Evaluation of Getter Metals in Na–Al–Si–O Aerogels and Xerogels for the Capture of Iodine Gas

In this paper, sodium aluminosilicate aerogels and xerogels were evaluated as scaffolds for a variety of different getters including Ag + , Cs + , Cu 2+ , Fe 3+ , K + , Li + , Rb + , Sb 3+ , Sn 2+ , and Sn 4+ for the capture of gaseous iodine coming from nuclear facilities. The exchange capacities varied widely from a near complete exchange in the case of Ag + o much lower exchange levels for some of the Sn compounds [i.e., colloidal SnO 2 , Sn(II) acetate, and Sn(IV) acetate]. Several of the additives showed great promise at allowing for high iodine loadings in the base materials including the following: AgNO 3 , colloidal SnO 2 , Sn(II) acetate, Sn(IV) acetate, Cu(NO 3 ) 2 , and CuSO 4 . From the standpoint of iodine uptake as a function of getter loading, Sn 4+ was the most promising with a getter utilization (mass of iodine divided by mass of Sn, in atomic %) of 8.4, a chemical uptake of 60.7 mass % (oxygen excluded), and an m I m s -1 (mass of iodine per mass of sorbent) value of 0.881; these are some of the highest values reported to date for inorganic iodine sorbents.