Journal of Materials Chemistry A
·
2024
·
IF 10.7
Ruyue Su,Jingyi Chen,Xueqin Zhang,Wenqing Wang,Rujie He,Ying Li
Terahertz (THz) electromagnetic interference (EMI) shielding materials with superior performance are urgently needed with the development of THz electronic devices. Herein, a photocured Ti3C2Tx MXene/SiOC ceramic (MSiOC) composite with a sandwich-like structure was prepared using a photosensitive resin as a precursor. In addition, the EMI shielding properties of the MSiOC composite with a low mass loading of the MXene were greatly improved. The influence of the content of Ti3C2Tx MXenes on the EMI shielding properties of the MSiOC composite was studied, and its EMI shielding mechanism was further elucidated. The resultant MSiOC composite exhibited an average shielding effectiveness (SET) of 24.5 dB in the frequency range of 0.2–1.6 THz at a MXene mass loading of only 0.3 wt%, which was remarkably improved by 53% compared to pure SiOC. In addition, the MSiOC composite with a broad high-absorptivity frequency band showed an absorption-dominated THz EMI shielding mechanism. This result proved that the synergistic effect of the MXene and SiOC was responsible for the high attenuation capability of MSiOC for THz waves. Finally, MSiOC with customized structures was easily fabricated via vat photopolymerization 3D printing, followed by a pyrolysis process. The smallest feature size of these structures was about 140 μm. Moreover, the flexible photocured green part could be secondary molded, which improved the structural controllability of the composite. Our work provides insights into the rational design of MXene-based composites for new-generation THz EMI shielding 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
Additive Manufacturing
·
2025
·
IF 11.1
Cunxian Wang,Haodong Wang,Lu Tang,Jimei Xue,Zhijun Wang,Hanjun Wei
Microwave absorbing structures are important for addressing challenges in complex electromagnetic (EM) and physical environments because they offer broadband absorption, a lightweight design, and mechanical load-bearing capabilities. Herein, this work employed vat photopolymerization 3D printing and polymer-derived ceramics (PDCs) technology to manufacture Re 2 O 3 -modified SiOC metamaterials, where Re refers to holmium (Ho), neodymium (Nd), and yttrium (Y). The materials feature a triply periodic minimal surface (TPMS) meta-structure inspired by the gyroid structure. The effects of different Re elements on the dielectric, magnetic, microwave absorption, and compression properties were investigated. Compared with the original SiOC, Ho 2 O 3 SiOC, and Y 2 O 3 SiOC ceramics, the Nd 2 O 3 SiOC ceramic demonstrated excellent absorption characteristics within the X band. It achieves a minimum reflection loss (RL min ) of 45.12 dB at 4.15 mm and an effective absorption bandwidth (EAB) spanning 4.2 GHz from 3.5 to 3.7 mm. This performance is attributed mainly to the TPMS meta-structure, which improves impedance matching. The Nd 2 O 3 particles enhance the dielectric and magnetic losses. The Nd 2 O 3 SiOC ceramic also demonstrated strong mechanical properties, with a maximum failure strength of 11.3 MPa and a Young’s modulus of 1.72 GPa. These results arise from the uniform dispersion and fine-scale distribution of Nd 2 O 3 within the SiOC matrix. The CST simulations indicate that the Nd 2 O 3 SiOC metamaterials cover the entire C-band (4–8.2 GHz), which is particularly effective within thicknesses ranging from 2.9 to 5.0 mm. Consequently, Nd 2 O 3 SiOC ceramics display substantial promise in both their low-frequency and broadband absorption capabilities, as well as in their mechanical load-bearing properties.
