Methods of obtaining strong anion exchangers provided with oxygen-containing functional groups (–OH, C–O–C), along with pyridinium cations, were described. Spontaneous polymerization of monomeric 4-vinylpyridine under its alkylation with polyfunctional epoxides, epichlorohydrin and bis-glycidyl ethers, in a polymer solvating medium was used. The sorbents obtained are effective in the analysis of mixtures of complex noble metal ions and their sorption from multicomponent solutions in mineral acids.

Министерство науки и высшего образования Российской Федерации Российская академия наук Научный совет по неорганической химии РАН Научный совет по аналитической химии РАН Научный совет по химической технологии РАН Российское химическое общество имени Д.И

In this paper, we analyze the contrast of images obtained by scanning electron microscopy (SEM) in the backscattered electron mode, which shows that the contrast on the polished surface of multicrystalline silicon (multisilicon) is due to the parameters of misorientation between grains. The contrast values corresponding to special oblique boundaries with various inverse density values of the coinciding nodes of the crystal lattices of neighboring grains forming these boundaries are established. Since the SEM method allows relatively large surface areas of the samples (~1 cm2) to be studied, on account of the method proposed here for identifying special oblique boundaries, it is possible to analyze the nature of the interaction of boundaries and their distribution density in the structure, depending on certain crystallization conditions. In SEM studies of multisilicon, this can be important for initial analysis of the structure and further formulation of research problems without the use of special selective etchants that destroy the surface of the studied samples.

Strongly basic anion exchangers are synthesized by the spontaneous polymerization of 4-vinylpyridine under its interaction with alkyl dibromides. It is demonstrated that they can be successfully applied in the extraction of noble metal chloro complexes from acidic aqueous solutions and in the addition of СО2 to epoxides.

Министерство науки и высшего образования Российской Федерации Российская академия наук Научный совет по неорганической химии РАН Научный совет по аналитической химии РАН Научный совет по химической технологии РАН Российское химическое общество имени Д.И

The geometric parameters of the grain boundaries that make up triple joints and their possible combinations are studied by electron backscatter diffraction using Channel HKL5 software. It is shown experimentally that, in addition to the previously studied and fairly widespread triple joints of special grain boundaries, there are other varieties of them. It is found that at these triple junctions, in particular, the geometric combination rule is violated, which may indirectly indicate the recombination activity of special boundaries.

The orientation of grains and the special boundaries formed by them in multicrystalline silicon has been studied by electron backscattered diffraction. It is found that the crystallographic parameters of special boundaries (misorientation angle and rotation axis) obtained using the Tango HKL Channel 5 software module may differ from the results of their direct computation by calculating the rotation matrix in the Spyder integrated development environment, using identical formulas based on Euler angles. In particular, special boundaries ∑3, ∑9, and ∑27a with misorientation angles of 180°, 120°, and 165°, respectively, are found in multicrystalline silicon. These versions of special grain boundaries are theoretically possible for the crystals of cubic system; however, they have not been investigated experimentally in multicrystalline silicon.

Более полувека назад мы синтезировали полимер, свойства которого противоречили общепринятым канонам полимерной химии, — сверхсшитый полистирол. Несмотря на жесткую сшивку каждого звена цепи со звеньями соседних цепей, он оказался достаточно эластичным, поглощал большие количества любой жидкости, при этом заметно увеличиваясь в размерах. Сейчас сверхсшитые полистирольные сорбенты производятся тысячами тонн в год, так как нашли множество областей применения в науке и технике. Удивительным свойством жесткой ажурной сетки полимера оказалась ее полная инертность по отношению к клеткам крови и крупным белковым молекулам. Это позволило создать на базе сверхсшитых полимеров универсальные гемосорбенты, которые уже спасли сотни обреченных пациентов с общим заражением крови (сепсисом). В статье рассказывается об этапах создания этих сорбентов, оказавшихся столь востребованными в эпоху текущей пандемии короновируса.

