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Preparation, characterization and ion-exchange properties of a new 'organic-inorganic' composite cation exchanger polyaniline silicotitanate: Its applications for treatment of hazardous metal ions from waste solutions

I.M.El-Naggar, K.A.Hebash, E.S.Sheneshen, E.A.Abdel-Galil

Polyaniline silicotitanate an ‘organic–inorganicÂ’ composite material, was prepared via sol–gel mixing of organic polymer polyaniline into the matrices of the inorganic precipitate of silicotitanate. The physico-chemical properties of this hybrid material were determined using atomic absorption spectrophotometry (AAS), CHN elemental analysis, ICPS, X-ray (XRD and XRF), IR, TGA-DTA and scanning electron microscopy (SEM). The data obtained proposed that the chemical formula of polyaniline silicotitanate may be written as: [Ti4O9H7Si + (– C6H5NH–)] 4H2O. Ion-exchange capacity (IEC), thermal stability and distribution behavior, etc.were also carried out to understand the cation-exchange behavior of the material. On the basis of distribution studies, the material was found to be highly selective for Cs+ and the selectivity sequence for sorption of Co2+, Cu+2, Cd2+, Cs+ and Pb2+ ions on polyaniline silicotitanate was found to be; Cs+> Pb2+> Co2+> Cu2+ > Cd+2. Thermodynamic parameters (i.e. ÄGo, ÄSo and ÄHo) have also been calculated for the adsorption of Co2+, Cu+2, Cd2+, Cs+ and Pb2+ ions on polyaniline silicotitanate showing that the overall adsorption process is spontaneous and endothermic.