研究领域:
材料科学
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电磁学
·
结构工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2024
·
IF 5.8
Qi You,Zhongyang Wu,Yongjun Li,Ya Zhong,Sisi Shang,Man Yuan,Yichen Ou,Huanhuan Xu,Sheng Cui
Mullite aerogel is considered a promising candidate for thermal protection. However, structural collapse and poor temperature resistance limit its application at high temperature. Herein, amorphous SiOC-coated mullite aerogels (MAs) were prepared by high-temperature calcination, using Al 2 O 3 nanorods and SiO 2 particles as precursor units. The one-dimensional submicron skeleton prevents weak pearl chain connections and high surface energy, while the nanoscale amorphous SiOC layer protects the encapsulated mullite skeleton, ensuring a strong skeleton and pores at high temperatures. MAs exhibit a low thermal conductivity of 0.0375 W/(m·K) at room temperature, a robust compressive strength of 0.369 MPa, and good thermal stability: after 30 min of annealing at 1500 ℃, the minimal linear shrinkage of MAs was 0.72 %. Interestingly, the amorphous SiOC layer grew into nanowires under a butane flame, which reconstructed the network and impeded the heat flow. Thus, the novel MAs exhibit considerable thermal insulation advantages in harsh environments.
研究领域:
材料科学
·
热防护技术
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2019
·Vol. 9
·期 53
·30685-30692
·
IF 3.049
Sifan Zeng,Wanlin Feng,Shuyuan Peng,Zhen Teng,Chen Chen,Haibin Zhang,Shuming Peng
Multi-functional carbon fiber (CF) based composites have great potential as new-type microwave absorption materials (MAMs). However, it was still a huge challenge to integrate antioxidation and MA properties into CF based composites. Herein, the SiOC ceramics coating modified carbon fibers (SiOC/CFs) were prepared by a polymer precursor pyrolysis method. The X-ray photoelectron spectroscopy (XPS) revealed that the SiOC coating was composed of SiOC, SiO2, and amorphous carbon phases. The SiOC ceramics as dual-functional coating not only heightened the oxidation temperature from 415 °C to 890 °C, but also highly improved the microwave absorbing ability from −12.60 dB to −47.50 dB. The enhanced MA performance could be attributed to multiple reflections in the cross-linked structure, various polarization relaxation processes, and the favorable impedance matching effect. The SiOC ceramics coating as a semiconductor could suppress the skin effect originating from the cross-linked CF network, thus leading to a favorable impedance matching behavior.
研究领域:
材料科学
·
电磁学
✓ 已验证
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2023
·
IF 5.7
Pei Feng,Hanjun Wei,Jimei Xue,Yuhua Shi,Peng Shang,Wenyuan Zhang,Sihai Luo,Xiaoqing Liang,Weifeng He
A designed conductive nanoheterogeneous structure can boost interfacial polarisation and effectively enhance the wave absorption properties. Herein, maze-shaped nanoheterogeneous TiB 2 -SiCnws-SiOC ceramics were synthesised via a polymer-derived ceramics (PDCs) approach for constructing a three-dimensional reticular structure. The addition of TiB 2 not only compensates for the lower conductivity, but also facilitates the growth of curved SiCnws. The results show that the addition of 20 wt% TiB 2 leads to favourable microwave absorption performance, with a minimal reflection coefficient of − 55.1 dB at 8.9 GHz and an effective absorption bandwidth of 4.2 GHz. This can be ascribed to the synergistic effect among polarisation loss, conduction loss, and microwave multiple reflection and scattering due to the unique structure. This study may contribute towards establishing multi-loss mechanisms and controllable dielectric properties in PDCs.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Yalan Miao,Guantong Wang,Hongyu Gong,Mingming Sheng,Jie Jing,Junbin Lu,Maoyun Liu
SiOC ceramics have been considered one of the most promising materials in the field of microwave absorbing materials. When SiOC ceramics are prepared by polymer precursor conversion, chemical modification to improve microwave absorption performance is generally carried out in the precursor preparation and molding process. To meet the requirements of more application scenarios, direct ink writing , one of the 3D printing technologies with more flexible structure and shape design is used to replace the traditional molding methods. In this study, the key problems of the combination of direct ink writing and polymer precursor conversion were solved, and SiOC microwave absorbing ceramics with good structure and shape were obtained. After testing, the minimum reflection loss of the ceramics can reach −36 dB, and the corresponding effective absorption band bandwidth is 2 GHz. The experiments confirmed the possibility of combining 3D printing with polymer precursor conversion and its great potential for preparing microwave absorbing ceramics.
