Nanocomposites and nanomaterials 

Sorption properties of porous aluminosilicate minerals of Ukraine, in situ modified by poly [5- (p-nitrophenylazo) -8-methacryloxyquinoline] of toxic metal ions

Savchenko1, E. Yanovska1,  D. Sternik2, O. Kychkyruk3

1 National Taras Shevchenko University of Kyiv,
60, Volodymyrska str., 01601 Kyiv, Ukraine
E-mail: iras@univ.kiev.ua
2 Maria Curie-Skłodowska University, pl. Maria Curie-Skłodowskiej 3, 20‑031 Lublin, Poland
3 Ivan Franko Zhytomyr State University, 40 Velyka Berdychivska St., 10008 Zhytomyr, Ukraine

Porous aluminosilicate minerals of Ukraine are widely known for their adsorption properties against a number of toxic organic substances, ions of toxic metals, pathogenic bacteria, etc. However, their natural properties can be improved, in particular by fixing on their surface homo- or copolymers of different chemical nature, capable of participating in the processes of complexation or ion exchange, resulting in composite materials with valuable sorption properties.
The main methods of fixing polymers on the surface of porous inorganic carriers are physical and chemical fixation, sol-gel method and in situ immobilization, each of which has its advantages and disadvantages. We have previously found that in situ immobilization and adsorption of poly [8-oxyquinoline methacrylate] on the saponite surface of the Tashkiv deposit and clinoptilolite of the Sokyrnytsia deposit led to an increase in their sorption capacity for Pb (II), Cu (II) and Fe (III) ions.
This paper is devoted to the synthesis and study of sorption properties of ions of Pb (II), Cu (II) and Fe (III) composites based on saponite and clinoptilolite, in situ immobilized poly [5- (p-nitrophenylazo) -8-methacryloxyquinoline] (AzoQN). In situ immobilization of AzoQN on the surface of selected minerals was performed by initiated radical polymerization in the presence of mineral particles.
Immobilization of AzoQN on the surface of saponite and clinoptilolite was confirmed using IR spectroscopy and thermogravimetric analysis combined with mass spectroscopy. Using mass thermogravimetric analysis, the mass fractions of polymer in the synthesized composites were determined. And the forms of immobilized polymer on the surface of minerals were described based on the analysis of photographs of the surface of the synthesized composites obtained by scanning electron microscopy.
It was found that as a result of in situ immobilization of poly [5- (p-nitrophenylazo) -8-methacryloxyquinoline] on the saponite surface, the sorption capacity of the mineral relative to Pb (II) and Cu (II) ions increases more than 2 times. Thus, the sorption capacity of the synthesized composite relative to Pb (II) ions is 1.5 times higher than that for the saponite composite with in situ immobilized poly [8-oxyquinoline methacrylate].
An increase in the sorption capacity of the synthesized clinoptilolite-based composite relative to Cu (II) and Pb (II) ions compared to the original mineral was not recorded. However, its significant increase relative to Fe (III) ions was found to be 5.6 times. This value is 4 times higher than that for a clinoptilolite-based composite with in situ immobilized poly [8-oxyquinoline methacrylate] and three times higher than that for a clinoptilolite-based composite with adsorbed poly [8-oxyquinoline methacrylate].
The obtained results can be explained by the additional introduction of azo groups into the immobilized polymer.