Transmission X-ray Microscopy (TXM) Reveals the Nanostructure of a Smectite Gel

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• 作者：Marek S. Ż ; bik ; Wayde N. Martens ; Ray L. Frost ; Yen-Fang Song ; Yi-Ming Chen ; Jian-Hua Chen
• 刊名：Langmuir
• 出版年：2008
• 出版时间：August 19, 2008
• 年：2008
• 卷：24
• 期：16
• 页码：8954-8958
• 全文大小：244K
• 年卷期：v.24,no.16(August 19, 2008)
• ISSN：1520-5827

文摘

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 smectitesʼ 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.