JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
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IF 6.371
Jie Liu,Yurun Feng,Chunmiao Liu,Yanchun Tong,Haibin Sun,Hui Peng,Shigang Wu,Junbin Lu,Hongyu Gong,Xue Guo,Jiao Li
The SiBCN composite fibers with strong electromagnetic wave (EMW) absorption performance were successfully prepared via polymer-derived ceramics (PDCs) and electrospinning methods at relatively lower preparation temperature. The results showed that the in-situ generated free carbon which existed in the matrix in the form of simple substance and was characterized by low crystallinity. The graphite carbon improved the dielectric loss and properties of SiBCN composite fibers. In particular for the SiBCN composite fibers pyrolyzed at 1300 °C, the in-situ generated nano β-SiC crystallization increased the EMW absorption performance significantly. The minimum reflection loss (RL min ) of the SiBCN-3 reached − 54.91 dB at 2.35 mm and the effective absorption band (EAB, RL ≤ −10 dB) reached 4.72 GHz (13.28–18 GHz, 1.75 mm). Hence, the SiBCN fibers prepared at relatively lower temperature give good absorption performance and predict a broader application prospect in the field of EMW absorption materials.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
CORROSION SCIENCE
·
2019
·
IF 6.355
Daxin Li,Zhihua Yang,Dechang Jia,Xiaoming Duan,Delong Cai,Shengjin Wang,Jingkun Yuan,Yu Zhou,Dongli Yu,Yongjun Tian
High-temperature oxidation behavior of dense amorphous boron-rich Si 2 B 1-4 C 2 N monoliths in flowing air was studied in detail. The oxidation products are those of amorphous silica and cristobalite that control the diffusion of oxygen inward. Oxygen diffusion leads to a dense and passivating scale, which acts as a barrier to oxygen. Amorphous boron-rich monoliths oxidize through a classical parabolic manner. The amorphous nature, three-layers structure of oxide scale and varying chemical bonds are primarily responsible for the oxidation resistance with respect to the nano monoliths. The increase in boron content is revealed to weaken the oxidation resistance of the amorphous Si 2 B 1-4 C 2 N monoliths.
研究领域:
材料科学
·
无机非金属材料
·
高温功能材料
·
陶瓷基复合材料
·
表面与界面化学
✓ 已验证
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2024
·
IF 5.8
Wenxia Zhu,Xiaohui Xia,Yukun Zheng,Huiming Ji,Dong Su
Precursor derived SiBCN ceramic is considered as promising materials for advanced electromagnetic interference (EMI) shielding. Here, the graphene nanosheet (GNS) aerogel via high-temperature graphitization was used as conductive network for constructing GNS/SiBCN nanocomposites through polyborosilazane (PBSZ) precursor infiltration and pyrolysis. The graphitization process of GNS aerogels increases the electrical conductivity of GNS/SiBCN nanocomposites from 105 to 1168 S·m −1 , and achieves an improved EMI shielding effectiveness (SE Total ) from 24.1 to 39.3 dB. The SiBCN protection endows the nanocomposite with good oxidation resistance at 800 °C in air and high-temperature stability at 1400 °C in Ar. Moreover, the porous GNS/SiBCN nanocomposite with density of 0.11 g·cm −3 was attained by adjusting the PBSZ content of 10 % during the infiltration, further exhibiting a high SE Total of 32.7 dB and a high specific SE Total of 297 dB·g −1 ·cm 3 . Therefore, it’s an ideal route to develop lightweight EMI shielding materials used in high-temperature environment.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
·
IF 4.527
Qingqing Chen,Daxin Li,Zhihua Yang,Dechang Jia,Yu Zhou,Ralf Riedel
Tris(dichloromethylsilylethyl)borane is a compound containing a B–C bond and Cl and H elements. Herein, we propose a novel method to synthesize polyborosilazanes using tris(dichloromethylsilylethyl)borane and boron trichlorosilane as boron sources and hexamethyldisilazane as a nitrogen source. The microstructure and chemical composition of the as-synthesized polyborosilazanes and as-annealed SiBCN ceramics were investigated using Fourier transform infrared spectroscopy , nuclear magnetic resonance spectroscopy , Raman spectroscopy , scanning electron microscope, and transmission electron microscope methods. The organic precursors were converted entirely into inorganic ceramics at 800 °C, and the ceramic yield of the polyborosilazanes was 88% at 1000 °C. SiBCN ceramics with irregular shapes contained chemical bonds of B–N, Si–N, and Si–C at 1500 °C and retained an amorphous structure below 1600 °C. After the first cycle, the fabricated SiBCN ceramic anodes exhibited a reversible capacity of 261.3 mA h/g, which was 2.6 times that reported in the literature (101 mA h/g). The discharge capacity decreased to 157.6 mA h/g after 30 cycles. The satisfactory electrochemical performance of the resulting SiBCN ceramic anodes can be attributed to the formation of conductive carbon species favoring the transport properties of lithium ion .
