Hybrid Ion Exchangers

Hybrid ion exchangers are of recent origin in the field of ion exchange chemistry. They have shown excellent chemical, mechanical and thermal stability conversant to both organic and inorganic counterparts. Very recently, new classes of ion exchangers have been studied by combining surfactants and inorganic metal phosphates. This article highlights the salient features of metal phosphates as ion exchangers, various development stages with the modifications, with an emphasis on the recent developments in the field of analytical chemistry, particularly surfactant-based hybrid fibrous and non-fibrous metal phosphates as ion exchangers. Surfactants or surface-active agents when present in the matrix of inorganic metal phosphates not only enhance their ion-exchange capacity but, also the selective adsorption of metal ions. Therefore, these materials are of great importance in industrial and environmental applications

Synthesis and characterization of a Hg(II) selective II-butyl acetate cerium(IV) phosphate as a new intercalated fibrous ion exchanger: Effect of surfactants on the adsorption behaviour

1856-1860n-butyl acetate Ce(IV) phosphate, a new Hg(II) selective, intercalated fibrous ion exchanger, has been synthesized and characterized by its ion exchange properties, thermal stability and adsorption behaviour for metal ions, X-ray, IR, TGA/DTA and SEM studies. Effect of surfactants on the adsorption behaviour of the material has also been studied. The exchanger has been found to be selective for Hg(II), hence, it can be utilized for the separation of this metal ion from other heavy metals from aqueous media. Studies on the effect of surfactants on the adsorption behaviour of this material show that for heavy metals ion, the adsorption increases with the concentration of anionic surfactants up to the CMC value and then decreases. But, for cationic, surfactants, the reverse is true. For non-ionic surfactant, adsorption remains constant up to the CMC value and then increases. For alkaline earths, the exchanger shows the same trend as above for cationic and non-ionic surfactants. However, for anionic surfactants, it is constant throughout the whole concentration range