Chitosan biopolymer based nanocomposite hydrogels for removal of methylene blue dye

Abstract

Nanocomposite hydrogels were synthesized by γ-radiation-induced copolymerization and crosslinking of Chitosan biopolymer (CS), acrylic acid (AAc) and TiO2 nanoparticles (CS-PAAc/TiO2). The structure, morphology, and properties of the nanocomposites were investigated using Fourier-transform infrared spectroscopy, X-Ray Diffraction, Scanning electron microscopy, Transmission electron microscopy, and thermogravimetric analysis techniques. The nanocomposites hydrogel was used for the removal of methylene blue dye (MB) from wastewater. It was found that the presence of TiO2 in the copolymeric matrix enhances the adsorption by increasing the physical interaction between the dye molecules and the adsorbent surface. The removal percentage increases with the increase in pH of the medium of all investigated samples and the maximum value is obtained at the solution pH is 10. The maximum adsorbent dosage for CS-PAAc/TiO2 nanocomposites is 0.20 g and for CS-PAAc hydrogel is 0.15 g per liter of the adsorbate. This study revealed that the loading of TiO2 nanoparticles into the polymeric matrix of CS-PAAc does a remarkable increase in the removal parentage of MB dye from its aqueous solution.