Role of humic substances in the formation of nanosized particles of iron corrosion products

Опубликовано в English

Particle size distribution during a corrosion reactionRole of humic substances in the formation of nanosized particles of iron corrosion products. Pankratov D.A., Anuchina M.M. //Russian Journal of Physical Chemistry A. 2017. V.91. №2. P.233-239.Search the full text below. Ищи полный текст ниже.

The corrosion of metallic iron in aqueous solutions of humic substances (HS) with limited access to air is studied. The HS are found to exhibit multiple functions. Acid–base, redox, and surfactant properties, along with the ability to form complexes with iron in solution, are displayed in the corrosion process. Partial reduction of the HS during the corrosion reaction and their adsorption onto the main corrosion product (Fe3O4 nanoparticles) are observed.

Properties of Iron-Containing Nanohydroxyapatite-Based Composites

Опубликовано в English

EPR spectra of the (a) N-a and (b) N-c samplesProperties of Iron-Containing Nanohydroxyapatite-Based Composites. Pankratov D.A., Dolzhenko V.D., Ovchenkov E.A., Anuchina M.M., Severin A.V. //Inorganic Materials. 2017. V.53. №1. P.89-98.Search the full text below. Ищи полный текст ниже.

The paramagnetic properties of compounds resulting from the synthesis of nanohydroxyapatite in the presence of Fe(III) ions have been studied by electron paramagnetic resonance, Mössbauer spectroscopy, and magnetochemistry. Based on the obtained results on the mechanism of the reaction between an orthophosphoric acid solution and an aqueous calcium hydroxide suspension, we have found conditions for incorporating Fe(III) impurity ions into hydroxyapatite. We have studied samples differing in the sequence in which reagents were mixed and in hydroxyapatite crystallite formation conditions. It has been shown that, in all instances, the composition and properties of the iron-containing phases in the composites depend significantly on both synthesis and heat treatment conditions.

Сорбция гуминовых веществ на слабоосновном анионите: взаимосвязь со структурой адсорбата

Опубликовано в Russian

Зависимость изотерм сорбции ГВ на анионите АНС от относительного содержания ароматического углерода к алифатическому в рамках универсальной моделиСорбция гуминовых веществ на слабоосновном анионите: взаимосвязь со структурой адсорбата. Панкратов Д.А., Анучина М.М., Борисова Е.М., Воликов А.Б., Константинов А.И., Перминова И.В. //Журнал физической химии. 2017. Т.91. №6. С.1042-1048.Search the full text below. Ищи полный текст ниже.

Изучены процессы адсорбции на макропористой слабоосновной анионообменной смоле широкой выборки гуминовых веществ (ГВ) различного происхождения и фракционного состава. Установлено, что природа гуминовых веществ существенно влияет как на эффективность сорбции, так и на механизм взаимодействия с адсорбентом. Показана зависимость полученных термодинамических параметров сорбционных процессов для широкой выборки гуминовых веществ от их происхождения, состава и строения. Сделан вывод, что полученные результаты могут быть полезны для прогнозирования сорбционных свойств слабоосновных анионообменных смол по отношению к гуминовым веществам известного происхождения и структурно-группового состава.

Synthesis of nanohydroxyapatite in the presence of iron (III) ions

Опубликовано в English

Room-temperature Mössbauer spectra of the 2-x samples, models for their description (left panels), and the corresponding quadrupole splitting probability distribution functions (right panels)Synthesis of nanohydroxyapatite in the presence of iron (III) ions. Severin A.V., Pankratov D.A. //Russian Journal of Inorganic Chemistry. 2016. V.61. №3. P.265-272.Search the full text below. Ищи полный текст ниже.

The effect of small amounts of iron (III) ions on the morphology, phase composition, and structure of the products of the hydroxyapatite (HAP) synthesis has been studied by electron microscopy, X-ray powder diffraction, and Mossbauer spectroscopy methods. It has been demonstrated that the introduction of dopant iron (III) ions into the reaction mixture at different stages of HAP formation makes it possible to control crystal growth, morphology, and phase composition. The iron ions are not incorporated into the HAP crystal structure; rather, they form their proper nanophase, as well as adsorption clusters on the HAP surface.



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Мессбауэровская диагностика функциональных материалов

Мессбауэровская диагностика функциональных материалов