Zbik Marek S, Martens Wayde N, Frost Ray L, Song Yen-Fang, Chen Yi-Ming, Chen Jian-Hua
Inorganic Materials Research Program, School of Physical and Chemical Sciences, Queensland University of Technology, 2 George Street, GPO Box 2434, Brisbane Qld, Australia.
Langmuir. 2008 Aug 19;24(16):8954-8. doi: 10.1021/la800986t. Epub 2008 Jul 12.
The unusual behavior of smectites, the ability to change volume when wetted (swelling) or dried (shrinking), makes soil rich in smectites very unstable and dangerous for the building industry because of the movement of building foundations and poor slope stability. These macroscopic properties are dominated by the structural arrangement of the smectites' finest fraction. Here, we show in three dimensions how the swelling phenomenon in smectite, caused by a combination of hydratation and electrostatic forces, may expand the dry smectite volume not 10-fold, as previously thought, but to more than 1000-fold. A new technique, transmission X-ray microscopy, makes it possible to investigate the internal structure and 3-D tomographic reconstruction of clay aggregates. This reveals, for the first time, the smectite gel arrangement in the voluminous cellular tactoid structure within a natural aqueous environment.
蒙脱石的异常行为，即遇湿（膨胀）或干燥（收缩）时会改变体积，这使得富含蒙脱石的土壤对建筑业来说非常不稳定且危险，因为建筑基础会移动且边坡稳定性差。这些宏观特性由蒙脱石最细颗粒的结构排列所主导。在此，我们通过三维展示了由水化作用和静电力共同引起的蒙脱石膨胀现象，如何使干燥蒙脱石的体积扩大，并非如之前所认为的10倍，而是超过1000倍。一种新技术，即透射X射线显微镜，使得研究粘土聚集体的内部结构和三维断层重建成为可能。这首次揭示了在天然水环境中，大量蜂窝状触变结构内的蒙脱石凝胶排列。
