Abstract：
With the increasing severity of energy shortages and environmental pollution, there is an urgent need for advanced thermal insulation materials with excellent comprehensive performance, including low thermal conductivity, high flame resistance, and strong compressive strength. Herein, an anisotropic composite aerogel based on cellulose nanofibers (CNF), calcium alginate (CA), and boric acid (BA) is fabricated using a directional freeze-drying strategy. The CA and BA, as double cross-linking agents, associated with oriented porous structure provide the resultant aerogel with good mechanical strength. Additionally, self-flame retardant CA and BA act as synergistic flame retardants that endow the aerogel with excellent flame retardance properties such as a limiting oxygen index value of 44.2 %, UL-94 V-0 rating, and low heat release. Furthermore, this composite aerogel exhibits outstanding thermal insulation performance with a low thermal conductivity of approximately 30 mW m-1 K-1. Therefore, the composite aerogel is expected to have a wide potential application in areas such as construction, automotive industry, batteries, petrochemical pipelines, and high-temperature reaction devices.
摘要：
随着能源短缺和环境污染的日益严重,迫切需要综合性能优异的先进保温材料，包括低热导率，高阻燃性,和强大的抗压强度。在这里，基于纤维素纳米纤维（CNF）的各向异性复合气凝胶，海藻酸钙（CA），和硼酸（BA）是使用定向冷冻干燥策略制备的。CA和BA，作为双交联剂，与定向多孔结构相关的气凝胶提供了良好的机械强度。此外,自阻燃CA和BA作为协同阻燃剂，赋予气凝胶优异的阻燃性能，如44.2％的极限氧指数值，UL-94V-0等级,和低热量释放。此外，这种复合气凝胶具有出色的隔热性能，导热系数约为30mWm-1K-1。因此,复合气凝胶有望在建筑等领域具有广泛的潜在应用，汽车行业,电池,石化管道，和高温反应装置。
