Adsorption of Cesium Radionuclides by the Composite Sorbents Carbon Fiber/Transition Metals Ferrocyanides

Among various methods of cesium removal from aqueous solutions, sorption using transition metals ferrocyanides is the most efficient method due to extremely high affinity of cesium ions to ferrocyanides. The efficiency of transition metals ferrocyanides application is known to depend on the crystal size being the highest for nanocrystals. Although nanocrystals are difficult to handle in direct application, they can be used in composite materials. In this case two main problems arise: how to control the crystal size of transition metals ferrocyanides and fix them reliably in the supporting matrix. Here we suggest a new route to preparation of composite materials selective to cesium ions using transition metals ferrocyanides stabilized by siloxane-acrylate latexes. The size of transition metals ferrocyanides is controlled by the size of latex particles and their stability is determined by ionization of polyacrylic acid carboxylic groups on the functionalized latex surface. These functionalized particles can be used as precursors in preparation of composite materials by sedimentation and polymerization of latexes on the solid surface of porous matrix, e.g. carbon fibers. Several routes of preparation of carbon fiber based composite materials using functionalized latexes and sorption properties of the obtained materials are discussed. The effect of preparation conditions (method used, carbon fiber polarization potential, concentration of latexes functionalized with transition metals ferrocyanides) on cesium uptake by composite sorbents from solutions of various salinity is reported.