Preparation and Characterization of Clay Aerogel Composites Reinforced by Calcium Sulfate Whisker

Clay aerogel has attracted much interests for potential applications such as aerospace, industry, and construction owing to its low density, high porosity, and large specific surface area. However, the application of clay aerogel is limited owing to their high fragility. In this study, calcium sulfate whisker (CSW) was employed to improve the mechanical properties of montmorillonite (MMT)-based clay aerogel through a simple environmentally friendly freeze-drying method. The CSW/clay aerogel composites were characterized by SEM, TGA, compression and thermal conductivity measurement. The experimental results showed that the addition of CSW could significantly change the microstructure, vastly enhance the mechanical properties, and slightly improve thermal insulation of the resultant CSW/clay aerogel composites. Particularly, compared with the neat clay aerogel, the best sample of CSW/clay aerogel composites presented an increased modulus by approximately 200% and a decreased thermal conductivity by approximately 14%.