Characterization and application of radiation grafted membranes in waste treatment

Ionic membranes were prepared by radiation-induced grafting of acrylic acid onto low density polyethylene films. To elucidate the possibility of pract ical use, a study has been made for the characterization of the grafted and chemically treated membranes. The selectivity of such prepared membranes t owards the chelation or complexation of different alkali metals was investi gated, to find that the higher affinity is observed for K+, Na+ and Li+ ion s compared to other alkali metals used. The metal uptake percent was determ ined using different techniques: flame photometer and X-ray fluorescence (X RF). The uptake of metal from its feed solution by the grafted membrane inc reased as the degree of grafting increased, i.e., it is directly proportion al to the content of functional carboxylic acid groups in the graft copolym er. As a consequence, the electrical conductivity of metal feed solution de creased during such process of metal chelation by the membrane. The higher the grafting degree of membrane, the lower the electrical conductivity of m etal feed solutions observed. The changes in thermal properties of the prep ared membranes were investigated and characterized using differential scann ing calorimeter (DSC), and thermal gravimetric analysis (TGA). The thermal stability of these membranes increased with a degree of grafting due to the formation of crosslinked network structure via hydrogen bonding. Furthermo re, such stability is enhanced for the alkali-treated membranes even at hig h elevated temperatures. The prepared membranes showed a great promise for possible use in the recovery of uranium from zirconium in their wastes.