Pages Navigation Menu
Submit scientific paper, scientific publications, International Research Journal | Meždunarodnyj naučno-issledovatel’skij žurnal

CHEMISTRY

ISSN 2227-6017 (ONLINE), ISSN 2303-9868 (PRINT), DOI: 10.18454/IRJ.2227-6017
ПИ № ФС 77 - 51217, 16+

PHASE FORMATION IN MECHANOCHEMICAL SYNTHESIS OF EUROPIUM AND LANTHANUM HAFNATES: AB INITIO MODELING AND EXPERIMENTAL STUDY

Posted in 2020, CHEMISTRY, Issue № 01(91) January 2020 | 0 comments

The phase diagrams for La-Hf-O and Eu-Hf-O systems at 0K were constructed with the help of the first-principle modeling method. One of the main differences between these systems is the existence of a nonequilibrium La2HfO5 phase in the La-Hf-O system. Equimolar mixtures of La2O3 + HfO2 и Eu2O3 + HfO2 oxides were subjected to mechanochemical treatment for 45 min. The structure and phase composition of the products of mechanosynthesis were investigated. The authors formulated mechanisms of phase transformations during the mechanochemical treatment La2O3 + HfO2 и Eu2O3 + HfO2 mixtures. The formation of the non-equilibrium La2HfO5 phase during mechanochemical treatment and a significantly higher degree of conversion of the starting reagents to the stable La2Hf2O7 phase were detected for the Eu2O3 + HfO2 mixture, while the Eu2O3 + HfO2 mixture was characterized by selective amorphization of europium oxide, structural transformations of hafnium oxide from monoclinic orthorhombic, and relatively low conversion to the Eu2Hf2O7 phase.

Read More

PATTERN FORMATION ON SURFACE OF HIGH-DENSITY POLYETHYLENE

Posted in 2019, CHEMISTRY, Issue № 12(90) December 2019 | 0 comments

The authors obtained nanocomposite materials in the form of a flexible polymer substrate with a hard coating as a result of plasma treatment of high-density polyethylene (HDPE) films and metal (gold) deposition on the surface of HDPE films. Fragmentation of the hard coating takes place with the formation of a unique ordered relief on the polymer surface during deformation of the obtained materials. Using scanning electron microscopy, the parameters of the obtained relief are determined depending on the drawing conditions and subsequent shrinkage of the deformed nanocomposites. The proposed approach may be applied as a method of modifying the surface properties of polymers.

Read More

METHODOLOGICAL FEATURES OF DETERMINATION OF DIPYRIDYL SALTS IN AGRICULTURE AND PLANT PRODUCTS

Posted in 2019, CHEMISTRY, Issue № 12(90) December 2019 | 0 comments

The paper presents methodological features of methods for determining the residual amounts of dipyridyl salts (on the example of dibromide diquat) in potatoes, peas, rapeseeds, soybeans and vegetable oils using ion-pair high-performance liquid chromatography (HPLC) with an ultraviolet detector after extracting a substance from an analyzed sample with diluted sulfuric acid upon boiling, purification of the extract, and concentration of the substance by ion-exchange chromatography on a column with Dowex 50Wx8 cation exchange resin, as well as additional purification on pat solid-phase C18 Sep Pak extraction. The authors reached the lower limits for the quantitative determination of diquat in potato tubers — 0.025 mg/kg, soybean, rape, sunflower, pea — 0.05 mg/kg, vegetable oils — 0.05 mg/kg.

Read More

CHEMICAL MODIFICATION OF AMINOPOLYSACCHARIDE FROM SHRIMP SHELL BY DIRECT GRAFTING WITH POLYANILINE

Posted in 2019, CHEMISTRY, Issue № 12(90) December 2019 | 0 comments

Aminopolysaccharide was modified by deacetylation of chitin from shrimp shell using enzyme as a biocatalyst and microwave energy. Modified aminopolysaccharide has degree of deacetylation of 83 higher than that of using normal chemical method. Aminopolysaccharide was successfully grafted with aniline by free radical mechanism with ammonium persulfate initiator. The reaction was carried out in aqueous medium. The effect of reaction temperature, reaction time, aminopolysaccharide: aniline weight ratio were investigated. The results showed that the best conditions for grafting of aminopolysaccharide were aminopolysaccharide: aniline weight ratio of 1:2, reaction temperature of 5oC and reaction time of 60 minutes. The modified aminopolysaccharide was characterized by Fourier transform infrared spectroscopy and Scanning electron microscopy. Degree of Grafting of modified aminopolysaccharide obtained 41%.

