Open AccessFeatures of the physicochemical properties of narrow fractions of aggregates of diamond nanopowders modified with iron ions
Author(s) -
H. D. Ilnytska,
O. B. Loginova,
V. V. Smokvyna,
І. М. Зайцева,
О. V. Dovha
Publication year - 2020
Publication title -
poverhnostʹ
Language(s) - English
Resource type - Journals
eISSN - 2617-5983
pISSN - 2617-5975
DOI - 10.15407/surface.2020.12.161
Subject(s) - diamond , diamagnetism , particle (ecology) , ion , materials science , analytical chemistry (journal) , chemistry , chemical engineering , magnetic field , chromatography , metallurgy , oceanography , physics , organic chemistry , quantum mechanics , engineering , geology
The paper presents the results of a study of the physical and chemical properties of narrow fractions of diamond nanopowders with a low content of non-diamond carbon grade ASUD-99. Six fractions with different average diameters of diamond particle aggregates from 28.785 to 3.891 μm were obtained by separating a 0.2 % aqueous suspension of the initial powders by the sedimentation method. It has been found that the smallest aggregates consist of larger particles with a smaller specific surface area and a lower interaction energy between them. This conclusion is confirmed by a decrease in the porosity of the obtained aggregates. So, if the pore volume in the largest aggregates of diamond particles is 0.859 ml/g, then in the smallest 0.550 ml/g, while the pore radius of diamond aggregates in different fractions changes insignificantly. Separation in a magnetic field at different currents of diamond nanopowders with a specific magnetic susceptibility of 0.52×10-8 m3 kg, treated with a solution of 5 % iron chloride, made it possible to obtain five fractions that differ from each other in specific magnetic susceptibility (c) – from magnetic fractions with c = 4.30×10-8 m3/kg to diamagnetic – with c = –0.11×10-8 m3/kg. It is shown that the modification of diamond nanopowders with iron ions increases the separation selectivity and makes it possible to isolate diamagnetic powders.