Co-grafting of acrylamide and vinyl imidazole onto EB pre-irradiated silanized silica gel

Silica-based adsorbent was prepared by radiation-induced grafting of acrylamide (AAM) and vinyl imidazole (VIM) onto the silanized silica. The silanized silica was pre-irradiated by electron beam and then reacted with AAM/VIM mixture solution under various conditions. FTIR, TG-DTA and XPS spectra manifested that AAM and VIM were successfully grafted onto the silica surface. The effects of monomer composition, absorbed dose, reaction time and reaction temperature on the grafting yield were investigated to optimize the reaction conditions. The results showed that the optimal reaction conditions were as follows: AAM/VIM mole ratio 6:4 with a total concentration of 4 mol/L, absorbed dose 100 kGy, reaction temperature 60 °C and reaction time 18 h. The SS-g-AAM/VIM adsorbent is expected to be useful for the removal of heavy-metal-ions from wastewater.

► AAM and VIM were co-grafted to silanized silica by EB pre-irradiation grafting. ► The grafted chain was characterized by thermo-analysis, FTIR and XPS. ► Physical adsorption of monomer to silica plays an important role in radiation grafting.