Dehydration transformation in Ca-montmorillonite

Bulletin of materials science

P Bala¹  B K Samantaray¹  S K Srivastava² 

[1] Department of Physics and Meteorology, Indian Institute of Technology, Kharagpur 721 302, India$$Department of Physics and Meteorology, Indian Institute of Technology, Kharagpur 721 302, IndiaDepartment of Physics and Meteorology, Indian Institute of Technology, Kharagpur 721 302, India$$;Department of Chemistry, Indian Institute of Technology, Kharagpur 721 302, India$$Department of Chemistry, Indian Institute of Technology, Kharagpur 721 302, IndiaDepartment of Chemistry, Indian Institute of Technology, Kharagpur 721 302, India$$

关键词: Montmorillonite;    layer disorder;    microstructure parameters.;   

DOI  :  

学科分类：材料工程

来源: Indian Academy of Sciences

【 摘 要 】

The present work deals with the dehydration transformation of Ca-montmorillonite in the temperature range 30°�??500°C. Thermal, infrared (IR), and X-ray diffraction (XRD) analyses were used to describe the thermal transformation. The microstructural and layer disorder parameters like crystallite size, r.m.s. strain ($langle e^2angle^{1/2}$), variation of interlayer spacing (�??), and proportion of planes which were affected by the defect (�?), have all been calculated from the (001) basal reflection using the method of variance and Fourier line shape analysis. These investigations revealed that sample underwent transformation from hydrated phase to dehydrated phase at 200°C, and as a consequence, its basal spacing collapsed from 16.02 �? (30°C) to around 10 �? (200°C). This transformation occurred through a wide range of temperature, i.e. within the range 120°�??200°C. The crystallite size was maximum at room temperature (30°C), however, the size decreased with increasing temperature in the hydrated phase, whereas the size increased with increasing temperature for the dehydrated phase. The �??, �? and $langle e^2angle^{1/2}$ of the hydrated and the dehydrated phase increased and decreased, respectively with increase of heating temperature.

【 授权许可】

Unknown