研究领域:
材料科学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Junpeng Jiang,Liwen Yan,Mengjia Song,Yifan Li,Anran Guo,Haiyan Du,Jiachen Liu
Thermal insulation and electromagnetic wave (EMW) absorption integrated materials with lightweight are highly desirable in hypersonic vehicles and military application, as they provide both aerodynamic heat resistance and EMW stealth capability. Herein, a C/SiC/SiBCN ceramic composite aerogel was developed using a novel strategy combining in situ chemical vapor deposition of SiC nanofibers with the polymer-derived ceramic (PDC) aerogel method. The microstructure, phase composition, thermal insulation, mechanical properties and EMW absorption performances of the composite aerogel were thoroughly investigated. The resulting C/SiC/SiBCN composite aerogel with three impregnation-pyrolysis cycles demonstrates improved mechanical properties, with the compressive strength increasing from 0.21 MPa to 0.48 MPa compared to pure SiBCN aerogel. Additionally, the composite aerogel shows a low thermal conductivity of 0.049 W/mK and a low density of 0.116 g/cm 3 . Moreover, the C/SiC/SiBCN composite aerogel exhibits outstanding EMW absorption properties, achieving a minimum reflection loss of −45.7 dB and an effective bandwidth of 5.3 GHz. Owing to the integration of EMW absorption and thermal insulation properties, the C/SiC/SiBCN composite aerogel offers promising potential for developing integrated microwave absorption and thermal insulation materials for high-speed vehicles.
研究领域:
材料科学
·
航空航天工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Junpeng Jiang,Yunjia Xue,Jiangtao Li,Chensi Zhang,Xiaoxia Hu,Liwen Yan,Anran Guo,Haiyan Du,Jiachen Liu
Polymer-derived SiBCN ceramic aerogels have attracted extensive attention in recent years due to the excellent electromagnetic wave absorption and thermal insulation properties. With these merits, SiBCN aerogels are promising for the application of high-speed vehicles requiring thermal and electromagnetic shielding. However, the brittleness and poor mechanical property of SiBCN aerogel seriously hinder its practical applications. In this paper, SiBCN/SiBCN nf composite ceramic aerogels with enhanced mechanical property were prepared by combining electrospinning technique with simultaneous pyrolysis process of polyborosilane (PBS) fibers and precursor aerogels. The effect of varying fiber content on the density, mechanical property, thermal insulation as well as microwave absorption performance of the composite aerogel was investigated. In addition, the underlying toughness mechanism of the SiBCN/SiBCN nf composite ceramic aerogel was elucidated. The compressive strength of the SiBCN/SiBCN nf composite aerogel increased from 0.29 MPa to 1.62 MPa. Importantly, while the mechanical strength of the composite aerogel increased by about 5.5 times, SiBCN/SiBCN nf aerogel still exhibits low density of 0.105 g/cm³, low thermal conductivity of 0.048 W/mK and a minimum reflection loss (RL min ) of −20 dB. Owing to the integration of electromagnetic wave (EMW) absorption and thermal insulation properties, SiBCN/SiBCN nf aerogels pave the way for the construction of thermal and electromagnetic shielding material for high-speed vehicles.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Junpeng Jiang,Liwen Yan,Jiangtao Li,Yunjia Xue,Chensi Zhang,Xiaoxia Hu,Anran Guo,Haiyan Du,Jiachen Liu
Owing to tunable dielectric properties, light weight and high porosity, polymer-derived SiBCN ceramic aerogels possess significant application prospects in electromagnetic wave (EMW) absorption and thermal insulation. However, due to inadequate oxidation resistance, the structural collapse and performance deterioration of SiBCN aerogels will easily occur in high-temperature aerobic environments, limiting their application. Herein, to address this issue, a novel and straightforward strategy based on typical polymer-derived-ceramic (PDC) aerogel method and impregnation with boehmite sol was proposed for synthesizing SiBCN/Al 2 O 3 composite ceramic aerogels. The microstructure, phase composition, thermal insulation, oxidation resistance and EMW absorption properties of SiBCN/Al 2 O 3 ceramic aerogels were investigated. The resulting SiBCN/Al 2 O 3 composite aerogel demonstrates superior high-temperature structural stability, exhibiting an ultra-low linear shrinkage of only 6.5 % following heat treatment at 1200 °C for 2 h in air. Additionally, the composite aerogel shows a low thermal conductivity of 0.039 W/mK and a low density of 0.112 g/cm 3 . The SiBCN/Al 2 O 3 composite aerogel, composed of dielectric SiBCN, conductive free carbon, and insulating alumina, demonstrates outstanding EMW absorption properties with a minimum reflection loss of −48.6 dB and an effective bandwidth of 5.8 GHz. The enhanced microwave absorption performance is mainly attributed to the improved impedance matching, multiple reflection, and enhanced interfacial polarization resulting from the introduction of Al 2 O 3 . Given prominent oxidation resistance, thermal insulation and EMW absorption properties, the SiBCN/Al 2 O 3 composite aerogel paves the way for developing microwave absorption and thermal insulation integrated material in high-speed vehicles.