Read More

SYNTHESIS AND CRYSTAL CHARACTERIZATION OF PALLADIUM(II) NITRATE COMPLEXES

Posted in 2014, CHEMISTRY, Issue April 2014 | 0 comments

In the article considered the synthesis and structure of mononuclear cis-diamine complexes of palladium (II), which easly undergoes to process of hydrolysis – [Pd(tmen)(NO3)2] and [Pd(2-ampy)(NO3)2] (where tmen – N,N,N`,N` – tetramethylethylenediamine, 2-ampy – 2-aminomethylpyridine). Data of the X-ray structural analysis also provided. Relative catalytic activity of complexes is considered in reaction of oxidation biothiols.

Read More

ADVANCED POLYMER COMPOSITES FOR FILLERS

Posted in 2014, CHEMISTRY, Issue April 2014 | 0 comments

In this paper we describe the use of polyhedral oligomeric silsesquioxanes for the synthesis of radiation-resistant polymer composites

Read More

HETEROANALOGS OF PROSTAGLANDINENDOPEROXIDE ON THE BASIS OF STEREOISOMER 3,4,5,6-TETRACHLORTRICYCLO[6.2.1.02,7]-UNDEKA-3,5-DIEN-9,10-DICARBOXYLIC ACIDS

Posted in 2014, CHEMISTRY, Issue April 2014 | 0 comments

Heteroanalogs of prostaglandinendoperoxide have been synthesized on the basis of adducts of reaction of 5,5-dimethoxytetrachlorcyclopentadiene with stereoisomer endo- and exo-bicyclo[2.2.1]hept-5-en-2,3-cis-(trans-)acids.

Read More

STABILITY OF THE Pt-Ru CATALYSTS IN SELECTIVE OXIDATION OF METHANE INTO SYNTHESIS-GAS

Posted in 2014, CHEMISTRY, Issue April 2014 | 0 comments

The results of stability studies of optimal particulate developed Pt-Ru = 1: 1 (Pt: Ru = 0,7: 0,3, at.%) Of the catalyst in the reaction SCO (selective catalytic oxidation) and steam-oxygen conversion of methane to synthesis gas at millisecond contact times.

Read More

THERMAL STABILITY STUDY OF DRUGS OBTAINED BASED ON INTERACTION OF CIS-DICHLORODIAMMINPLATIN (II) and CIS-DIAMINE (CYCLOBUTANE-1,1-DICARBOXYLATE-O, O`) II PLATINUM (II) WITH ARABINOGALACTAN AND THEIR MIXTURES

Posted in 2019, CHEMISTRY, Issue № 11(89) November 2019 | 0 comments

New preparations based on the interaction of cis-dichlorodiammineplatin (II) salt and cis-diamine (cyclobutane-1,1-dicarboxylate-O, O`) platinum (II) salt with arabinogalactan are studied in the paper. It is established that during thermal decomposition of new drugs and their mechanical mixtures, the catalytic effect of platinum complexes during the oxidation of CO in CO2 is the cause of the increase in thermal effects, compared with arabinogalactan. It is shown that the preparations are products containing complex compounds of platinum and arabinogalactan.

Read More

SORPTION OF ORGANIC AND MINERAL DIFFUSANTS BY POLYPHENYLENE SULFIDE

Posted in 2019, CHEMISTRY, Issue № 11(89) November 2019 | 0 comments

The sorption of organic solvents and inorganic acids by polyphenylene sulfide granules is studied in the paper. It is shown that quasi-equilibrium sorption values can be achieved within 1 … 14 days of exposure at a temperature of 23°C. The studied diffusants can act as effective carriers for introducing additives and activators for various purposes into polyphenylene sulfide.

