swelling property of xanthan-g-poly(amps-aam-aac) hydrogels as a dye adsorbent

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#