研究领域:
材料科学
·
航空航天工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Qi Ding,Jiahao Yang,Shijia Gu,Chutong Chen,Zhi Cheng,Yongping Liu,Peng Yan,Mingming Si,Sijia Lu,Zongbo Zhang,Lianjun Wang,Yuchi Fan,Wan Jiang
Since electromagnetic interference (EMI), icing, and fire incidents greatly threaten aviation safety, multifunctional EMI shielding materials are urgently required in the aviation industry. However, developing highly efficient EMI shielding materials that combine fire resistance and thermal management remains a significant challenge. Here, a novel fire-resistant SiBCN ceramic fiber paper with excellent EMI shielding and Joule heating performance was fabricated via electrospinning followed by cross-linking, pyrolysis, and annealing. Compared with the SiBCN fiber paper prepared at 800 °C with poor EMI shielding performance, the total shielding effectiveness (SE T ) of the SiBCN fiber paper annealed at 1400 °C significantly increased to 21 dB, with specific shielding effectiveness (SSE/t) as high as 3317 dB•cm 2 •g −1 , due to the precipitation of “island-like” conductive turbostratic C, facilitating the synergistic effects of conduction loss, dipole polarization, and interfacial polarization, resulting in high efficiently attenuation of the electromagnetic waves (EMW). Furthermore, the fiber paper demonstrated excellent fire-resistant and Joule-heating performance, with a rapid electrothermal conversion response and a high saturation temperature of 300 °C at 12 V. Therefore, this work proposes a novel strategy for designing multifunctional ceramic fiber paper with integrated EMI shielding, fire resistance, and Joule heating performance for aircraft safety.
研究领域:
材料科学
·
航空工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Xiang Zhang,Zhe Huang,Junpeng Jiang,Yunjia Xue,Liwen Yan,Anran Guo,Feng Hou,Jiachen Liu
Mullite fiber felts with excellent thermal insulation performance are commonly used in thermal protection systems (TPSs) for high-speed vehicles. However, the large pore structure formed by overlapping fibers results in inadequate obstruction of thermal convection and insufficient resilience force, thereby limiting their suitability as thermal sealing materials for the gaps in aircraft moving parts. In this work, a SiBCN aerogel/mullite fiber composite was fabricated via vacuum impregnation and a typical PDC aerogel method to improve the thermal insulation performance and strength of flexible mullite fiber felts. This approach enhances the strength while maintaining the flexibility of the fiber felts. The impact of impregnation times on the evolution of the microstructure, rebound resilience, and thermal insulation performance of the composite was investigated. The nano-pore structured SiBCN aerogels can pad the large pores of mullite fiber felts, resulting in a decrease in the thermal conductivity of the composite from 0.047 W m −1 K −1 to 0.038 W m −1 K −1 . Owing to the integration of adequate resilience and excellent thermal insulation properties, the SiBCN aerogel/mullite fiber composite provides the foundation for thermal sealing materials for aerospace applications.
