Preparation of Sustainable Kapok Fiber/Chitosan Composite Aerogels with Amphiphilic and Mechanical Properties for Thermal Insulation and Packaging Applications

With the growing global scarcity of energy sources, there is an increasing focus on the development of thermal insulation materials. Kapok fiber, a renewable agricultural by-product, garners attention as an eco-friendly thermal insulation material due to its unique hollow structure. Here, we report a fast and simple route to prepare environmentally friendly, economical, and sustainable aerogels. In this study, kapok fiber/chitosan (KF/CS) composite aerogel and its control samples were prepared from kapok fiber and chitosan using wet-laid, soaking, and freeze-drying techniques. Our results demonstrated that alkali-treated kapok fibers exhibited hydrophilicity, which improved their water dispersibility to form a homogeneous and stable aerogel backbone. The samples exhibited excellent oil–water amphiphilicity and UV resistance as well as certain compression recovery, where the oil–water contact angles were below 40 and 50°, respectively. Compared to the unsoaked US-KF control samples, the KF/CS composite aerogels soaked prior to freeze-drying had higher porosity (98.32–98.48%) and thermal resistance (0.072–0.079 m² ℃ w⁻¹) and lower density (0.019–0.022 g/cm³). The current study indicated that the KF/CS composite aerogel is a potential bio-based material with promising applications in the fields of packaging and building insulation.