Organic-inorganic hybrid materials prepared by sol-gel approach have attracted a great deal of attention in material science. Organic polymeric part of the composite provides mechanical and chemical stability whereas the inorganic part supports the ion-exchange behaviour and thermal stability and also increases the electrical conductivity. Such modified composite materials can be applied as an electrochemically switchable ion exchanger for water treatment, especially water softening. Polyaniline zirconium(IV) tungstoiodophosphate nanocomposite ion exchanger is prepared by sol-gel method. Polyaniline zirconium(IV) tungstoiodophosphate nanocomposite ion exchanger is synthesized and characterized by Fourier transform-infrared spectra, ultraviolet-visible spectra, X-ray diffraction, scanning electron microscopy, thermogravimetric analysis, ion exchange, conductivity, and antimicrobial studies. A mechanism for the formation of the polyaniline zirconium(IV) tungstoiodophosphate nanocomposite ion exchanger was discussed. The route reported here may be used for the preparation of other nanocomposite ion exchangers. 1. Introduction Organic-inorganic hybrid materials prepared by sol-gel approach have attracted a great deal of attention in material science. Organic polymeric part of the composite provides mechanical and chemical stability whereas the inorganic part supports the ion-exchange behaviour, thermal stability and also increases the electrical conductivity. Such modified composite materials can be applied as electrochemically switchable ion exchanger [1, 2] for water treatment, especially water softening. The synthesis of hybrid ion exchangers with controlled functionality and hydrophobicity could open new avenues for organometallic chemistry, catalysis, organic host-guest chemistry, analytical chemistry [3–5], hydrometallurgy, antibiotic purification, separation of radioactive isotopes and large scale application in water treatment and pollution control [6, 7]. Thus, organic-inorganic hybrid materials are expected to provide many possibilities as new composite materials. Accordingly, the hybrid can be used to modify organic polymer materials or to modify inorganic glassy materials. In addition to these characteristics, the hybrid materials can be considered as new composite materials that exhibit very different properties from their original components, that is, organic polymer and inorganic materials especially in the case of molecular level hybrids. Thus, the synthesis of polymeric/inorganic composites has received a great deal of attention because it
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