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 THE EUROPEAN CERAMIC SOCIETY
·
2025
·
IF 6.2
Siyao Chen,Yaoyao Qin,Qiang Yan,Haofan Shi,Yue Gao,Bo Gao,Fan Yang,Xinhao Chen,Jinping Li,Songhe Meng
Due to the excellent piezoresistive properties and high-temperature stability, polymer-derived ceramics (PDCs) have been recognized as promising for sensing. However, enhancing their sensitivity remains challenging yet critical. In this work, a precursor modification strategy is presented and the enhancement in piezoresistive sensing performance of its derived ceramics is quantitatively characterized. The pre-designed hydrosilylation between original precursor and vinyl-contained tetravinylsilane (TVS) allowed the precise regulation of free carbon content and conductive network formation. The polymer-greenbody-ceramic conversion process was monitored, where the resultant ceramic was lightweight (~1.9 g/cm³) and superior thermal stable. It is revealed that pyrolysis temperature and TVS content synergistically govern the graphitization evolution and piezoresistive behavior. The optimized ceramic exhibited a gauge factor of 4181, representing a 46.7% enhancement over the original samples, accompanied by cyclic analyses that confirmed its durability. This study establishes a feasible approach to designing high-sensitivity SiBCN sensors and advances their application through composition-structure-property tailoring.
研究领域:
材料科学
·
陶瓷
·
传感器
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
·
2025
·
IF 8.9
Qihong Wei,Kaili Zhang,Yuefeng Yan,Changtao Shao,Dechang Jia,Xiaoxiao Huang,Yu Zhou
Polymer-derived ceramics (PDCs) have demonstrated significant application potential in the microwave absorption field due to the remarkable high temperature stability, low density and tunable dielectric properties. However, the single PDCs microwave absorption performance is limited due to low dielectric loss ability. In this study, a novel SiBCN/carbon fibers (SiBCN/CF) composite was fabricated using PDCs and mechanical mixing processes. The conductivity, dielectric properties and microwave absorption performance of the SiBCN/CF composite could be controlled by regulating the content of CF. The impedance matching and attenuation property of SiBCN/CF have been improved due to the synergy loss of the conductive network structure of the CF, multiple phase interfaces (BN, Si 3 N 4 and SiC) in the SiBCN ceramic and defects. The experimental results showed that the SiBCN/CF exhibits efficient microwave absorption performance with a filling content of 15 wt%. The minimum reflection loss (RL min ) value is −46.16 dB (2.5 mm), the maximum effective absorption bandwidth (EAB max ) achieves 7.87 GHz (10.13–18 GHz) at 2.39 mm and the radar cross section (RCS) value is 4.18 dB·m 2 at 0°. This research provides a valuable strategy for developing novel lightweight, broadband and strong microwave absorption materials.
研究领域:
材料科学
·
微波工程
·
复合材料技术
·
介电材料
·
电磁吸收
✓ 已验证
产品关联
DOI
高影响因子
CARBON
·
2023
·
IF 10.9
Yin Wang,Chunjia Luo,Yaofeng Wu,Xi Hu,Liuying Wang,Xi Chen,Min Chao,Gu Liu,Yongbiao Hu,Luke Yan
Currently, polymer-derived ceramics (PDCs) often achieve electromagnetic (EM) wave attenuation by in situ generation of nanocrystals . In this paper, amorphous monolithic siliconboron carbonitride (SiBCN) ceramics with outstanding microwave absorption property were prepared via pyrolysis of hyperbranched polyborosilazane crosslinked with divinylbenzene (DVB). The crosslinking of DVB increases the ceramic yield and the sp 2 carbon contents, which facilitates the formation of multiple ordered carbon structures and enhances the dielectric loss and microwave absorption property of ceramics. By regulating DVB content and pyrolysis temperature, the amorphous SiBCN ceramics with ordered carbon structures exhibit optimized microwave absorption performance with a minimum reflection coefficient (RC min ) of −54.24 dB and a maximum effective absorption bandwidth (EAB max ) of 3.15 GHz. Further, when the planar sample is tested using arch method, the practical RC min value is −14.86 dB at 14.46 GHz and the EAB max is up to 6.4 GHz (11.6 GHz–18 GHz). In addition, the amorphous SiBCN has excellent high temperature resistance, no mass change in nitrogen (N 2 ) and only 3.23% mass loss in air until 1400 °C. The high temperature stable, amorphous SiBCN microwave absorption ceramics provide a new strategy to the preparation of microwave absorption materials .
研究领域:
材料科学
·
电磁学
✓ 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）