Mascotto Simone, Wallacher Dirk, Brandt Astrid, Hauss Thomas, Thommes Matthias, Zickler Gerald A, Funari Sérgio S, Timmann Andreas, Smarsly Bernd M
Institute of Physical Chemistry, University of Giessen, Heinrich-Buff-Ring 58, D-35392 Giessen, Germany.
Langmuir. 2009 Nov 3;25(21):12670-81. doi: 10.1021/la9013619.
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.
将物理吸附实验与同步原位小角X射线和中子散射（SAXS/SANS）相结合，用于阐明具有三峰孔结构的介孔二氧化硅中的孔隙率。该材料（“KLE-IL”）包含直径为14 nm的球形介孔、蠕虫状介孔（2-3 nm）和微孔，由嵌段共聚物和离子液体表面活性剂模板化，而微孔则源自嵌段共聚物的亲水嵌段。该研究的主要目的是对微孔和小介孔进行定量，并确定它们是否确实位于较大的球形介孔之间。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）的对比匹配。通过使用动力学直径稍大的后一种气体，可以判断在环境条件下孔的可及性。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，可以分离出微孔和小介孔的含量。
