Composite aramid aerogels with anisotropic layered structure reinforced by tetra-needle-like ZnO whiskers for acoustic and thermal insulations
摘要
High-performance and multifunctional aerogels are a new generation of materials that meet modern needs in areas such as thermal and acoustic insulation, but creating the aerogels with a combination of excellent acoustic performance, good thermal conductivity, and mechanical properties is a great challenge, as these properties often have conflicting structural requirements. In this work, T-ZnOw/ANFs composite emulsion containing a large number of air bubbles is prepared by using aramid fibers as the base material, inspired by the microfoam molding process and through the addition of tetra-needle-like ZnO whiskers (T-ZnOw) with a special three-dimensional tetra-needle structure, and the composite emulsion is rapidly frozen in liquid nitrogen to prepare composite aerogels (T-ANFs) with a well-arranged, layered structure inside. The T-ANFs prepared by this process have excellent performance, and its special internal structure enables it to maintain low density and high porosity while possessing robust mechanical properties (compressive stress of 169.9 kPa at 80% strain), excellent multidimensional acoustic performance (NRC of 0.44), and low thermal conductivity (thermal conductivity down to 0.03 W (m ∗ K)−1). Overall, the T-ANFs prepared in this work have great potential for practical applications and possess a wide range of application prospects.