Preparation and characterization of new organoclays using natural amino acids and Cloisite Na+

In this investigation, several simple positively charged natural amino acids were used for organo-modification of unmodified Cloisite Na+ montmorillonite. Different a-amino acid molecules such as: L-alanine, L-valine, L-leucine, L-isoleucine, L-phenylalanine as well as L-methionine and Cloisite Na+ were used for the preparation of the novel organoclays by an intercalation reaction in an aqueous solution. The intercalated materials were characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA). Fourier transform infrared spectroscopy, dispersibility measurement, scanning electron microscopy, field emission scanning electron microscopy and transmission electron microscopy. According to the XRD patterns of the samples, the intercalation of amino acids was successful as the increased basal spacing confirmed. TGA characterization and analysis showed that the amount of organic modifier in the organo-modified clays is in good agreement with the theoretically calculated stoichiometric content. The intercalated organic amino acid ions make these novel clays organophile, biocompatible and biodegradable. (c) 2010 Elsevier B.V. All rights reserved.