Hydrogel with high laponite content as nanoclay: swelling and cationic dye adsorption properties

Abstract

Superadsorbent poly (acrylamide-co-itaconic acid)/nanoclay hydrogels were prepared by in situ free-radical polymerization of acrylamide and itaconic acid in an aqueous media with nanoclay as a crosslinker. The properties of nanocomposite hydrogels (NCHs) were characterized by FTIR spectroscopy, XRD patterns, and TGA thermal methods. Morphology of the samples was also examined by scanning electron microscopy. The swelling properties and cationic dye adsorption behaviors of the NCHs were also investigated. The adsorption behavior of the cationic dyes such as methylene green (MG), methylene blue (MB), and crystal violet (CV) were studied on the NCHs. The effects of the clay content of the hydrogel on its cationic dye uptake behavior were studied. The adsorption studies indicated that the rates of dye uptake by the NCHs increased in the following order: MG > MB > CV. The effect of time on the different dye adsorption by the NCH was nearly the same. The NCHs may be considered as a good candidate for environmental applications to retain more water and to remove dyes.