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Sun WF, Sun PB. Electrical Insulation and Radar-Wave Absorption Performances of Nanoferrite/Liquid-Silicone-Rubber Composites. Int J Mol Sci 2022; 23:ijms231810424. [PMID: 36142338 PMCID: PMC9499675 DOI: 10.3390/ijms231810424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 09/06/2022] [Accepted: 09/06/2022] [Indexed: 11/16/2022] Open
Abstract
Novel radar-wave absorption nanocomposites are developed by filling the nanoscaled ferrites of strontium ferroxide (SrFe12O19) and carbonyl iron (CIP) individually into the highly flexible liquid silicone rubber (LSR) considered as dielectric matrix. Nanofiller dispersivities in SrFe12O19/LSR and CIP/LSR nanocomposites are characterized by scanning electronic microscopy, and the mechanical properties, electric conductivity, and DC dielectric-breakdown strength are tested to evaluate electrical insulation performances. Radar-wave absorption performances of SrFe12O19/LSR and CIP/LSR nanocomposites are investigated by measuring electromagnetic response characteristics and radar-wave reflectivity, indicating the high radar-wave absorption is dominantly derived from magnetic losses. Compared with pure LSR, the SrFe12O19/LSR and CIP/LSR nanocomposites represent acceptable reductions in mechanical tensile and dielectric-breakdown strengths, while rendering a substantial nonlinearity of electric conductivity under high electric fields. SrFe12O19/LSR nanocomposites provide high radar-wave absorption in the frequency band of 11~18 GHz, achieving a minimum reflection loss of −33 dB at 11 GHz with an effective absorption bandwidth of 10 GHz. In comparison, CIP/LSR nanocomposites realize a minimum reflection loss of −22 dB at 7 GHz and a remarkably larger effective absorption bandwidth of 3.9 GHz in the lower frequency range of 2~8 GHz. Radar-wave transmissions through SrFe12O19/LSR and CIP/LSR nanocomposites in single- and double-layered structures are analyzed with CST electromagnetic-field simulation software to calculate radar reflectivity for various absorbing-layer thicknesses. Dual-layer absorbing structures are modeled by specifying SrFe12O19/LSR and CIP/LSR nanocomposites, respectively, as match and loss layers, which are predicted to acquire a significant improvement in radar-wave absorption when the thicknesses of match and loss layers approach 1.75 mm and 0.25 mm, respectively.
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Affiliation(s)
- Wei-Feng Sun
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798, Singapore
- Correspondence:
| | - Peng-Bo Sun
- School of Electrical and Electronic Engineering, Harbin University of Science and Technology, Harbin 150080, China
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Song W, Sun Y, Yu TJ, Fan YZ, Sun Z, Han B. Investigation of Electrical Properties of BiFeO 3/LDPE Nanocomposite Dielectrics with Magnetization Treatments. Polymers (Basel) 2021; 13:polym13162622. [PMID: 34451166 PMCID: PMC8399396 DOI: 10.3390/polym13162622] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 08/03/2021] [Accepted: 08/03/2021] [Indexed: 11/16/2022] Open
Abstract
The purpose of this paper is to study the effect of nano-bismuth ferrite (BiFeO3) on the electrical properties of low-density polyethylene (LDPE) under magnetic-field treatment at different temperatures. BiFeO3/LDPE nanocomposites with 2% mass fraction were prepared by the melt-blending method, and their electrical properties were studied. The results showed that compared with LDPE alone, nanocomposites increased the crystal concentration of LDPE and the spherulites of LDPE. Filamentous flake aggregates could be observed. The spherulite change was more obvious under high-temperature magnetization. An agglomerate phenomenon appeared in the composite, and the particle distribution was clear. Under high-temperature magnetization, BiFeO3 particles were increased and showed a certain order, but the change for room-temperature magnetization was not obvious. The addition of BiFeO3 increased the crystallinity of LDPE. Although the crystallinity decreased after magnetization, it was higher than that of LDPE. An AC test showed that the breakdown strength of the composite was higher than that of LDPE. The breakdown strength increased after magnetization. The increase of breakdown strength at high temperature was less, but the breakdown field strength of the composite was higher than that of LDPE. Compared with LDPE, the conductive current of the composite was lower. So, adding BiFeO3 could improve the dielectric properties of LDPE. The current of the composite decayed faster with time. The current decayed slowly after magnetization.
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Affiliation(s)
- Wei Song
- Key Laboratory of Engineering Dielectrics and Its Application, Ministry of Education, Heilongjiang Provincial Key Laboratory of Dielectric Engineering, School of Electrical and Electronic Engineering, Harbin University of Science and Technology, Harbin 150080, China; (T.-J.Y.); (Z.S.); (B.H.)
- Correspondence: (W.S.); (Y.S.); Tel.: +86-138-0451-6257 (W.S.); +86-159-4604-0553 (Y.S.)
| | - Yu Sun
- Key Laboratory of Engineering Dielectrics and Its Application, Ministry of Education, Heilongjiang Provincial Key Laboratory of Dielectric Engineering, School of Electrical and Electronic Engineering, Harbin University of Science and Technology, Harbin 150080, China; (T.-J.Y.); (Z.S.); (B.H.)
- Correspondence: (W.S.); (Y.S.); Tel.: +86-138-0451-6257 (W.S.); +86-159-4604-0553 (Y.S.)
| | - Tian-Jiao Yu
- Key Laboratory of Engineering Dielectrics and Its Application, Ministry of Education, Heilongjiang Provincial Key Laboratory of Dielectric Engineering, School of Electrical and Electronic Engineering, Harbin University of Science and Technology, Harbin 150080, China; (T.-J.Y.); (Z.S.); (B.H.)
| | - Yu-Zhang Fan
- Shandong Electric Power Equipment Co., Ltd., Licheng District, Jinan 250100, China;
| | - Zhi Sun
- Key Laboratory of Engineering Dielectrics and Its Application, Ministry of Education, Heilongjiang Provincial Key Laboratory of Dielectric Engineering, School of Electrical and Electronic Engineering, Harbin University of Science and Technology, Harbin 150080, China; (T.-J.Y.); (Z.S.); (B.H.)
| | - Bai Han
- Key Laboratory of Engineering Dielectrics and Its Application, Ministry of Education, Heilongjiang Provincial Key Laboratory of Dielectric Engineering, School of Electrical and Electronic Engineering, Harbin University of Science and Technology, Harbin 150080, China; (T.-J.Y.); (Z.S.); (B.H.)
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