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Abramovskis V, Zalite I, Maiorov M, Baronins J, Singh AK, Lapkovskis V, Goel S, Shishkin A. High-Temperature, Lightweight Ceramics with Nano-Sized Ferrites for EMI Shielding: Synthesis, Characterisation, and Potential Applications. MATERIALS (BASEL, SWITZERLAND) 2023; 16:7615. [PMID: 38138758 PMCID: PMC10744912 DOI: 10.3390/ma16247615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 12/01/2023] [Accepted: 12/05/2023] [Indexed: 12/24/2023]
Abstract
The present study focuses on the synthesis and characterisation of a lightweight ceramic material with electromagnetic interference (EMI) shielding properties, achieved using mullite containing micrometre-sized hollow spheres (cenospheres) and CoFe2O4 nanoparticles. This research explores compositions with varying CoFe2O4 contents ranging from 0 up to 20 wt.%. Conventional sintering in an air atmosphere is carried out at a temperature between 1100 and 1300 °C. The addition of ferrite nanoparticles was found to enhance the process of sintering cenospheres, resulting in improved material density and mechanical properties. Furthermore, this study reveals a direct correlation between the concentration of ferrite nanoparticles and the electromagnetic properties of the material. By increasing the concentration of ferrite nanoparticles, the electromagnetic shielding effect of the material (saturation magnetisation (Ms) and remanent magnetisation (Mr)) was observed to strengthen. These findings provide valuable insights into designing and developing lightweight ceramic materials with enhanced electromagnetic shielding capabilities. The synthesized ceramic material holds promise for various applications that require effective electromagnetic shielding, such as in the electronics, telecommunications, and aerospace industries.
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Affiliation(s)
- Vitalijs Abramovskis
- Laboratory of Ecological Solutions and Sustainable Development of Materials, Institute of General Chemical Engineering, Faculty of Materials Science and Applied Chemistry, Riga Technical University, Pulka 3, K-3, LV-1007 Riga, Latvia; (V.A.); (J.B.); (V.L.)
| | - Ilmars Zalite
- Institute of Materials and Surface Technologies, Riga Technical University, P. Valdena Iela 7, LV-1048 Riga, Latvia;
| | - Mikhail Maiorov
- Institute of Physics, University of Latvia, Miera Iela 32, LV-2169 Salaspils, Latvia;
| | - Janis Baronins
- Laboratory of Ecological Solutions and Sustainable Development of Materials, Institute of General Chemical Engineering, Faculty of Materials Science and Applied Chemistry, Riga Technical University, Pulka 3, K-3, LV-1007 Riga, Latvia; (V.A.); (J.B.); (V.L.)
| | | | - Vjaceslavs Lapkovskis
- Laboratory of Ecological Solutions and Sustainable Development of Materials, Institute of General Chemical Engineering, Faculty of Materials Science and Applied Chemistry, Riga Technical University, Pulka 3, K-3, LV-1007 Riga, Latvia; (V.A.); (J.B.); (V.L.)
| | - Saurav Goel
- School of Engineering, London South Bank University, London SE1 0AA, UK;
- Department of Mechanical Engineering, University of Petroleum and Energy Studies, Dehradun 248007, India
| | - Andrei Shishkin
- Laboratory of Ecological Solutions and Sustainable Development of Materials, Institute of General Chemical Engineering, Faculty of Materials Science and Applied Chemistry, Riga Technical University, Pulka 3, K-3, LV-1007 Riga, Latvia; (V.A.); (J.B.); (V.L.)
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Li W, Yan J, Xu W, Zhang LY. Magnetic nanoparticles modified with a copper(i) complex as a novel and efficient reusable catalyst for A 3 coupling leading to C-N bond formation. RSC Adv 2023; 13:28964-28974. [PMID: 37795047 PMCID: PMC10545981 DOI: 10.1039/d3ra04871c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Accepted: 09/21/2023] [Indexed: 10/06/2023] Open
Abstract
Propargylamines are an important and valuable family of nitrogen-containing compounds with many applications in the fields of medical, industrial, and chemical processes. One-pot multicomponent A3 coupling reactions of aldehydes, amines, and alkynes in the presence of transition metals as catalysts is an efficient strategy for preparing propargylamines. In this study, we fabricated a novel magnetically reusable copper nanocatalyst [Fe3O4-BIm-Pyrim-CuI] through the immobilization of the copper(i) complex on the surface of the magnetic nanoparticles modified with benzimidazole-pyrimidine ligand and evaluated its catalytic activity in the preparation of propargylamines through one-pot multicomponent A3 coupling reactions of aldehydes, amines, and alkynes. Under this catalytic system, aryl substrates with both electron-donating and electron-withdrawing substituents also gave the desired products in excellent yields under standardized conditions. The Fe3O4-BIm-Pyrim-CuI catalyst was easily separated using an external magnet, and the recovered catalyst was reused in 8 cycles without significant loss of activity.
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Affiliation(s)
- Wei Li
- College of Science and Engineering, Jiaozuo Normal College Jiaozuo Henan 454000 China
| | - Jinlong Yan
- College of Science and Engineering, Jiaozuo Normal College Jiaozuo Henan 454000 China
| | - Wenjing Xu
- College of Science and Engineering, Jiaozuo Normal College Jiaozuo Henan 454000 China
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