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 search for new effective drugs with biologically active properties is one of the urgent problems. Recently, to intensify the process of their synthesis and increase the efficiency of chemical reactions, wave chemistry has been used. Increased interest of researchers is caused by the synthesis of compounds with biologically active properties using the method of ultrasonic treatment (US). It is known that derivatives of p-aminobenzoic acid and their esters are synthetic analogues of natural compounds, and pyrrolidone derivatives have high hypnotic, anticonvulsant, antiarrhythmic activity, which stimulates the synthesis of new biologically active compounds. In a brief report, the possibility of synthesizing ethyl-4-(2,5-dioxo-2,5-dihydro-1H-pyrrolyl) benzoate from 3-[(4-ethoxycarbonyl) phenylcarbamoyl]-2-propenoic acid using ultrasonic activation through a step is considered disclosure of the furan cycle with further cyclization. Ethyl ester p-aminobenzoic acid and maleic anhydride were used as starting reagents. An ultrasound device IL-100-6/2, equipped with a magnetostrictive transducer, with an operating frequency of 22 kHz, with a maximum power of 1200 W and a cylindrical waveguide, was used as a source of ultrasound. The synthesis of 3-[(4-ethoxycarbonyl) phenylcarbamoyl]-2-propenoic acid was carried out by reacting the starting reagents at equimolar ratios and room temperature. The US time was 10 minutes. The reaction proceeds smoothly. Ultrasound has a significant effect on the rate of chemical reactions and can increase the yield of the final product. Under classical conditions, the synthesis time was 180 minutes; using ultrasound, the synthesis time was reduced by 3 times. The product yield was 92%. The structure and composition of the obtained compound was confirmed by IR- and H1 NMR-spectroscopy. In the IR-spectra of the obtained compound, there are absorption bands of the amide group (NHCO) in the region of 3280, 3190 cm-1, absorption bands of the carbonyl group (C=O), characteristic in the region of 1670 cm-1, absorption band (COC) in the region of 1230 cm-1. The resulting compound, 3-[(4-Ethoxycarbonyl) phenylcarbamoyl]-2-propenoic acid, made it possible to study the step of opening the furan ring, with further cyclization. Ethyl 4-(2,5-dioxo-2,5-dihydro-1H-pyrrolyl) benzoate was obtained in 89% yield by azeotropic distillation of water in the presence of toluenesulfonic acid in a DMFA-toluene mixture. The resulting product is a light yellow powder with melting point 114-115°C. The structure and composition of the obtained compound was confirmed by IR-and H1 NMR-spectroscopy. In the IR-spectra of the obtained compound, the stretching vibrations of the НС=СН group manifest themselves in the form of a low-intensity but characteristic signal at 3100-3090 cm-1, stretching vibrations of the С=О group as intense bands in the region of 1700-1680 cm-1 and a weak overtone at 3465-3450 cm-1, stretching vibrations of the COC group in the region of 1245 cm-1. When analyzing the Н1 NMR-spectrum of a compound, ethyl 4-(2,5-dioxo-2,5-dihydro-1Н-pyrrolyl) benzoate, the signals of aromatic four protons Н1- Н2 (4Нaryl, 3JНН 8 Hz) are recorded in the field of weak fields: H1 doublet at 7.51 ppm. and a doublet at 8.05 ppm. Signals of the ethyl fragment: (3H, CH3, 3JHH 8 Hz), appear as a singlet at 1.43 ppm. and (2H, CH2, 3JHH 8 Hz) quadruplet at 4.34 ppm. The protons of the CH group of the imide cycle (2H, CH=CH) appear as a singlet at 7.11 ppm. Keywords: ultrasound, ethyl ether p-aminobenzoic acid, maleic anhydride, cyclization.

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.

