PHYSICO-CHEMICAL AND SORPTION PROPERTIES OF NANOCOMPOSITE AEROGELS BASED ON MODIFIED CARBON NANOTUBES AND GRAPHENE

The paper presents the technology for obtaining nanocomposite aerogels based on oxidized carbon nanotubes (o-CNTs) , reduced graphene oxide (r-GO) modified with polyaniline and phenoldehyde resin. Aerogel was obtained in high-pressure autoclave among supercritical fluid -isopropanol. The complex diagnostic of synthesized nanocomposite was carried out by the methods of scanning and transmission electron microscopy, infrared spectroscopy, X-ray diffractometry, Raman spectroscopy. The parameters of the porous space were evaluated by adsorption of nitrogen. The resulting electron images indicate that the CNTs was as structural formers, concentrating on their surface graphene sheets. It should also be noted that in the samples, particles of spherical polyaniline were found. It was established that nanocomposite aerogel is a mesoporous material with a specific surface of 289 m2/g. A comparison of infrared and Raman spectra, as well as X-ray diffractograms of the initial materials with aerogel spectra was carried out. According to the results, the nanocomposite contains combined peaks of all source materials. After drying in the supercriti-cal isopropanol media, the ordered structure of the carbon frame is preserved. Electronodononic oxygen and nitrogen-containing groups, which are identified according to the IR spectroscopy as part of the composite, can be active centers for adsorption of heavy metals due to the possibility of the formation of coordination bonds. The nanocomposite sorption activity was evaluated by the example of the heavy metals sorption, namely lead, from model aqueous solutions. To determine the contact time and the absorption mechanism, kinetic studies of adsorption were carried out in a limited volume. It was found that 99% of the pollutant was sorbed in the first 15 min with an achievement of the adsorption capacity of 350 mg/g. Using of pseudo-first and second-order mod-els, the Elovich model and intra-particle diffusion models the adsorption mechanism were offered.