The entrapment of UO22+ in mesoporous MCM-41 and MCM-48 molecular sieves

Abstract

A method based on direct template-ion-exchange was employed for the entrapment of UO2þ 2 ions in MCM-41 and MCM-48 molecular sieves via swapping of cetyltrimethylammonium cations present in the mesoporous channels by the UO22+ ions in an aqueous solution. The samples were characterized by XRD,FT-IR,and ICP-AES techniques. The entrapment of UO22+ ions is facilitated by the large pore size vis-a-vis the high surfactant content in the as-synthesized host materials. A higher loading of UO22+ ions was achieved in MCM-48 as compared to MCM-41,which could be attributed to its three-dimensional pore system and higher surfactant-to-silica ratio. FT-IR results provide an evidence of a strong binding of UO22+ groups with the defect silica sites of mesoporous molecular sieves.