Some considerations of the influence of source clay material and synthesis conditions on the properties of Al-pillared clays

Pillared clays are interesting materials with applications in catalysis and adsorption processes. To obtain these materials, several preparation procedures are necessary and must be optimized to tune the final properties of the resulting pillared clay. Therefore, this article reports the influence of synthesis parameters (temperature and concentration) of Keggin-Al13 polycations and different intercalation times (0.5 up to 72 h) on the structural properties of Al-pillared clays. The natural clays are from Brazil, and they are composed mainly of montmorillonite. By XRD, N2 sorption, XRF and 27Al NMR results of the Al-PILCs, we verified that the pillaring solution could be prepared at room temperature with an aging time of 24 h. For the cation exchange process, a period of at least 2 h is necessary to ensure the formation of pillared materials. The concentration of the Keggin-Al13 polycations was evaluated by using diluted pillaring solutions followed by applying re-pillaring procedures. After submitting the pillared clay to another pillaring process, the number of pillars in the interlamellar space increased; however, the micropore volume decreased concomitantly. Thus, by optimizing the synthesis conditions of the Keggin-Al13 polycations, Al-PILCs could be obtained with good values of basal spacing and specific surface area.

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SEM study of quartz grains from recent sediments: Western Iraq

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010017743x ◽

1990 ◽

Vol 48 (4) ◽

pp. 860-861

Author(s):

F. Al-Kufaishi

Keyword(s):

Factor Loading ◽

Fault System ◽

Clay Material ◽

Crustal Material ◽

Factor Analyses ◽

Five Factors ◽

Sem Study ◽

Recent Sediments ◽

Quartz Grains ◽

Positive Factor

Two localities (Al-Marij and Laik) were selected to investigate the type of Quartz Grains from crustal material formed by evaporation of waters discharged by springs in Hit area, western Iraq, Previous studies on the crustal material (1,2) showed that the water discharged by these springs are associated with Abu-Jir fault system which run parallel to the Euphrates river,Factor analyses of the crustal and soil materials (50 samples analysed for 16 variables)(2) showed five factors; the first factor includes SiO2, Al2O3 and TiO2 with positive factor loading, and CaO, L.O.I. with negative loading and hence lead to the conclusion that the distribution of these variables is a reflection of transported clay material.This study concentrates on the use of SEM to investigate the contribution of Quartz grains found in the crustal material on two selected sites.

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Catalysts for hydrogenation of CO2 into components of motor fuels

Catalysis and petrochemistry ◽

10.15407/kataliz2020.30.001 ◽

2020 ◽

pp. 1-18

Author(s):

Yu.V. Bilokopytov ◽

◽

S.L. Melnykova ◽

N.Yu. Khimach ◽

◽

...

Keyword(s):

Carbon Dioxide ◽

Heterogeneous Catalysts ◽

Fossil Fuels ◽

Catalyst Stability ◽

Co2 Conversion ◽

Active Components ◽

Synthesis Conditions ◽

Hydrogenation Of Co2 ◽

Mesoporous Zeolites ◽

Motor Fuels

CO2 is a harmful greenhouse gas, a product of chemical emissions, the combustion of fossil fuels and car exhausts, and it is a widely available source of carbon. The review considers various ways of hydrogenation of carbon dioxide into components of motor fuels - methanol, dimethyl ether, ethanol, hydrocarbons - in the presence of heterogeneous catalysts. At each route of conversion of CO2 (into oxygenates or hydrocarbons) the first stage is the formation of CO by the reverse water gas shift (rWGS) reaction, which must be taken into account when catalysts of process are choosing. The influence of chemical nature, specific surface area, particle size and interaction between catalyst components, as well as the method of its production on the CO2 conversion processes is analyzed. It is noted that the main active components of CO2 conversion into methanol are copper atoms and ions which interact with the oxide components of the catalyst. There is a positive effect of other metals oxides additives with strong basic centers on the surface on the activity of the traditional copper-zinc-aluminum oxide catalyst for the synthesis of methanol from the synthesis gas. The most active catalysts for the synthesis of DME from CO2 and H2 are bifunctional. These catalysts contain both a methanol synthesis catalyst and a dehydrating component, such as mesoporous zeolites with acid centers of weak and medium strength, evenly distributed on the surface. The synthesis of gasoline hydrocarbons (≥ C5) is carried out through the formation of CO or CH3OH and DME as intermediates on multifunctional catalysts, which also contain zeolites. Hydrogenation of CO2 into ethanol can be considered as an alternative to the synthesis of ethanol through the hydration of ethylene. High activation energy of carbon dioxide, harsh synthesis conditions as well as high selectivity for hydrocarbons, in particular methane remains the main problems. Further increase of selectivity and efficiency of carbon dioxide hydrogenation processes involves the use of nanocatalysts taking into account the mechanism of CO2 conversion reactions, development of methods for removing excess water as a by-product from the reaction zone and increasing catalyst stability over time.

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Epoxy-titania composites of cationic polymerization: synthesis conditions and properties

Polymer journal ◽

10.15407/polymerj.37.04.402 ◽

2015 ◽

Vol 37 (4) ◽

pp. 402-407

Author(s):

S.V. Zhil’tsova ◽

◽

V.M. Mikhal’chuk ◽

N.G. Leonova ◽

R.I. Lyga ◽

...

