I-Corps: Sustainable Nanocellulose-based Organic Aerogels for Thermal Insulation Applications

无机气凝胶如二氧化硅、粘土和金属氧化物在过去的70年中得到了广泛的研究。无机气凝胶的一个主要缺点是它们易碎。有机气凝胶通常更具柔性，但其机械模量和强度往往较低。该团队基于纳米原纤化纤维素纤维（NFC）的有机气凝胶的独特之处在于，通过优化材料配方和工艺，它们既灵活又坚固。 与文献中报道的其他类型气凝胶的特定机械性能相比，该团队的聚乙烯醇（PVA）-NFC氧化石墨烯（GO）气凝胶的特定机械性能是有利的。此外，NFC由可持续和丰富的生物质制成，因此使其成为比石油产品更环保的材料。此外，这些基于NFC的气凝胶是使用冷冻干燥工艺制备的，该工艺使用水而不是有机溶剂。冷冻干燥具有允许容易放大的潜力。气凝胶由于其不寻常和令人感兴趣的材料性质而引起了极大的关注，包括高孔隙率（通常为90%至99%）、超低密度、高比表面积和非常低的热导率、热导率和热导率。该团队在实验室中使用环保和可扩展的工艺制造的可持续NFC基气凝胶具有优异的柔韧性和比压强度，极低的导热率和吸水率以及良好的热稳定性。因此，它们可用于广泛的隔热应用，如家庭和建筑物，工业设备和服装。这个I-Corps项目将帮助团队加深对气凝胶密度和材料性能关系的理解，如果成功的话，可以为各种应用的材料选择提供指导。

Inorganic aerogels such as silica, clay, and metal oxide have been extensively studied during the last 70 years. One major disadvantage of inorganic aerogels is that they are brittle. Organic aerogels generally are more flexible, but their mechanical moduli and strengths tend to be lower. The uniqueness of the team's nanofibrillated cellulose fiber (NFC)-based organic aerogels is that with optimized material formulations and processes, they can be both flexible and strong. The specific mechanical properties of the team's polyvinyl alcohol (PVA)-NFCgraphene oxide (GO) aerogels are favorable in comparison with the specific mechanical properties of other types of aerogels reported in the literature. Furthermore, NFCs are made from sustainable and abundant biomass, thus making it a more environmentally friendly material than petroleum-based products. In addition, these NFC-based aerogels are prepared using a freeze-drying process, which uses water instead of organic solvents. Freeze-drying has the potential to allow for easy scale-up. Aerogels have drawn significant attention due to their unusual and interesting material properties, including a high porosity (typically 90% to 99%), ultra-low density, high specific surface area, and very low thermal, acoustic, and electrical conductivities. The sustainable NFC-based aerogels the team fabricates using an environmentally friendly and scalable process in the lab have excellent flexibility and specific compressive strength, extremely low thermal conductivity and water absorption, and good thermal stability. As such, they can be used for a wide range of thermal insulation applications such as homes and buildings, industrial equipment, and clothing. This I-Corps project will help the team deepen their understanding of the aerogel density and material property relationship, which can provide a guideline, if successful, for material selections for various applications.