Preparation of nanocomposite hydrogels with nanoclay: Characterization, swelling properties and dye adsorption behavior

Abstract

Nanocomposite hydrogel (polyacrylamide/nanoclay) was prepared by in situ free radical polymerization of acrylamide, an aqueous media with nanoclay (Laponite clay). The properties of nanocomposite hydrogels (NC) were characterized by FTIR spectroscopy, XRD patterns, and morphology of the samples was also examined by transmission electron microscopy indicated well dispersed Laponite platelets in the nanocomposite hydrogels prepared. The thermal stability was studied by thermogravimetric analysis (TGA). The swelling properties behavior of the NC were also investigated in distilled water and in saline solution at room temperature. The prepared nanocomposites hydrogels were used as adsorbent for a cationic dye, methylene blue (MB) and basic red 46 (BR) from water. The investigation of the dye adsorption capacity and rate of nanocomposite hydrogels as a function of clay content revealed that both the adsorption capacity and the rate are enhanced as the nanoclay content is increased in nanocomposite composition. The results showed that maximum adsorption capacity of methylene blue on the prepared adsorbents is 492.5 mg/g for basic red at 488.2 mg/g and adsorption is well described by Langmuir isotherm model