Adsorption Potential of Cationic Dyes Through Functionalized Sterculia Gum Based Conducting Hydrogel Matrix

Abstract

The detrimental effect of untreated textile effluents on environment especially water quality is a major concern in current scenario. The development of ecofriendly adsorbents for water treatment is a major fascinating and challenging area which has gained huge impetus in recent years. The present study aims to synthesize novel Sterculia gum (SG) crosslinked electric responsive hydrogel and further studies, to investigate its efficiency for enrichment of toxic cationic dyes, methylene blue (MB), crystal violet (CV), and malachite green (MG). The novel SG-g-PNIPAM/PAAm/PANI hydrogel matrix was fabricated through graft copolymerization using dual vinylic monomers and in-situ incorporation of aniline within the polymer matrix and characterized by Fourier transform infrared spectrometer (FTIR), thermogravimetric analysis (TGA), differential thermal analysis (DTA), and scanning electron microscopy (SEM). Electrical conductivity was measured using four-probe technique. The impact of reaction parameters on dye enrichment such as contact time, pH, and temperature was assessed. The dye adsorption capacity through hydrogel matrix followed Temkin isotherm model, Ho pseudo second order kinetics, and multistep Weber and Morris intraparticle diffusion. The adsorption capacity (adsorption efficiency) of the synthesized hydrogel matrix was ascertained as 17.413 (85.07%), 17.985 (88.93%), and 16.703 mg/g (83.17%) for MB, MG and CV, respectively. This matrix proved highly efficient adsorbent for dye enrichment studies.