A simple technique for introducing iron hydroxide into a highly porous polystyrene matrix is proposed. The resulting composite sorbent showed a high ability to purify air by removing hydrogen sulfide, bad-smelling, and toxic products of decay of natural remains, such as putres-cine, cadaverine, indole, and skatol, as well as organic solvents, such as methanol and benzene.

Novel hydrophilic ionic polymer nanoparticles based on the N-alkylated hypercrosslinked poly-4-vinylpyridine (nanosponges ‒ NS ) have porous structure, pH-independent positive charge and contain the aromatic rings. These nanosponges have not yet been studied in the capillary electrophoresis mode, but their characteristics suggest the possibility of creating the fused silica capillary walls coating for the separation of anionic and cationic analytes. In the current research, the authors, for the first time, have proposed the approaches to the formation of coatings based on the nanosponges with a molecular weight of 400 and 10 kDa. It was established that the stability of such coatings could be achieved by the introduction of NS into the background electrolyte. The pH range of background electrolytes for the subsequent electrophoretic experiments was determined to be from 4 to 9. The NS-based coatings were compared with the previously investigated coatings based on the crosslinked polystyrene nanoparticles ( NPs ), functionalized with the quaternary ammonium groups. Capillaries modified with NS (400 kDa) were tested for the electrophoretic separations of wide range of analytes: carboxylic acids, aminoacids, fluoroquinoline antibiotics, biogenic amines, and proteins. The separation selectivity of carboxylic acids on the NS-modified capillaries was different from the separation selectivity on the capillaries modified with NPs, functionalized with quaternary ammonium groups. NS affect the separation selectivity of aminoacids by interacting with these analytes, while for fluoroquinoline antibiotics NS act as an agent generating the reversed electroosmotic flow ( EOF ). The modification of fused silica capillary walls by NS with molecular mass of 400 kDa prevented the sorption of biogeniс amines and lyzocyme protein during their electrophoretic separation. Keywords : capillary electrophoresis, nanoparticles, coatings of fused silica capillary walls DOI: http://dx.doi.org/10.15826/analitika.2019.23.2.006 (Russian) D.A. Polikarpova 1 , D.V. Makeeva 1 , L.A. Kartsova 1 , V.A. Davankov 2 , L.A. Pavlova 2 1 Saint-Petersburg State University, Institute of Chemistry, Universitetskii pr. 26., St. Petersburg, Petergof, 198504, Russian Federation 2 A.N. Nesmeyanov Institute of Organoelement Compounds of Russian Academy of Sciences, Vavilova St. 28, Moscow, 119334, Russian Federation

The recombination activity of intragrain defects in multicrystalline silicon is investigated by the electron or laser beam induced current methods. The interrelation of the grain orientation with the character of the distribution of intragrain defects (dislocations and impurity inclusions) and their recombination activity is revealed. The defect grain structure is investigated using various etching procedures to reveal the defects. It is shown that the defect density and distribution in the grains depend on their orientation relative the growth axis. Therefore, it is intragrain defects and impurities that are to a large degree responsible for degradation of the nonequilibrium carrier lifetime when compared with grain boundaries.

AbstractThe recombination activity of intragrain defects in multicrystalline silicon is investigated by the electron or laser beam induced current methods. The interrelation of the grain orientation with the character of the distribution of intragrain defects (dislocations and impurity inclusions) and their recombination activity is revealed. The defect grain structure is investigated using various etching procedures to reveal the defects. It is shown that the defect density and distribution in the grains depend on their orientation relative the growth axis. Therefore, it is intragrain defects and impurities that are to a large degree responsible for degradation of the nonequilibrium carrier lifetime when compared with grain boundaries.

