PDF(Pubmed)
Abstract：
Silica aerogels are highly porous materials with exceptional thermal insulation performance. They become even more attractive if combined thermal and acoustic insulation is achieved. Silica aerogel composites reinforced with fibres are an ingenious way to surpass the fragility stemmed from the aerogel\'s intrinsic porosity, and textile fibres are good sound absorption materials. Reclaimed fibres are a relatively low-cost feedstock and were obtained in this work exclusively through mechanical processes from textile wastes, thus promoting the concept of circular economy, namely for cotton, polyester and wool fibres. These reclaimed fibres were used as reinforcement matrices for silica aerogel composites obtained from sol-gel transformation of tetraethyl orthosilicate and isobutyltriethoxysilane/or vinyltrimethoxysilane precursors and dried at ambient pressure after silylation. Silica aerogel composites reinforced with reclaimed cotton fibres had the best sound absorption coefficient (a peak value of 0.89), while the polyester-reinforced composite exhibited the lowest thermal conductivity (k = ~24 mW m-1 K-1, Hot Disk). The better combined results on thermal and acoustic insulation were achieved by the wool-reinforced composites. The thermal conductivity values were less than 27 mW m-1 K-1, and the sound absorption coefficient achieved a peak value of 0.85. Therefore, the aerogel composites developed here can be selected for thermal or/and acoustic barriers by choosing a suitable type of fibre. Their design and preparation protocol followed environmental-friendly and cost-effective approaches.
摘要：
二氧化硅气凝胶是高度多孔材料，具有出色的隔热性能。如果实现组合的隔热和隔音,则它们变得甚至更有吸引力。用纤维增强的二氧化硅气凝胶复合材料是一种巧妙的方法，可以超越气凝胶固有孔隙率造成的脆性，和纺织纤维是良好的吸声材料。再生纤维是一种相对低成本的原料，在这项工作中完全是通过纺织废物的机械工艺获得的，从而推广循环经济的概念，即棉花，聚酯和羊毛纤维。这些再生纤维用作增强基质，用于通过原硅酸四乙酯和异丁基三乙氧基硅烷/或乙烯基三甲氧基硅烷前体的溶胶-凝胶转化获得的二氧化硅气凝胶复合材料，并在甲硅烷基化后在环境压力下干燥。用再生棉纤维增强的二氧化硅气凝胶复合材料具有最佳的吸声系数（峰值为0.89），而聚酯增强的复合材料表现出最低的热导率（k=〜24mWm-1K-1，热盘）。羊毛增强复合材料在隔热和隔音方面取得了更好的综合效果。热导率值小于27mWm-1K-1，吸声系数达到0.85的峰值。因此,可以通过选择合适类型的纤维来选择本文开发的气凝胶复合材料用于热和/和声屏障。他们的设计和准备方案遵循环保和具有成本效益的方法。
