In-situ acid catalysis strategy to achieve rapid ambient pressure drying preparation of aerogels

Abstract

Aerogel possesses distinctive features rendering it widely applicable in thermal insulation. Nevertheless, supercritical fluid drying (SCFD) method and freeze-drying employed for aerogels necessitates the complex process, resulting in heightened energy consumption and more risk. To achieve the cost-effective preparation of silica aerogel, we introduce an in-situ acid catalysis strategy for rapidly crafting high-performance SiO₂ aerogel materials under ambient conditions. The resultant SiO₂ aerogels exhibit remarkable porosity (95%) and a substantial specific surface area (759 m²/g). Furthermore, SiO₂ aerogel composites display low thermal conductivity (0.015 W·m⁻¹ K⁻¹), coupled with commendable mechanical property. More importantly, we reveal the mechanism of the in-situ acid catalysis (ISAC) strategy. The entire production cycle of SiO₂ aerogel composites and powder is only 6 and 4 h respectively, which greatly reduces the preparation time while ensuring excellent performances. This study introduces a novel approach for the industrial, low-cost, and rapid preparation of SiO₂ aerogel materials through ambient pressure drying.

Graphical Abstract