Radiation crosslinked poly(acrylamide/2-hydroxypropyl methacrylate/maleic acid) and their usability in the uptake of uranium
The terpolymeric poly(acrylamide/2-hydroxy propylmethacrylate/maleic acid) (AAm/HPMA/MA) hydrogels in the rod form have been prepared by gamma radiation of quaternary mixtures of acrylamide/2-hydroxy propylmethacrylate/ maleic acid/water. Spectroscopic and thermal analyses of AAm/HPMA/MA were made. The hydrogels were used in experiments on swelling, diffusion and adsorptions of uranyl ions from aqueous uranyl acetate solutions. For the hydrogels, the parameters of swelling and diffusion were calculated. In the experiment of uranyl ions adsorption, Type L (Langmuir) adsorption isotherm in Giles classification system was found. Binding parameters such as the initial binding constant (K-i), the equilibrium binding constant (K), monolayer coverage (n), site-size (u), maximum fractional occupancy (theta) were calculated for hydrogel/uranyl ion system by using the linearization methods such as Klotz, Scatchard and Langmuir methods. Thermodynamic parameters such as adsorption free energy (DeltaG), adsorption enthalpy (DeltaH) and adsorption entropy (DeltaS) were also calculated. Finally, the effect of MA contents of the hydrogel and irradiation doses was Studied on the adsorption of uranyl ion from its aqueous solution.