Analysis of microporosity in ordered mesoporous hierarchically structured silica by combining physisorption with in situ small-angle scattering (SAXS and SANS).
Analysis of microporosity in ordered mesoporous hierarchically structured silica by combining physisorption with in situ small-angle scattering (SAXS and SANS).
复制标题
通过物理吸附与原位小角散射（SAXS 和 SANS）相结合分析有序介孔分级结构二氧化硅的微孔率
DOI：
10.1021/la9013619
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发表时间：
2009
期刊：
影响因子：
--
通讯作者：
A. Timmann
中科院分区：
文献类型：
--
作者：
S. Mascotto;D. Wallacher;A. Brandt;T. Hauss;M. Thommes;G. A. Zickler;S. S. Funari;A. Timmann
结合物理吸附实验，同时在原位小角X射线和中子散射（SAXS/SANS）被用来阐明在介孔二氧化硅的孔隙率与三峰孔结构。该材料（“KLE-IL”）含有直径为14 nm的球形中孔、蠕虫状中孔（2 - 3 nm）和微孔，其由嵌段共聚物和离子液体表面活性剂模板化，而微孔源自嵌段共聚物的亲水性嵌段。该研究的主要目的是对微孔和小中孔进行量化，并找出它们是否确实位于较大的球形中孔之间。我们的原位SAXS/SANS实验利用了氮气（SANS，T= 77 K）和二溴甲烷（SAXS，T= 290 K）的对比度匹配。通过使用具有稍大的动力学直径的后一种气体，可以判断在环境条件下孔的可接近性。原位实验得到了高精度非原位物理吸附的支持。使用合适的SAXS/SANS分析方法，可以分离微孔和小中孔的含量。
The combination of physisorption experiments with simultaneous in situ small-angle X-ray and neutron scattering (SAXS/SANS) was used to elucidate the porosity in mesoporous silica with a trimodal pore structure. The material (“KLE-IL”) contains spherical mesopores of 14 nm in diameter, worm-like mesopores (2−3 nm), and micropores, templated by a block copolymer and an ionic liquid surfactant, while the micropores originate from the hydrophilic block of the block copolymer. The main objective of the study was the quantification of the microporosity and the small mesopores and to find out if they are indeed located between the larger, spherical mesopores. Our in situ SAXS/SANS experiments took advantage of contrast matching of nitrogen (SANS,T= 77 K) and dibromomethane (SAXS,T= 290 K). By using the latter gas with a slightly larger kinetic diameter, it was possible to judge the accessibility of the pores under ambient conditions. The in situ experiments were supported by high-precision ex situ physisorption. Using suitable approaches for the SAXS/SANS analysis, it was possible to separate the content of the micropores and small mesopores.