Search academic texts

Information × Registration Number 0225U000095, (0123U102132) , R & D reports Title Development of metal-filled nanostructured materials for protection against electromagnetic radiation popup.stage_title Оптимізація методів синтезу нанопорошків на основі металів-феромагнетиків та встановлення впливу окремих фізичних впливів (зовнішнє магнітне поле, ультразвукове опромінення) на здатність наносистем до самоорганізації. Head Kytsia Andrii R., Кандидат хімічних наук Registration Date 04-01-2025 Organization Department of Physical Chemistry of Combustible Minerals of the Institute of Physical and Organic Chemistry and Coal Chemistry. L.M. Litvinenko of the National Academy of Sciences of Ukraine popup.description1 The goal of scientific research is to establish the regularities of the formation and optimization of the conditions for the synthesis of nanoparticles of ferromagnetic metals (iron, cobalt, nickel) capable of self-organization and to test their use as fillers in polymer composite materials for their use in protecting equipment from electromagnetic radiation. popup.description2  In order to optimize the synthesis methods of metal nanofillers to electrically conductive compositions with shielding properties, the influence of the stirring speed of the reaction mixture, magnetic field and ultrasonic radiation on the formation features and properties of nickel nanoparticles (NiNPs) and bimetallic Ni-Co nanoparticles was investigated. It was found that the intensity of stirring and the application of an external magnetic field do not affect the kinetic parameters (duration of the induction period and total reaction duration) of the process. At the same time, when the reaction is carried out in an ultrasonic field, the duration of the induction period is reduced by 5–10 times depending on the composition of the reaction mixture. The electrical conductivity of the obtained nanopowders was investigated and it was found that the value of the specific electrical conductivity increases with increasing intensity of physical influences on the course of the formation process of (bi)metallic nanoparticles in the series: “stirring intensity – external magnetic field – ultrasonic radiation – ultrasonic radiation + external magnetic field”. Using SEM and XRD, it was found that all the obtained NiNPs are spherical in shape with a particle size of ~200 nm, and the size of nickel crystallites, calculated according to the Scherrer equation, does not depend on the synthesis conditions and is within 14 - 15 nm. At the same time, it was found that nickel nanopowders, which have low electrical conductivity, form compact agglomerates of nanoparticles, unlike NiNPs obtained under the influence of external physical factors. Based on the analysis of the diffractograms of NiNPs using the Williams-Gall equation, it was found that the electrical conductivity of nanopowders critically depends on the defects in the structure of nanoparticles - with an increase in the number of defects, the electrical conductivity of NiNPs increases. Product Description popup.authors Bazyliak Liliia I. Balashova Iryna Ye. Halatyn Ihor Z. Piliuk Yaroslav V. Stetskiv Andrii O. Fedorchuk Anatolii O. Fedorchuk Andrii A. popup.nrat_date 2025-01-04 Close