材料科学
保温
热的
结构材料
纳米线
透明度(行为)
工程物理
纳米技术
复合材料
热力学
物理
图层(电子)
政治学
法学
作者
Wei Zhang,Lei Su,De Lu,Kang Peng,Min Niu,Lei Zhuang,Jian Feng,Hongjie Wang
标识
DOI:10.26599/jac.2023.9220813
摘要
With the development of aerospace technology, the Mach number of aircraft continues to increase, which puts forward higher performance requirements for high-temperature wave-transparent materials. Silicon nitride has excellent mechanical properties, high-temperature stability, and oxidation resistance, but its brittleness and high dielectric constant impede its practical applications. Herein, by employing a template-assisted precursor pyrolysis method, we prepared a class of Si3N4@SiO2 nanowires aerogels (Si3N4@SiO2 NWAGs) that are assembled by Si3N4@SiO2 nanowires with diameters ranging from 386 nm to 631 nm. The Si3N4@SiO2 NWAGs have low densities (12-31 mg·cm-3), a specific surface aerogel of 4.13 m2g-1, and an average pore size of 68.9 μm. Mechanical properties characterization shows that the aerogels exhibit reversible compressibility from 60% compressive strain and good fatigue resistance even when being compressed for 100 times at a set strain of 20%. The aerogels also show good thermal insulation performance (0.032 W·m-1K-1 at room temperature), ablation resistance (butane blow torch), and high-temperature stability (maximum service temperature in the air over 1200 °C). The dielectric constant and loss of the aerogels are 1.02-1.06 and 4.3× 10-5-1.4×10-3 at room temperature, respectively. The combination of the good mechanical, thermal, and dielectric properties makes Si3N4@SiO2 NWAG a promising ultralight wave-transparent and thermally insulating material for application at high temperatures.
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