Preparation and characterization of amino acid-modified nanoclay

Abstract

Clays are low-cost, naturally occurring nanoparticles of inorganic origin, which could be isolated through careful experimental techniques. Functional intercalation of nano clay particles is aimed at attaching new functionalities for a broader application. Nanoclay was isolated and subsequently, activated using H₃PO₄ to increase the surface porosity and then, modified using phenylalanine/aspartic acid. The modified product was characterized using Fourier transform infrared spectroscopy (FT-IR), Scanning electron microscopy (SEM), X-ray fluorescence (XRF), and thermogravimetry analysis (TGA/DTG). The SEM results show that the nanolayers were partially eroded, due to the acid activation. Other features observed were plate stacking, cracks, plate-like layers, and particle clustering, which was due to agglomerations. The smooth surface observed was due to the hydrophobic groups of the intercalates. TGA/DTG revealed that the modified product was thermally stable, due to the presence of nanolayers, which protected the amine group and thus, enhanced their thermal stability up to 250 ^oC. The maximum decomposition temperature reached was around 420-480 ^oC. In conclusion, nanoclay particles have been synthesized and subsequently, intercalated using essential and non-essential amino acids. The thermal stability of the new functional moieties was enhanced. The implication is that such materials could find useful applications as novel adsorbents for water treatment, as well as for the formulation of high-temperature polymers for automobile and other applications.