New organo-mineral materials based on silica gels modified in situ with nitrogen-containing polymers: synthesis and adsorption properties for Pb(ІІ), Сu(ІІ), Cd(II), and Fe(III) ions

Abstract

Three new organo-mineral composite materials were obtained by in situ immobilization of polymers containing azo-, nitro-, and oxyquinoline groups in various combinations on the surface of silica gel. The fact of modification of the silica gel surface by nitrogen-containing polymers was confirmed by IR spectroscopy and thermogravimetric analysis combined with mass spectrometry. The SEM-photo analysis of the surface of the synthesized composites allows us to state that all in situ immobilized polymers are on the surface of silica gel in the form of individual convex formations that practically do not affect the structure of the original silica gel. Regarding Fe(III) cations, all composites showed an increase in sorption capacity by 4.5–6.4 times compared to the original silica gel and did not reveal additional sorption activity compared to the original silica gel for Cd(II) and Pb(II) ions. Regarding Cu(II) ions, an increase in the sorption capacity by more than five times compared to the original silica gel was observed for the composite with in situ immobilized poly-5-(4-nitro)phenylazo-8-methacryloxyquinoline only.