JOURNAL OF MATERIALS SCIENCE
·
2018
·Vol. 53
·期 19
·13573-13583
·
IF 2.993
Huang Zhifeng,Wang Zhihao,Yuan Hailong,Zhang Jianwen,Chen Fei,Shen Qiang,Zhang Lianmeng
In this work, Y-, Ce- and Tb-doped Si 3 N 4 nanowires have been successfully synthesized by directly nitriding-doped nanocrystalline silicon powders obtained by cryomilling. The obtained single-crystalline α-Si 3 N 4 nanowires are nearly 20–50 nm in diameter and up to several micrometers in length. The photoluminescence properties of doped Si 3 N 4 nanowires have also been investigated. The Y-doped Si 3 N 4 nanowires exhibit the main peak at 425 nm, Ce-doped Si 3 N 4 nanowires show a narrow emission peak at 450 nm, and Tb-doped Si 3 N 4 nanowires present a strong and sharp emission peak at 545 nm. Combining with our previous works on Al-, La- and Eu-doped Si 3 N 4 nanowires, the effects of dopants with different valence electron configurations on the photoluminescence properties have been explored. The present study provides a guide to fabricate Si 3 N 4 -based nanomaterials for different photonic applications.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2024
·
IF 10.7
Mengyi Li,Baokai Wang,Chang Yu,Mengyang Niu,Kunjie Yuan,Weiwei Xuan,Ming Yue,Lifeng Zhu,Kexin Chen,Qi Wang
With great advancements in foldable electronic devices, there has been growing interest in ultra-light and flexible composite films possessing high in-plane thermal conductivity. One-dimensional (1D) Si3N4 nanowires (Si3N4NWs) possess the advantages of high thermal conductivity, superior mechanical performance and easy to be directionally aligned to construct thermally conductive pathways, which have been considered one of the ideal fillers for preparing anisotropic composite films. However, 1D Si3N4NWs with high aspect ratios tend to aggregate and are difficult to be dispersed in polymer matrixes, while traditional dispersion approaches utilizing prolonged ball milling or strong mechanical mixing easily result in a significant reduction in the length of Si3N4NWs, making it difficult to fully exploit the advantages of high intrinsic thermal conductivity. Therefore, it is highly essential to prepare high-performance composite films without damaging the length of Si3N4NWs. In this study, we propose an innovative strategy for the direct construction of continuous thermally conductive networks composed of ultra-long Si3N4NWs. An entire piece of Si3N4NW paper was successfully synthesized, which was directly used to prepare composite films via a simple vacuum-impregnation combined with hot-pressing method. Since the high aspect ratio of Si3N4NWs was maximally preserved during the composite process, the prepared Si3N4NW/EP composite films exhibited a high in-plane thermal conductivity of 16.02 W m−1 K−1 at a filling fraction of 64.6 wt%. More importantly, the interconnected, ultra-long Si3N4NWs also provide composite films with flexibility and excellent mechanical strength, enabling promising applications in the thermal management of electronic devices.
研究领域:
材料科学
·
纳米技术
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
International Journal of Applied Ceramic Technology
·
2019
·Vol. 16
·期 6
·2173-2180
·
IF 1.074
Ming-Ye Yang,Bin-Bin Dong,Fei-Hong Wang,Xin Xu,Simeon Agathopoulos
This paper reports on the successful fabrication of α -Si 3 N 4 -nanowire/Y 2 Si 2 O 7 composite membranes with superhydrophobic properties, aiming to achieve a high performance in membrane distillation. The starting powder mixture of 87 wt% γ -Y 2 Si 2 O 7 , 5 wt% Si, 3 wt% LiYO 2 , and 5 wt% ferrocene catalyst was dispersed in a stable suspension, and after being tape-casted, it was sintered at 1300°C for 4 hours in order to obtain the composite membrane. α -Si 3 N 4 nanowires with a diameter of about 50 nm were formed, distributed uniformly on the surface and in the pores of the membrane and their presence greatly favored superhydrophobicity. After surface modification with a robust hydrophobic layer of SiNCO nanoparticles, strongly adhered to the surface of the produced membrane, a water contact angle of 153 o , was measured. Water desalination experiments, using a sweeping gas membrane distillation (SGMD) device, were conducted. High water flux of 11.91 L/m 2 /h was achieved for a 4 wt% NaCl feeding solution at 90°C. Stable water flux and rejection rates were recorded in long-term experiments (>500 hours) using the produced superhydrophobic composite membrane.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Guanjie Zeng,Xin Li,Yanjing Wei,Tong Guo,Xiaozhong Huang,Xuelong Chen,Xiu-Zhi Tang
Porous ceramic materials with high electromagnetic absorption capacity, low density, high thermal resistance and excellent mechanical properties are highly desirable in aerospace applications. Here, we synthesized one type of hierarchical SiC composite foams with in situ grown Si 3 N 4 nanowires via a pyrolysis process. The existence and structure of Si 3 N 4 nanowires were characterized by multiple techniques and analysis revealed that the growth of nanowires was based on a typical vapor-solid mechanism. Owing to the presence of a large amount of Si 3 N 4 nanowires, both the mechanical performance and electromagnetic absorption were significantly enhanced. The minimum Reflection loss (RL) of 1.25 mm SiC composite foam reaches −50.3 dB at 16.48 GHz with an effective bandwidth (RL < −10 dB) of 3.6 GHz (14.4–18 GHz), while the toughness and specific compressive strength increased by 356% and 126%, respectively. Especially, a ductile and steady fracture behavior was observed for the mechanically enhanced composite foam, rather than the typical catastrophic failure usually seen for ceramic materials. Owing to the excellent electromagnetic wave absorption capability and enhanced mechanical properties, as well as low density and high thermal resistance, this type of composite ceramic material may find applications in aviation, aerospace and other extreme environments.
研究领域:
材料科学
·
航空航天工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）