Materials Today Communications
·
2022
·
IF 3.662
Xiaoshan Zhang,Yonggang Jiang,Nana Xu,Haiyan Liu,Nan Wu,Cheng Han,Bing Wang,Yingde Wang
The radome and antenna windows of aerospace aircrafts highly require multifunctional materials that are thermal stable, capable of wave-transparent and have excellent thermal insulation performance. Due to the SiO 2 aerogel with high thermal stability, low dielectric constant and ultralow thermal conductivity , they are considered as promising high-temperature thermal insulating and wave-transparent materials. In this work, the SiBNO fibers with good wave-transparent performance were used as reinforcements to prepare SiO 2 aerogel composites (SiBNO f /SiO 2 ACs) by sol-gel impregnating and supercritical drying method. The prepared SiBNO f /SiO 2 ACs exhibit integrated performances of excellent fire resistance, high-temperature stability (1100 °C in Air), high mechanical properties (compressive strength is 1.89 ± 0.14 MPa at 40 % strain and bending strength is 1.93 ± 0.03 MPa), ultralow thermal conductivity (0.029 W m −1 K −1 at 25 °C and 0.051 W m −1 K −1 at 1100 °C) and good wave-transparent property (dielectric constant<1.45, loss tangent<0.01 in 4–18 GHz). All of these characteristics are related to the unique nanoporous structure of SiO 2 aerogel and intrinsic nature of SiBNO fibers and SiO 2 aerogel. The prepared multifunctional SiBNO f /SiO 2 ACs have great potential to be used in harsh environment for thermal insulation and wave-transparent.
研究领域:
材料科学
·
航空航天工程
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2020
·Vol. 31
·期 18
·16073-16086
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IF 2.22
Mao Yumeng,Yao Zhengjun,Zhou Jintang,Wei Bo,Lei Lei,Fan Huiyuan
In this work, stearyltrimethylammoium bromide (STAB) was used to modify montmorillonite (MMT). Subsequently, the modified organic montmorillonite (OMMT) was added into 4,4′-Bismaleimidodiphenyl methane (BDM) and 2,2′-Diallylbisphenol A (DBA) copolymerization system to prepare BDM/OMMT wave-transparent nanocomposites with 0–5 wt% OMMT content. It is found that the addition of OMMT improves the microstructure, thermal properties, and wave-transparent properties of BDM composites. At the addition of 2 wt%, the thermal stability of the resin system is the best, and the fracture morphology changes from brittle fracture characteristics to ductile fracture characteristics. Meanwhile, in X-band (8–12 GHz), OMMT-2 wt% with the thickness less than 2 mm or within 8–10 mm has excellent transmittance (> 90%). Moreover, the effect of temperature change on the wave-transparent performance of BDM/OMMT nanocomposites is investigated. From room temperature to 200 °C, the stability of high-temperature transmittance of OMMT-2 wt% is enhanced, and it still has good transmittance (> 90%) within in a wide thickness range at 200 °C. The enhancement of these properties is closely correlated with the interaction interface formed between OMMT and BDM resin matrix. The addition of OMMT can increase the design selection of BDM resin system and expand its application as a wave-transparent material.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2024
·
IF 11.2
Zhen Yu,Mingwei Ma,Ziyu Liu,Zhengyi Zhang,Chunjia Luo,Tiantian Zhang,Jie Kong
Polymer-derived ceramics (PDCs) is a promising way to prepare ceramic-based electromagnetic functional materials, which can conveniently modulate the composition and dielectric properties of the ceramics. In this paper, SiBCN ceramic matrix composites with excellent high-temperature wave-transparent performance were prepared through PDC method. Three hyperbranched polyborosilazanes (PBSZs) were prepared by adjusting the type of chlorosilane monomers containing different numbers of methyl groups. The carbon element of pyrolytic ceramics was tuned by adjusting the molecular structure of the precursor and the pyrolysis temperature. The lower the methyl number and pyrolysis temperature, the lower the dielectric constant of the polymer-derived SiBCN ceramics, which is favorable for electromagnetic wave (EMW) transmittance. The average EMW transmittance of SiBCN-C pyrolyzed from hyperbranched PBSZ using trichlorosilane at 1000 ℃ was 90.56% at room temperature. More excitingly, the excellent wave-transparent performance was also maintained in the temperature range of 100-800 ℃. At the test temperature of 800 ℃, SiBCN-C-1000 still had excellent wave-transparent performance with minimum and average EMW transmittance of 76.13% and 88.96%, respectively. This paper provided a new idea for the preparation of high-temperature wave-transparent SiBCN composite ceramics.
研究领域:
材料科学
·
电磁功能材料
✓ 已验证
DOI
高影响因子
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
·
2025
·
IF 8.9
Xiaoyu Weng,Yu Song,Zhiyuan Xiong,Jian Hu,Jin Long
Poly(p-phenylene benzobisoxazole) (PBO)/Polytetrafluoroethylene (PTFE) composite materials exhibit substantial potential for wave-transparent applications due to the excellent dielectric properties of raw materials. In this work, we reported a facile paper-making method for preparing large-area micro-nano PBO/PTFE composite papers with uniform and compact structure by compounding PBO chopped fibers (PCFs), PBO nanofibers (PNFs), and PTFE. Notably, the simultaneous formation of an interconnected PBO fiber network and PTFE matrix promotes optimal structural uniformity, while the introduction of PNFs between PCFs and PTFE acts as an interface compatibilizer that effectively reduces interface defects in the papers. These structural advantages contribute to the composite papers’ exceptional dielectric properties (dielectric constant as low as 2.142 and dielectric loss as low as 0.001 at 10 GHz) and high wave-transmission efficiency (exceed 95.8 % across 2–22 GHz). Meanwhile, the composite papers feature favorable thermo-mechanical property and UV aging resistance, demonstrating their high potential in wave-transparent applications.
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2024
·Vol. 59
·期 4
·1312-1326
·
IF 3.5
Song Keru,Huang Siyu,Wang Jianwen,Shi Fengyue,Hu Songyu,Zhao Guangdong
Novel Si 3 N 4 /PAN/SiZrOCN ceramic aerogel composites, which have excellent wave transmission functions, were prepared through electrospinning, freeze-drying, and high-temperature pyrolysis. Polyvinyl alcohol was used as the aerogel carbon skeleton, polystyrene served as the pore-forming substance, Si 3 N 4 /PAN fiber was used as the reinforcement material. The pore size distribution and dielectric properties of the composites were systematically studied at different pyrolysis temperatures. An increase in pyrolysis temperatures led to a decrease in the specific surface area and dielectric constant. Fourier infrared spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction were employed to investigate the polymerization mechanism and ceramic process of the precursor. The Brunauer–Emmett–Teller test revealed that the maximum specific surface area of Si 3 N 4 /PAN/SiZrOCN ceramic aerogel composites was 109.261 m 2 /g, and the average pore size was 4.56 nm when sintered at 600 °C. The dielectric properties test results showed a dielectric constant ranging between 3.1 and 3.7 and a dielectric loss tangent value between 2.6 × 10 –3 and 1.6 × 10 –2 for the sample. Si 3 N 4 /PAN/SiZrOCN ceramic aerogel composites exhibited excellent dielectric properties at room temperature and demonstrated exceptional dielectric stability across different frequency bands (1.8–18.0 GHz), making them a potential high-temperature wave-transmittance material.
研究领域:
材料科学
·
无机化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）