Composite materials based on amino-containing humic acids with the introduction of carbon nanotubes, capable of molecular recognition and selective binding of a target metal, were obtained using molecular imprinting, and their composition and physicochemical properties were studied.

Бас редактор: ЖҰРЫНОВ Мұрат Жұрынұлы, химия ғылымдарының докторы, профессор, ҚР ҰҒА академигі, Қазақстан Республикасы Ұлттық ғылым академиясының президенті, АҚ «Д.В.Сокольский атындағы отын, катализ және электрохимия институтының» бас директоры (

We obtained modified humic acid-based cross-linked composite pre-tuned to the sorbed copper ion. The composite synthesis had three stages. At first, we obtained prepolymerization complex using humic acids iso-lated from Shubarkol deposit oxidized coals and multi-walled carbon nanotubes (MWCNTs) with template (CuSO4). We used ultrasonic activation for uniform dispersion of multi-walled carbon nanotubes. Second stage comprised copolymerization in the presence of amine and cross-linker; here the prepolymerization composite complex with the template was fixed in certain nodes of polymer network. At the third stage, acid hydrolysis destroyed the bonds of the template with the composite macromolecules, the template was re-moved, and imprints complementary to the template in shape, size, and functionality were formed and re-tained “molecular memory”. Such tuning forms adsorption centers in the polymer network of the composite, which can repeatedly and highly specifically interact with the template, and highly selectively extract target molecules from solution, leading to significant increase in sorbent capacity. The reaction was controlled by direct and back titration, and added amine, which was determined using Elementar Unicube elemental ana-lyzer. The crosslinked composite can be used as a selective sorbent tuned to a specific metal ion.

The article presents the results of a study of the synthesis of composite materials based on coal waste combined with coal and polymer raw materials, using ultrasonic chemistry methods and determining the possibility of their use as an active mineral additive for replacing part of cement in fine-grained concrete. By varying the composition of the matrix and the filler, a composite material is obtained whose properties are quantitatively and qualitatively different from the properties of each of its components. As a filler in the composition of the composite material, burned rock is used - the product of oxidative self-firing of waste rock, extracted together with coal to the surface. Burned rocks contain an organic part (unburned carbonaceous impurities) and a mineral part (calcined clay-sandy part). Features of the material composition of burned rocks, coal industry waste allows us to consider them as secondary mineral raw materials. The binder in the composite material used is thiourea-formaldehyde resin. The resin was obtained by the standard method of polycondensation of thiourea with formaldehyde at a molar ratio of thiocarbamide:formaldehyde = 1:2. The choice of thiourea-formaldehyde resin is due to the availability, water solubility and the presence of a sufficient number of proton acceptor centers capable of complexation with a modifier. The modifier for composite materials used a coal waste product related to promising natural polymers in nanotechnology, sodium humate, extracted by alkaline extraction from oxidized coal from the Shubarkol deposit. Sodium humate refers to polyfunctional polymers with a unique combination of hydrophobic and hydrophilic sites, a variety of oxygen-containing functional groups, aromatic, heterocyclic and other groups. All this suggests a high ability of sodium humate to intermacromolecular interactions with both the burned rock and thiourea-formaldehyde resin. Composite material based on burned rock, sodium humate with thiourea-formaldehyde resin was synthesized by impregnation using ultrasonic treatment. The decisive role of ultrasonic activation is shown and the effectiveness of its application to the process of producing composites is noted. The modern physicochemical and physicomechanical methods have characterized the composition and structure of the obtained composite materials. The mineralogical composition of composite materials was studied using x-ray phase analysis, and surface morphology based on microscopic analysis using a scanning electron microscope. Filling the composite material with burnt rock provides higher physical and mechanical properties. The strength of burnt-filled composites is higher than that of samples of a similar composition without burnt rock. The resulting composite can be used as a building material. Key words: composite material, filler, binder, burned rock, thiourea-formaldehyde resin.

In the process of in situ synthesis using ultrasound, a magnetoactive sorbent based on humic acid and magnetite was produced for the extraction of heavy metals from industrial wastewater by magnetic solid-phase extraction. When exposed to ultrasound, substances are dispersed, which results in an increase in the specific surface area of the studied sorbent and the opening of inaccessible pores on its surface. Humic acid, which is part of the magnetoactive sorbent, is a stabilizer of the size of magnetite nanoparticles. The composition and sorption properties of a magnetoactive compound with respect to heavy metal ions Pb(II), Cu(II), Zn(II), Sr(II), Fe(III), and Al(III) were investigated. The dependence of the sorption value of the studied metal ions on the temperature and pH of the waste water was examined, the sorption capacity of the magnetoactive compound and the degree of waste water purification were determined. It was found that the maximum extraction of metal ions Pb(II), Cu(II), Al(III), Zn(II), Sr(II), Fe(III) from wastewater occurs at 25°C and pH 6.5, after additional sorption post-treatment, the content of Pb(II), Cu(II) and Zn(II) ions decreases by more than 15 times, and of Al(III), Pb(II), and Fe(III) ions, more than 12 times. The maximum degree of water purification from metal ions Pb(II), Cu(II), Al(III), Zn(II), Sr(II), and Fe(III) is 98.8, 83.1, 81.5, 78.1, 69.5, and 42.5%, respectively.

A nanocomposite material based on humic acid and functionalized multiwalled carbon nanotubes was obtained using ultrasonic treatment. The composition and properties of the nanocomposite were characterized. The applicability of the nanocomposite material as a sorbent for wastewater treatment was demonstrated.

Studies for developing composite materials based on coal waste in combination with coal and polymer raw materials under the influence of ultrasound have been carried out within the framework of creating effective and environmentally friendly technologies for the deep processing of coal waste and the production of new valuable import-substituting chemical products for various purposes. Burned rocks (BR) are used as a filler in the composite material that is a product of oxidative self-firing of waste rock extracted along with coal to the surface. Sodium humate (HNa) obtained by alkaline extraction from oxidized coals from the Shubarkol deposit was used as a modifier. A polymer was introduced into the matrix to increase the chemical resistance and increase the life cycle of the composite material. Polystyrene was used as a polymer in the matrix of the composite material. The choice of polystyrene is due to its widespread application in construction, medicine, and food industry as well as its ease of processing. It is distinguished by high rigidity, hardness and excellent transparency values. Composite material was obtained by the traditional method of impregnation using ultrasonic exposure. By varying the composition of the matrix and the filler, a composite material was obtained properties of which were quantitatively and qualitatively different from the properties of each of its components. The X-ray phase composition of new composite materials was studied on a DRON-2.0 diffractometer using Co(K alpha) radiation. Microscopic analysis was performed using a scanning electron microscope to study the surface morphology of the synthesized composite. The resulting composite can be used as a building material.