The summary report considers the possibility of synthesis of copper nanoparticles by precipitation in aqueous media. Copper nanoparticles obtained by the method of chemical reduction of ions from solution under action of reducing agent - sodium borohydride have been studied, and also provided for strengthening stabilization of nanoparticles by introduction of modifying additive - polyoxyethylene sorbitan monooleate (Tween 80), which effectively interfere with aggregation of nanoparticles in solution. The size and properties of the copper nanoparticles dispersions were investigated in various ways. The size of the nanoparticles and their degree of aggregation were examined using a Malvern Zetasizer Nano (UK) size analyzer. UV and visible absorption spectra were obtained on a two-beam scanning spectrophotometric UV-1800 (Japan). In the synthesis of nanoparticles by precipitation in aqueous media, quite large particles (up to a few micrometers) are formed, which aggregate and precipitate. Additives of various surfactants are often used to slow growth and form nanometer-sized particles. Nucleation of copper in aqueous media occurs almost instantaneously after mixing of the reactants. However, further particle growth, aggregation, and growth take longer. The stabilizing ability of the nanoparticles is enhanced by the introduction of surfactants. The effect of the concentration of these components for determining compositions resistant to sedimentation of copper nanoparticles dispersions has also been investigated. During the first minute of synthesis, most of the copper nanoparticles are formed. When the system is further held, the optical density increases, but to a lesser extent. When the synthesis process is carried out for more than 20 minutes, the absorption spectra are practically unchanged. This indicates the establishment of quasi-equilibrium in the system. In the system, at a high concentration of nanoparticles, aggregation of the aggregates and their subsequent sedimentation may occur. The effect of the concentration of these components for determining compositions resistant to sedimentation of copper nanoparticles dispersions has also been investigated. The greater the concentration of copper ions in the feed solution, the greater the amount of crystallization nuclei formed by adding a reducing agent to the solution. However, at a high concentration, uncontrolled growth of nanoparticles can occur, resulting in a dispersion of sufficiently large particles with a wide size distribution that are unstable to aggregation and sedimentation.

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.

In the article authors provide the results of tuberculostatic activity research of the following chemical compounds: N-3-(2-(2-hydroxybenzoyl) hydrazinyl)-3-(oxopropyl)-isonicotinehydrazide and 3-(2-(2-hydroxybenzoyl)- hydrazinyl)-propionyl-(morpholine-4)-dithiocarbamate as related to strains: M. bovis-8 (reference strain), M. bovis (epizootic strain) and M. scrofulaceum, M. phlei (atypical strains).

2-(2-hydroxibenzoyl)-S-3-(piperidine-1-yl)-propionilhydrazinoditiocarbamate was synthesized by the interaction of S-akriloyl-2-(2-hydroxibenzoyl)-hydrazinoditiocarbamino acid with piperidine. Also N-(2-(2hydroxibenzoil)- hydrazino-1carbonothionyl-methacrylamide was synthesized by the interaction of hydrazide of salicylic acid with methacryloilisothiocyanate. It was revealed that the synthesized compounds exhibit tuberculostatic activity to epizootic bovine strains of M. tuberculosis.

For the first time polymeric complexes of gumic and nitrogumic acids with jelatine were obtained. Influence of structure of an initial mix on theacid- alkaline and sorptional properties of the obtained complexes was investigated and increase of these properties under the influence of gelatinous gel was noted. The big efficiency nitrogumic complexes in sorptional processes of water treating from ions of metals in comparison with gumic was shown.

This article has results of studding on dependence of process to activation. fosfat natrium and aminogumin acid. Also, it has results of studded of process of sorption ionic of heave metals on modified surfaces breeds. It has been given comporative estimation of sorbtion proporties of natural and modified kind surfacis containing breeds.

By reaction of 2-vinyloxyethyl isothiocyanate with salicylic acid hydrazide a synthesis of the corresponding thiosemicarbazide was performed. Alkaline hydrolysis of the latter led to an intramolecular heterocyclization into 1,2,4-triazole derivative. When cyclization was carried out in the water-alkali medium, 2-vinyloxyethyl fragment was shown to be hydrolyzed to form 4-(2-hydroxyethyl)-5-(2-hydroxyphenyl)-2 H -1,2,4-triazolo-3(4 H )-thione, whose spatial structure was established by XRD analysis.

Certain derivatives of ethyl p -aminobenzoate were synthesized with the purpose of creating biologically active oligomeric condensation products.