研究领域:
材料科学
·
陶瓷工程
·
增材制造
·
电磁材料
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Wei Gao,Yongzheng Zhang,Yanli Wang,Liang Zhan
The carbon/phenolic composites are extensively considered as an efficient ablative thermal protection material, but inferior oxidation-ablation resistance has limited their further application. In this work, a multiscale ZrO 2 -SiOC coated carbon/phenolic composite (NCF/ZSAx-PA) was fabricated through a dual-stage construction strategy. The as-prepared composites exhibited a low density (0.314–0.348 g/cm 3 ), low thermal conductivity (0.0605–0.0725 W/(m·k)) and promoted compressive strength (2.95/5.08 MPa in the Z/XY direction). Benefiting from the formation of a protective ZrO 2 -SiO 2 ceramic coating, the multiscale composites showed excellent anti-oxidation and ablation performance. The residual weight of NCF/ZSAx-PA was 19.41 % at 1000 °C while the unmodified carbon/phenolic composites were entirely burnt off under an air atmosphere. Besides, the NCF/ZSAx-PA exhibited low back temperature (53.6 °C), low linear ablation rate (0.0519 mm/s), and low mass loss rate (0.0100 g/s) under the 3.62 MW/m 2 oxyacetylene assessment. All the superior properties enabled the NCF/ZSAx-PA a prospective application on the thermal protection system.
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
·
2021
·
IF 4.527
Zongwei Tong,Bixin Yan,Baojie Zhang,Hui Xu,Xiaolei Li,Huiming Ji
Generally, SiOC aerogels are prepared utilizing the high-temperature pyrolysis of polyorganosiloxanes or polycarboorganosilanes in an inert gas atmosphere. However, the crosslinking and drying of the precursor rely on the catalysts of noble metal, the equipment of autoclave, and the technology of supercritical drying, which limit the batch production of SiOC aerogel. In this work, the SiOC aerogels were prepared via pyrolysis of methyltrimethoxysilane/triethoxyvinylsilane (MTMS/VTES) organosilane aerogel precursor (O-SAP), which was synthesized using sol-gel method and ambient pressure drying technology. Under the temperature of 1500 °C, the SiOC aerogel exhibited excellent properties with high porosity (80%), high compressive strength (11.52 MPa), and low thermal conductivity (0.08 W m K −1 ), which overweighed most state-of-the-art SiOC aerogels. More significantly, a new concept of “gases truing” was firstly proposed to explain the microstructure evolution of O-SAP during pyrolysis. This paper is expected to provide insights for the preparation of high-performance SiOC aerogels, with promising applications in heat insulation and anode material of Li-ion battery.
研究领域:
材料科学
·
能源工程
✓ 已验证
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2025
·
IF 3.8
Yang Bai,Yantao Zhang,Junbin Lu,Mingming Sheng,Jie Jing,Haoyu Fang,Yijie Zhou,Hongyu Gong
The concept of producing structure–function integrated wave-absorbing ceramics by combining three-dimensional (3D) printing with the precursor conversion method has sparked extensive discussion and research. However, the synergistic enhancement of both the mechanical and electromagnetic (EM) properties of structural wave-absorbing ceramics remains an area requiring further exploration. In this study, we employed the direct ink writing (DIW) process and polymer-derived ceramics (PDCs) method to fabricate SiOC/SiCN composites with excellent mechanical and EM properties, modified by the polymer infiltration pyrolysis (PIP) process. The results demonstrated that PIP significantly improved the mechanical properties of SiOC/SiCN composites. After one cycle of infiltration pyrolysis, the compressive strength of the material was 6.3 times that of the unmodified state, and after three cycles, the compressive strength reached 10.13 MPa, which was 12.8 times that of the original. Furthermore, after three cycles of infiltration pyrolysis, the material exhibited effective absorption across the entire X-band range (8.2–12.4 GHz) for thicknesses of 4.0 mm and 4.5 mm, with a minimum reflection loss (RL min ) of −64 dB, showcasing excellent wave-absorbing capabilities. This study provides an innovative solution for the synergistic enhancement of both mechanical and EM properties in structure–function integrated wave-absorbing ceramics.
