Molecular imprinted chitosan-TiO₂ nanocomposite for the selective removal of Rose Bengal from wastewater

A new molecularly imprinted polymer (MIP) chitosan-TiO₂ nanocomposite (CTNC) was prepared for the selective and quantitative removal of Rose Bengal dye from industrial wastewater. The physicochemical features of the prepared CTNC-MIP nanoparticles were thoroughly investigated. The prepared MIP nanoparticles exhibited high surface area (95.38m²/g) with relatively uniform mesoporous channels that allowed an exceptional uptake of the dye (q_m=79.365mg/g) and reflected the high selectivity of the prepared MIP compared to pure chitosan. The dye uptake was investigated using Freundlich, Langmuir, Dubinin Radushkevich and Temkin models. The kinetics of removal was explored by pseudo-first, pseudo second order, Elovich and Weber-Morris models. The Experimental data fitted well into pseudo-second order model, and much well with the Langmuir isotherm confirming the formation of monolayer of dye molecules. The enthalpy of adsorption was (62.279kJmol^-1) showing strong interaction of MIP with the dye. The prepared MIP exhibited a good recyclability and stability.