The solvent extraction of some rare earth metals (REM) from chloride and nitrate solutions by binary extractants, such as salts of trioctylmethylammonium with dialkylphosphinic, ...dialkylmonothiophosphinic, dialkyldithiophosphinic acids in toluene, as a function of the compositions of the aqueous and organic phases has been studied. The extraction isotherms of rare earth metals in trioctylmethylammonium bis(2,4,4-trimethylpentyl)phosphinate system were examined. The effect of binary extractant concentration in the organic phase and concentration of salt present in the aqueous phase (NaCl, NaNO
3) was also investigated. The ratio of
C
ex:
C
Ln(org) was found for REM chlorides close to 3, whereas that was found for REM nitrates close to 1 in the case of the loaded organic phase. Extraction efficiency of binary extractants towards lanthanum chloride as well as lanthanum nitrate decreases in the series: dialkylphosphinate
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dialkylmonothiophosphinate
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dialkyldithiophosphinate of quaternary ammonium base (QAB). The separation factors of some metal pairs in the extraction of chlorides and nitrates of lanthanides were calculated using the experimental data obtained. Effective extraction systems involving binary extractants for separation of rare earth metals from chloride and nitrate solutions were found.
Based on the example of an automated module of a vertical farm for growing plants, an author’s method for developing automated devices using modern microcontrollers and a high-level microPython ...programming language is proposed. Additive technology as a method of “rapid prototyping” made it possible to effectively solve the issue of creating the main components of the module. The works on designing, assembling, and adjusting the experimental setup were carried out using modern methods and approaches for the industrial development of devices. The automated system makes it possible to solve the problems of lack and selection of the correct dosage of nutrients necessary for plants, controls, and minimizes water consumption, the root system develops fully. These factors make it possible to grow an adult plant in a short time without human participation. The apparatus can be used for organizing research activities in the subject areas of the natural science cycle, for greening in corridors and classrooms, and growing fresh herbs.
A theory of bulk-supported liquid membrane extraction has been developed. The process is performed sequentially in a series of three-phase mass-transfer stages. In each stage the extractant ...circulates in a closed circuit and alternately contacts a donor (feed) phase and an acceptor (stripping) phase. Special cases have been analyzed in which the phases in the chambers move countercurrently in plug-flow mode; contact chambers represent perfectly-mixed cells; contact chambers consist of a series of theoretical stages; each contact chamber represents a theoretical stage. Experimental and computational studies on extraction and separation of lanthanide chlorides have been carried out using two schemes of a cascade of mixer-settlers: (1) connected in the usual way with external circulation of the extractant (the extractant first passes through all the stages of extraction and then through all the stripping stages) and (2) based on a bulk-supported liquid membrane (the extractant recycles between each pair of extraction and stripping stages). The effectiveness of the bulk-supported liquid membrane extraction scheme was considerably greater than that of the conventional scheme. Experiments on the extraction of lanthanide chlorides from neutral aqueous solutions in the system involving methyltrioctylammonium di(2-ethylhexyl)phosphate were carried out. The experimental results are in satisfactory agreement with the data calculated, which confirms the agreement between theory and experiment. The bulk-supported liquid membrane extraction can be applied to other systems and heavy metals as well.
•A theory of the bulk-supported liquid membrane technique has been developed.•The degree of extraction and separation of metals increases when using this technique.•The experimental results are in a satisfactory agreement with the calculated data.
For purposes of providing bacterial control, door handles and other contact surfaces are sometimes made of copper, which has antibacterial properties but is high in cost and has poor mechanical ...properties. In the work, a complex copper–titanium oxide is studied to search for new antibacterial materials and coatings. A low-cost solution method to obtain complex oxides is proposed, which will allow the deposition of oxide films on large and complex surfaces. The influence of the ratio of the components in the Cu–Ti–O complex oxide on the antibacterial activity of films is studied.
The mechanisms of the extraction of rare earth metals from nitrate media with the binary extractant—methyltrioctylammonium di(2,4,4-trimethylpentyl)phosphinate with the formation of extracted species ...of different composition in the organic phase have been suggested. Compositions of the extracted species which distribution is satisfactorily described by the calculated curves have been determined. The calculated concentration values obtained by using the proposed equations were found to be in a good agreement with the experimentally obtained values for lanthanum and ytterbium extraction with the binary extractant from nitrate solutions.
► We suggest mechanisms of the binary extraction of rare earth metals from nitrate media. ► Increase in NO3− aqueous concentration promotes the extraction of lanthanides. ► The calculated La and Yb isotherms satisfactorily describe the experimental data.
The possibility of creating capacitor structures based on porous silicon with oxide ferroelectrics embedded in the pores—barium strontium titanates, which have a diffuse phase transition—is ...considered. In this case, thin films of barium strontium titanate are characterized as nanostructures with ferroelectric properties. To obtain such structures, the extraction-pyrolytic method is used. The dependences of the capacitance and permittivity of the structures on the ratio of barium and strontium components in barium strontium titanates are studied. The results of this work confirm the possibility of using the presented technologies—the production of porous silicon matrices and the extraction-pyrolytic method for producing a ferroelectric based on barium and strontium titanates—to create a capacitive-type structures with different dielectric characteristics due to the possibility of varying the obtained ferroelectric composition, dimension, and morphology of the porous silicon matrix.
The review presents a summary of the application of the extraction-pyrolytic method for preparing inorganic materials. For 25 years, since the first publication, this method has received wide ...acceptance in studies on obtaining functional materials for various purposes. The main advantages of the extraction-pyrolytic method and its advantages compared to traditional methods have been considered. This paper contains materials reported at the Russian symposium “Extraction and Sorption Processes in Technology and Analytics,” Moscow, December 17, 2014.
A short review of the literature data on extraction with hydrophobic bifunctionalized ionic liquids and binary extractants is given to show that these compounds are identical in their compositions ...and properties. It is noted that the papers on binary extractants were published earlier than the first papers on extraction with bifunctionalized ionic liquids. In contrast to the extraction systems with ionic liquids, extraction processes in the systems with binary extractants are studied in greater detail and grouped into a special class, i.e., binary extraction. It is shown that the main regularities of the distribution of the components in the extraction systems with binary extractants depend on the type of chemical reaction and the character of the interphase distribution.
This paper reports studies of thin films of nickel oxide obtained by the extraction–pyrolysis method on glass and quartz substrates at temperatures of 380–600°C. The films have been characterized by ...atomic force microscopy and X-ray diffraction. It is shown that amorphous and crystalline nickel oxide films are formed on the glass. The grain size depends on the annealing temperature, while increased annealing temperatures lead to recrystallization and a decrease in the grain size in NiO films from 130 to 35 nm.
Iron lithium phosphorus oxide, which is promising for use as a cathode material in lithium-ion batteries, has been synthesized by the extraction-pyrolytic method and further investigated. The ...possibility of obtaining phosphorus-containing Li–Fe–P–O cathode materials using di-(2-ethylhexyl)phosphoric acid has been shown. Structural and optical studies of Li–Fe–P–O dispersed material have been carried out using X-ray photoelectron spectroscopy and X-ray diffraction. The conditions for the formation of crystalline phases of these dispersed materials have been established. It has been shown using spectroscopic methods that the material contains carbon in its composition, which helps improve electron mobility.
