Characterization of locally available Montmorillonite clay using FTIR technique

Abstract

Montmorillonite (MMT) is a layered silicate clay which belongs to the smectite clay group with a wide range of applications in medicine, polymer industry, ceramic industry and nano materials. This research is focused on the use of Fourier Transform Infrared Spectroscopy (FTIR) technique to identify and characterize Montmorillonite clay deposits available in the dry zone of Sri Lanka. Apart from identification, FTIR can be used to discover the family of minerals to which the specimen belongs, the nature of isomorphic substituent and the distinction of molecular water from constitutional hydroxyl. Clay samples obtained from several locations within the dry zone of Sri Lanka were purified, treated and subjected to FTIR, X-ray Diffraction (XRD) and Differential Thermal Analysis (DTA). To further strengthen the findings, specimens of commercially available MMT and Bentonite were subjected to the same tests. Peaks of the resultant spectrum were analyzed and compared with published literature. Results revealed that the specimens subjected to the tests contained MMT with kaolinite. In-depth study of absorbance level of each specimen was useful in identifying the exchangeable cations present in MMT. Further study of the spectrum could pave the way for quantitative analysis of these clay minerals.