Novel hydrophilic ionic polymer nanoparticles based on the N-alkylated hypercrosslinked poly-4-vinylpyridine (nanosponges ‒ NS ) have porous structure, pH-independent positive charge and contain the aromatic rings. These nanosponges have not yet been studied in the capillary electrophoresis mode, but their characteristics suggest the possibility of creating the fused silica capillary walls coating for the separation of anionic and cationic analytes. In the current research, the authors, for the first time, have proposed the approaches to the formation of coatings based on the nanosponges with a molecular weight of 400 and 10 kDa. It was established that the stability of such coatings could be achieved by the introduction of NS into the background electrolyte. The pH range of background electrolytes for the subsequent electrophoretic experiments was determined to be from 4 to 9. The NS-based coatings were compared with the previously investigated coatings based on the crosslinked polystyrene nanoparticles ( NPs ), functionalized with the quaternary ammonium groups. Capillaries modified with NS (400 kDa) were tested for the electrophoretic separations of wide range of analytes: carboxylic acids, aminoacids, fluoroquinoline antibiotics, biogenic amines, and proteins. The separation selectivity of carboxylic acids on the NS-modified capillaries was different from the separation selectivity on the capillaries modified with NPs, functionalized with quaternary ammonium groups. NS affect the separation selectivity of aminoacids by interacting with these analytes, while for fluoroquinoline antibiotics NS act as an agent generating the reversed electroosmotic flow ( EOF ). The modification of fused silica capillary walls by NS with molecular mass of 400 kDa prevented the sorption of biogeniс amines and lyzocyme protein during their electrophoretic separation. Keywords : capillary electrophoresis, nanoparticles, coatings of fused silica capillary walls DOI: http://dx.doi.org/10.15826/analitika.2019.23.2.006 (Russian) D.A. Polikarpova 1 , D.V. Makeeva 1 , L.A. Kartsova 1 , V.A. Davankov 2 , L.A. Pavlova 2 1 Saint-Petersburg State University, Institute of Chemistry, Universitetskii pr. 26., St. Petersburg, Petergof, 198504, Russian Federation 2 A.N. Nesmeyanov Institute of Organoelement Compounds of Russian Academy of Sciences, Vavilova St. 28, Moscow, 119334, Russian Federation

A method for estimating the native gold composition in micron‐ and submicron‐sized inclusions in the matrix of a sulfide mineral with electron probe X‐ray microanalysis is proposed. Such inclusion sizes are comparable with or less than the X‐ray generation volume, and therefore, the analytical signal is a mixture of signals from the matrix elements and the inclusion elements, which significantly complicates the quantification. The proposed procedure is based upon the extrapolation of the trend of the dependence of the measured elemental contents in the inclusions, for example, Au or Ag, versus the content of matrix elements, namely, S, Fe, and As. To define the influence of the inclusion size on the intensity of the excited X‐rays, the trajectories of the electrons in a sample were simulated by the Monte Carlo method. It was found that the trends in the behavior calculated by the Monte Carlo method are consistent with the data measurements of an artificial pyrite sample with a sprayed pure gold layer (approximately 1 μm thick) arranged perpendicular to the sample surface. The measurements were performed on a Superprobe JXA‐8200 microanalyzer. The proposed method was demonstrated by analyzing natural, finely dispersed gold inclusions in arsenopyrite. This approach made it possible to evaluate the Au and Ag contents in the approximately 1 μm inclusions and assess the uncertainty of the measurement.

The excess carrier lifetime (τ) distribution in multicrystalline silicon grown by the Bridgman technique from high-purity metallurgical silicon (HPMG-Si) is studied. The features of the variation in τ, caused by the grain-boundary structure of ingots, are revealed. The grain boundaries, dislocations, and impurity microinclusions are studied by electron probe microanalysis (EPMA) and scanning electron microscopy (SEM) using selective acid etching. The electrical activity of extended defects is measured by the electronbeam- induced-current (EBIC) method.

AbstractThe excess carrier lifetime (τ) distribution in multicrystalline silicon grown by the Bridgman technique from high-purity metallurgical silicon (HPMG-Si) is studied. The features of the variation in τ, caused by the grain-boundary structure of ingots, are revealed. The grain boundaries, dislocations, and impurity microinclusions are studied by electron probe microanalysis (EPMA) and scanning electron microscopy (SEM) using selective acid etching. The electrical activity of extended defects is measured by the electronbeam- induced-current (EBIC) method.