Read More

EVOLUTION OF Fe-Pd SOLID SOLUTION COMPOSITION IN ONE-STEP METAL-CARBON NANOCOMPOSITE FABRICATION METHOD

Posted in 2019, CHEMISTRY, Issue № 10(88) October 2019 | 0 comments

The one-step procedure of simultaneous preparation of polyacrylonitrile-based carbon support and Fe-Pd bimetallic nanoparticles was proposed. The effect of synthesis conditions on the metal-carbon nanocomposite structural characteristics was shown. It was found that the crystallite size of the metallic rounded shape nanoparticles immobilized in the carbonized polymer matrix increases as synthesis temperature rises. The lattice constant of a solid solution based on fcc-Pd in the nanocomposite is smaller than that characteristic of bulk fcc-Pd and decreases with increasing synthesis temperature.

Read More

INVESTIGATION OF THE STRUCTURE OF ASPHALTENES SPECTRAL METODS

Posted in 2014, CHEMISTRY, Issue March 2014 | 0 comments

IR-spectroscopy studied structural fragments of asphaltenes isolated from petroleum Gerasimovsky, Askarovsky and West Salym fields. Laser diffractometry method defined particle sizes of asphaltenes. Found that asphaltenes Askarovsky oil are more highly condensed.

Read More

SYNTHESIS OF DECAHYDROACRIDINION DIOXIME

Posted in 2019, CHEMISTRY, Issue № 5(83) May 2019 | 0 comments

The work considers the reactions of oximatization of 9- (3,5-di-tret-butyl-4-hydroxyphenyl)-3,3,6,6-tetramethyl-3,4,6,7,9,10-hexahydroacridine-1,8(2H, 5H)-dione. It was found that the attack of nucleophilic reagents on carbonyl groups into hexahydroacridin-1,8(2H, 5H)-diones proceeds with preservation of the 1,4-dihydropyridine fragment and the formation of mono- and disubstituted derivatives. The structure of the starting 9- (3,5-di-tret-butyl-4-hydroxyphenyl) -3,3,6,6-tetramethyl-3,4,6,7,9,10-hexahydro-acridine-1,8 (2H, 5H)-dione and its dioxime confirmed by 1H NMR spectroscopy.

Read More

SCIENTIFIC AND PRACTICAL ACTIVITY OF L.E. OLIFSON IN THE YEARS OF THE GREAT PATRIOTIC WAR

Posted in 2019, CHEMISTRY, Issue №4(82) April 2019 | 0 comments

The scientific and practical activities of the Honored Scientist of the RSFSR, PhD in Biology, Professor L.Ye. Olifson, aimed at helping the front and rear area during the Great Patriotic War is presented in the article. His initial research on the release of previously unknown toxic substances which are the cause of alimentary-toxic aleukia is analyzed and their structure is established. The contribution of a scientist in the field of mycotoxin chemistry is described. His role in solving the problem of alimentary-toxic aleukia is shown.

Read More

PVC COMPOSITIONS AND THEIR APPLICATION

Posted in 2019, CHEMISTRY, Issue №2(80) February 2019 | 0 comments

Polyvinyl chloride compositions are intermediates for the production of various types of products. Depending on their composition, they are divided into soft and hard ones. PVC compositions always contain heat stabilizers and lubricants, as well as impact modifiers, which are designed to absorb impact energy of plastic deformation. They are most widely used in the manufacture of hoses, furniture and tiles. The aim of the work is to analyze PVC compositions and their application.

Read More

AERODYNAMIC EXTRACTION OF ALUMINOSILICATE DISPERSED NARROW FRACTIONS FROM FLY ASH OF EKIBASTUZ COAL AND THEIR CHARACTERISTICS

Posted in 2018, CHEMISTRY, Issue №12(78) December 2018 | 0 comments

A nonmagnetic narrow fraction of dispersed particles with an average diameter of 2, 3, 6 and 10 microns from the fly ash was isolated from dust-like combustion of Ekibastuz coal by the method of aerodynamic classification followed by magnetic separation. It is established that with an increase in the size of fractions the bulk density monotonously increases from 0.90 to 1.07 g/cm3. The main components of the chemical composition of the dispersed narrow fractions are SiO2 – 65-70 wt. % and Al2O3 – 23-28 wt. %. The phase composition includes 64-69 wt. % glass phase, 17-21 wt. % phase of mullite, 10-18 wt. % of quartz. The particle size distributions are characterized by the following values d50 – 1.9; 2.3; 5.1; 9.2 microns and d90 – 4.5; 5.7; 11.4 and 16.7 microns, respectively. The main morphological types of particles are microspheres with a non-porous smooth surface and microspheres with a porous shell; as the size of fractions increases, the amount of microspheres with a porous shell increases.

