Abstract
A new poly(methacrylic acid-co-itaconic acid) [poly(MAA-co-IA)] hydrogel encapsulated copper hexacyanoferrate (CuHCF) nanoparticles was synthesized. The prepared samples were characterized by Fourier-transform infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray, transmission electron microscopy, X-ray diffraction, and thermogravimetric analysis-differential scanning calorimetry. The prepared composite CuHCF/poly(MAA-co-IA) was examined for adsorption of Cs+ by batch technique. The effect of various factors like solution pH, Cs+ initial concentration, agitation time, the temperature of the solution, and competition ions was investigated. CuHCF/poly(MAA-co- IA) composite exhibited high adsorption capacity (1.48 mmol g(-1)) of Cs+ occur at a pH equal to 9, initial concentration of 8 mmol L-1 Cs+ at room temperature (25 degrees C). The adsorption of Cs+ was kinetically rapid, and the equilibrium was reached within 40 min. Between Langmuir, Freundlich, Temkin, and Dubinin- Radushkevich isotherms models, the data were well fitted with the Langmuir model, suggesting that the uptake of Cs+ was monolayer and homogeneous. The adsorption kinetics parameters were fitted well to the pseudo-second-order model, and the Elovich equation indicated that chemisorption is the predominant adsorption mechanism. The intraparticle diffusion model shows that more than one controlling step may influence Cs+ loading. Thermodynamic parameters were calculated in the temperature range of 25 degrees C- 55 degrees C and revealed that Cs+ sorption was endothermic, spontaneous, and more favourable at the higher temperature. The selectivity of the composite for Cs+ in the existence of Na+ and K+, Li+, Ca++ Mg++ ions was exceptional. Up to 98% desorption of Cs+ was completed with 2M KCl.