Wang Wei, You Qi, Wu Zhanwu, Cui Sheng, Shen Weimin
College of Materials Science and Engineering, Nanjing Tech University, Nanjing 210009, China.
Jiangsu Collaborative Innovation Center for Advanced Inorganic Function Composites, Nanjing Tech University, Nanjing 211800, China.
Gels. 2024 Apr 24;10(5):292. doi: 10.3390/gels10050292.
Aerogels, as a new type of high-temperature-resistant insulation material, find extensive application in aerospace, high-temperature industrial furnaces, new energy batteries, and various other domains, yet still face some limitations such as inadequate temperature resistance and pronounced brittleness. In this work, SiC/HfC composite aerogels were prepared through a combination of sol-gel method, atmospheric pressure drying technique, and carbothermal reduction reaction. The effects of different molar ratios, calcination time, and temperatures on the microstructural features and physicochemical properties of the resulting SiC/HfC composite aerogels were investigated. The aerogel exhibited an elevated BET-specific surface area of 279.75 m/g, while the sample displayed an extraordinarily low thermal conductivity of 0.052 W/(m·K). Most notably, the compressive strength reached an outstanding 5.93 MPa after a carbonization temperature of 1500 °C, far exceeding the values reported in prior aerogel studies. This research provided an innovative approach for advancing the development of carbide aerogels in the realm of high-temperature applications.
气凝胶作为一种新型耐高温绝缘材料，在航空航天、高温工业炉、新能源电池等诸多领域有着广泛应用，但仍存在一些局限性，如耐温性不足和脆性明显等问题。在本研究中，通过溶胶 - 凝胶法、常压干燥技术和碳热还原反应相结合的方法制备了SiC/HfC复合气凝胶。研究了不同摩尔比、煅烧时间和温度对所得SiC/HfC复合气凝胶微观结构特征和物理化学性质的影响。该气凝胶的BET比表面积高达279.75 m²/g，而样品的热导率极低，仅为0.052 W/(m·K)。最值得注意的是，在1500℃碳化温度后，抗压强度达到了出色的5.93 MPa，远远超过了先前气凝胶研究报道的值。本研究为推进碳化物气凝胶在高温应用领域的发展提供了一种创新方法。