Keyword(s):

Cationic Polymerization ◽

Synthesis Conditions

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RHEOLOGICAL PROPERTIES OF CERAMIC MASSES: IMPROVEMENT BY COMPLEX MATERIAL ACTIVATION

The Russian Automobile and Highway Industry Journal ◽

10.26518/2071-7296-2019-3-334-351 ◽

2019 ◽

Vol 16 (3) ◽

pp. 334-351

Author(s):

A. S. Mavlyanov ◽

E. K. Sardarbekova

Keyword(s):

Rheological Properties ◽

Raw Materials ◽

Sensitivity Coefficient ◽

Raw Material ◽

Clay Material ◽

Fibrous Materials ◽

Chemical Production ◽

Production Wastes ◽

Pass Through ◽

The Masses

Introduction. The objective of the research is to study the effect of the complex activation of the alumina raw material on the rheological properties of the ceramic mass. In addition, the authors investigate solutions for the application of optimal coagulation structures based on loams and ash together with plastic certificates.Materials and methods. The authors used the local forest like reserves of clay loams at the BashKarasu, ash fields of the Bishkek Central Heating Centre (BTEC) and plasticizer (sodium naphthenate obtained from alkaline chemical production wastes) as fibrous materials. Moreover, the authors defined technological properties of raw materials within standard laboratory methodology in accordance with current GOSTs.Results. The researchers tested plastic durability on variously prepared masses for the choice of optimal structures. The paper demonstrated the plastic durability of complexly activated compounds comparing with non-activated and mechanically activated compounds. The sensitivity coefficient increased the amount of clay loams by mechanically and complexly activated, which predetermined the possibility of intensifying the process of drying samples based on complexly activated masses.Discussion and conclusions. However, mechanical activation of clay material reduces the period of relaxation and increases the elasticity coefficient of ceramic masses by 1.8–3.4 times, meanwhile decreases elasticity, viscosity and the conventional power during molding, which generally worsens the molding properties of the masses. Сomplex activation of ash-clay material decreases the period of relaxation and provides an increase in elasticity, plasticity of ceramic masses by 46–47%, reduction in viscosity by 1.5–2 times, conventional power on molding by 37–122% in comparison with MA clay loams. Ceramic masses based on spacecraft alumina raw materials belong to the SMT with improved rheological properties; products based on them pass through the mouthpiece for 5–7 seconds.

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Effect of synthesis conditions on the structure and properties of new SiCxNyMz materials for spintronics

Журнал структурной химии ◽

10.26902/jsc20170803 ◽

2017 ◽

Vol 58 (8) ◽

pp. 1543-1552

Author(s):

N.I. Fainer ◽

◽

R.V. Pushkarev ◽

V.A. Shestakov ◽

A.K. Gutakovsky ◽

...

Keyword(s):

Structure And Properties ◽

Synthesis Conditions

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SOME DIRECTIONS IN THE MODIFICATION OF AZOLES

SERIES CHEMISTRY AND TECHNOLOGY ◽

10.32014/2020.2518-1491.84 ◽

2020 ◽

Vol 5 (443) ◽

pp. 85-91

Author(s):

Ibrayev M.K., ◽

◽

Takibayeva A.T., ◽

Fazylov S.D., ◽

Rakhimberlinova Zh.B., ◽

...

Keyword(s):

13C Nmr Spectroscopy ◽

Biologically Active Compounds ◽

Biologically Active ◽

Active Compounds ◽

Synthesis Conditions ◽

Alkaloid Cytisine ◽

Azole Ring ◽

Cyclic Compounds ◽

New Compounds ◽

Derivatives Of

This article presents studies on the targeted search for new derivatives of azoles, such as benzthiazole, 3,5-dimethylpyrazole, 1,3,4-oxadiazole-2-thione, 1,3,4-thiadiazole. The possibility of combining in one molecule of the azole ring with other cyclic compounds: the alkaloid cytisine, morpholine, furan and some arenes has been studied. To obtain new compounds, the reactions of bromination, acylation, and interaction with isothiocyanates were studied. Optimal synthesis conditions were studied for all reactions. It was found that the reaction of 4-bromo-3,5-dimethylpyrazole with isothiocyanates, in contrast to the previously written derivatives of anilines, takes a longer time and requires heating the reaction mixture. The combination of a pirasol fragment with halide substituents often results in an enhanced therapeutic effect. The synthesized 2-bromine-N-(6-rodanbenzo[d]thiazole-2-yl)acetamide, due to the alkylbromide group, is an important synth in the synthesis of new benzthiazole derivatives. Its derivatives combine in one molecule the rest of rhodanbenzthiazole with alkaloid cytisine and biogenic amine morpholine and are potentially biologically active compounds, since the molecule structure contains several pharmacophoric fragments: benzthiazole and alkaloid (amine) heterocycles, rhodane and urea groups. The mechanism of formation of 1,3,4-oxadiazole-2-tyons from hydrazides under action on them by carbon disulfide was studied and assumed. It was shown that dithiocarbamates in acidic medium decompose with the release of hydrogen sulfide and the formation of highly reactive isothiocyanate group. Then, intra-molecular cyclization occurs, with the formation of end products - 1,3,4-oxadiazole-2-thions. The structures of the synthesized compounds were studied by 1H and 13C NMR spectroscopy. All synthesized substances are potentially biologically active compounds, since they contain several pharmacophore fragments in their structure.

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