include molecules definitely larger than its starting size. Sorption experiments of nitrogen at 77 K for s-PS powders in different crystalline forms are also presented. These can be interpreted by inclusion of three nitrogen molecules per cavity of the δ crystalline phase and hence give an independent estimate of its volume.