Read More

STUDY OF DIFFERENT SYSTEMS APPLICATION FOR SUNFLOWER OIL OXIDATION

Posted in 2018, CHEMISTRY, Issue №12(78) December 2018 | 0 comments

The article contains data on the composition of waste of oil extraction production. The process of oxidation and polymerization of sunflower oil is considered. A series of experiments of the oxidation process in a chemical reactor is carried out. The products of the research allow obtaining composite materials for various purposes, surfactants, emulsifiers, emollients and lubricants from hazardous waste oil extraction production.

Read More

STERIC ASPECT IN THREE-STAGE SYNTHESIS OF SEX PHEROMONE OF HOUSEFLY (MUSCA DOMESTICA L.) CIS-9-TRICOZENE

Posted in 2018, CHEMISTRY, Issue №12(78) December 2018 | 0 comments

The housefly Musca domestica L is a synanthropic insect and is very dangerous to human health and pets. Sex pheromones of insects are actively used to develop and create effective means of protection. The article studies non-trivial approaches of fine organic synthesis, which allows reducing the number of stages in the preparation of pheromones. A three-stage approach to the synthesis of cis-9-tricozenes, the sex pheromone of the housefly Musca domestica L, was tested [1, P. 2792]. Synthesis of (quinolin-8-yl) -cis-9-octadecenoate is carried out and its physicochemical properties are studied. The analysis of steric hindrances in the preparation of ketones from esters and Grignard reagents was conducted.

Read More

SYNTHESIS AND RESEARCH OF HETEROGENEOUS CATALYSTS BASED ON TETRASULPHOPHTHALOCYANINE COBALT AND MODIFIED MONTMORILLONITE

Posted in 2018, CHEMISTRY, Issue №11(77) November 2018 | 0 comments

The article studies the adsorption of tetrasulfophthalocyanine cobalt (TSFC) from aqueous solutions on the natural (in the Na form) and modified by aluminum hydroxo complexes [Al13O4 (OH) 24 (H2O) 12] 7+ montmorillonite (Na-M and Al-M, respectively). It is established that the magnitude and nature of adsorption depend on the nature of the carrier. On Na-M, adsorption of TSFC is reversible, while 0.7 mg of TSFC/g Al-M adsorbs irreversibly. It is shown that irreversibly adsorbed TSFC is fixed on the surface of Al-M in monomeric form using diffuse reflectance spectroscopy. It was established that the solid fixing of TSFC on Al-M does not lead to a decrease in its activity in the oxidation reaction of a solution of sodium sulfide with oxygen: TSFC fixed in monomeric form on the carrier in the solution in the form of monomers have the same activity.

Read More

USAGE OF SOLID-PHASE EXTRACTION METHOD FOR PURIFICATION OF 16-α[18F]FLUORINE-17β-ESTRADIOL, A RADIOTRACER FOR PET DIAGNOSTICS OF BREAST CANCER

Posted in 2018, CHEMISTRY, Issue №6(72) June 2018 | 0 comments

A new method of solid-phase extraction (SPE) for the purification of 16α-[18F]fluorine-17β-estradiol ([18F]FES), radiopharmaceutical (RPC) for PET diagnostics of estrogen-positive (ER +) breast cancer is proposed. [18F]FES was obtained by nucleophilic radiofluorination of the cyclic sulfanyl precursor MMSE with subsequent deprotection by hydrolysis in an acidic medium. In order to separate [18F]FES from the reaction mixture by SPE method, disposable cartridges based on various sorbents have been studied. It was shown that the use of the OASIS WAX 3cc cartridge is the most effective and allows to obtain [18F]FES with radiochemical purity > 99% and the residual content of MMSE and chemical impurities of 2-5 μg/ml, which allows using this RPC in preclinical and clinical studies. The content of ethanol in the injection form of the drug is 5%, which meets the requirements of the State Pharmacopoeia. The advantage of the new cleaning method is simplicity, speed (40 min) and the possibility of automation in modern synthesis modules. The use of disposable SPE cartridges at the purification stage meets modern GMP requirements.

Read More