Abstract Silica aerogel shows great potential in the relevant high-temperature applications, such as furnaces, tubes, and bricks. The related studies on addressing its behaviors under high temperatures are critically needed. Through this study, the effects of heating rate on its high-temperature behaviors of silica aerogel granule with a size of 100 mesh were addressed experimentally, including density, pore size distribution (PSD) and so on. It was known from the experimental results that the skeleton density increases under a relatively higher heating rate, while the densification, shrinkage, and fractional density show a decreasing trend. The mean coordination number of tested silica aerogel was obtained within a range of 2.016–2.034 contacts. The confusing of the primary particle was found mainly occurring at the sample surface for all the tested samples. It was also known that the diameter of the primary particle increases from 44 to 71 nm when the heating rate increases from 5 to 20 °C/min, but for the particle, it shows a decreasing trend. After the heating processes, the pore model of the sample was changed from cylinder to slit-shaped. A fast heating rate was found to promote the transfer from the Si–OH group to the Si–O–Si group.

中文翻译：

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升温速率对二氧化硅气凝胶纳米多孔结构的影响

摘要 二氧化硅气凝胶在相关高温应用中显示出巨大的潜力，如熔炉、管道和砖块。迫切需要解决其在高温下的行为的相关研究。通过本研究，实验探讨了升温速率对100目二氧化硅气凝胶颗粒高温行为的影响，包括密度、孔径分布（PSD）等。由实验结果可知，在较高的加热速率下，骨架密度增加，而致密化、收缩和分密度呈下降趋势。测试二氧化硅气凝胶的平均配位数在 2.016-2.034 接触范围内获得。对于所有测试样品，发现初级颗粒的混淆主要发生在样品表面。还已知当加热速率从 5℃/min 增加到 20℃/min 时，初级粒子的直径从 44 nm 增加到 71 nm，但对于粒子，它显示出减小的趋势。加热过程后，样品的孔隙模型从圆柱体变为狭缝形。发现快速加热速率可促进从 Si-OH 基团向 Si-O-Si 基团的转移。