研究领域:
材料科学
·
电磁学
·
制造技术
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Xiao Lin,Zhongyu Long,Long Jiang,Zhiyuan Liu,Changyong Liu,Zhangwei Chen
High-performance SiOC(Fe) wave-absorbing ceramics, containing a large number of carbon nanowires, were successfully prepared using a combination of photopolymerization 3D printing technology and the polymer-derived ceramic pyrolysis method. By employing an optimized segmented slow heating scheme with extended holding time, the pyrolysis of SiOC(Fe) ceramics at 1000 °C facilitated the growth of carbon nanowires, Fe 3 C and SiO 2 grains. These carbon nanowires were interlaced and interconnected within the samples, forming abundant conductive networks. This highly conducive network efficiently converted electromagnetic energy into thermal energy, effectively dissipating electromagnetic waves, and consequently enhancing the microwave absorption performance of ceramics. Moreover, this approach not only reduced ceramic cracks but also improved the dielectric loss performance of the materials, achieving a minimum reflectivity value of −35.72 dB. The SiOC(Fe) ceramics added with 5 wt% VcFe effectively enhanced the magnetic loss of the material, reduced the difference between the relative complex permeability (μ r ) and the relative complex dielectric constant (ε r ), and improved the impedance matching between the material surface and air, thereby further improving its microwave absorption performance. This resulted in an increase in the maximum effective absorption bandwidth of the material to 12.7 GHz at 5 mm. This study offers a promising solution for the preparation of ceramic matrix composite materials incorporating carbon nanowires, magnetic particles and ceramic precursors, which would be potentially valuable for radar detection and sensor applications .
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
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2016
·Vol. 99
·期 8
·2615-2624
·
IF 2.787
Zhaoju Yu,Pei Zhang,Yao Feng,Shuang Li,Yaxing Pei
We present a template-free synthesis of Fe 3 O 4 /SiOC(H) nanocomposites with in situ formed Fe 3 O 4 nanoparticles with a size of about 50 nm embedded in a nanoporous SiOC(H) matrix obtained via a polymer-derived ceramic route. Firstly, a single-source precursor (SSP) was synthesized by the reaction of allylhydridopolycarbosilane (AHPCS) with Fe-acetylacetonate [Fe(acac) 3 ] at 140°C. The SSP was heat-treated at 170°C to generate Fe 3 O 4 nanocrystals in the cross-linked polymeric matrix. Subsequently, the SSP was pyrolyzed at 600°C–700°C in argon atmosphere to yield porous Fe 3 O 4 /SiOC(H) nanocomposites with the high BET surface area up to 390 m 2 /g, a high micropore surface area of 301 m 2 /g, and a high micropore volume of 0.142 cm 3 /g. The Fe-free SiOC(H) ceramic matrix derived from original AHPCS is nonporous. The in situ formation of Fe 3 O 4 nanoparticles embedded homogeneously within a nanoporous SiOC(H) matrix shows significantly enhanced catalytic degradation of xylene orange in aqueous solution with H 2 O 2 as oxidant as compared with pure commercial Fe 3 O 4 nanoparticles.
研究领域:
材料科学
·
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Jianhao Zhang,Quan Li,Yi Jia,Li Sun,Yang Wang,Sheng Cui,Jian Yang
Developing radar-infrared-compatible stealth materials is challenging because the material performance requirements between infrared and radar stealth are contradictory. At present, ceramic aerogel is one of the candidate materials that may solve this problem. Here, polymer derived SiC/SiOC aerogels were prepared and their microstructures were tailored by annealing temperature. It is found that the synergistic effects of the pore size distribution, the formation of nano-turbostratic carbons (NTCs) network and the content of SiC nanoparticles contribute to the excellent electromagnetic wave absorption and improved infrared stealth performance of SiC/SiOC aerogel. When the thickness of SiC/SiOC aerogel is 1.78 mm, the minimum reflection loss is -53.5 dB and the maximum effective absorption bandwidth is 6 GHz. In addition, SiC/SiOC aerogel exhibits excellent thermal insulation properties and improved low infrared emissivity. This study provides insights for the development of materials with radar-infrared-compatible stealth properties.
研究领域:
材料科学
·
隐身技术
✓ 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）