Swelling property of xanthan-g-poly(AMPS-AAm-AAc) hydrogels as a dye adsorbent
Volume Title: 1
1Chemical Engineering Department, Engineering Faculty, University of Guilan, Rasht, Iran
2Petroleum Engineering Department, Chemistry &amp; Chemical Engineering Research Center of Iran, 14335-186, &lrm;Tehran, Iran
A series of hydrogels based on Xanthan gum (XG) as a backbone and also monomers including acrylamide (AAm), acrylic acid (AAc) and 2-acrylamido-2-methylpropanoesulfonicacid (AMPS) were prepared by free-radical copolymerization for removal of Methylene blue (MB) as a cationic dye from aqueous solution. The effect of AAc, AAm and MBA concentrations on the swelling and adsorption capacitiy were investigated. The smooth surface of optimal hydrogel was firstly characterized by scanning electron microscopy (SEM), and in order to confirm its 3D structure, environmental scanning electron microscopy (ESEM) was carried out. The equilibrium swelling ratio (ESR), removal efficiency (%R), equilibrium time (teq ) and adsorption capacity (q) for MB were found in the range (3.84-17.15) g/g, (78.01-92.10)%, (480-1080) min and (2.54-3.71) mg/g, respectively. The XG-g-poly(AMPS-AAm)b hydrogel with three-dimensional structure, maximum amount of ESR, %R , q and Minimum amount of (teq) was suggested as the optimal hydrogel for removal of MB from aqouse solution. It indicated that the swelling results were as efficient as adsorption studies.