Hydration-Induced Local Molecular Structures in Nano-Layered Clay Particles

Authors K. Sato, K. Numata

Department of Environmental Sciences, Tokyo Gakugei University, Koganei, 184-8501 Tokyo, Japan

Е-mail sato-k@u-gakugei.ac.jp
Issue Volume 5, Year 2013, Number 1
Dates Received 06 September 2012; published online 28 March 2013
Citation K. Sato, K. Numata, J. Nano- Electron. Phys. 5 No 1, 01002 (2013)
PACS Number(s) 78.70.Bj, 68.43. – h
Keywords Smectite, Clay mineral, Positronium.
Annotation Positronium (Ps) annihilation spectroscopy and thermogravimetry and differential thermal analysis (TG-DTA) were conducted for synthetic smectite clay minerals to investigate local molecular structures induced by water adsorption and desorption. The TG curves indicate the weight loss of ~ 3.5 wt %, ~ 2.5 wt %, and ~ 2.0 wt % for saponite, hectorite, and stevensite due to dehydration, in accordance with DTA endothermic peaks around 332 K, 350 K, and 345 K. It is found based on the results of Ps lifetime spectroscopy that the presence of angstrom-scale open space is sensitively dependent on water adsorption and desorption in smectite clay minerals.

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