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年里得到了广泛的研究。无机气凝胶的一个主要缺点是易碎。有机气凝胶通常更灵活，但其机械模量和强度往往较低。该团队基于纳米纤原纤维素纤维（NFC）的有机气凝胶的独特之处在于，通过优化的材料配方和工艺，它们可以既灵活又坚固。与文献中报道的其他类型的气凝胶相比，该团队的聚乙烯醇(PVA)- nffc氧化石墨烯（GO）气凝胶的特定机械性能是有利的。此外，nfc是由可持续和丰富的生物质制成的，因此它比石油基产品更环保。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。冷冻干燥有可能使扩大规模变得容易。气凝胶因其独特而有趣的材料特性而备受关注，包括高孔隙率（通常为90%至99%）、超低密度、高比表面积，以及非常低的导热性、声学导电性和导电性。该团队在实验室中使用环保和可扩展的工艺制造了基于nfc的可持续气凝胶，具有出色的柔韧性和比抗压强度，极低的导热性和吸水性，以及良好的热稳定性。因此，它们可以用于广泛的隔热应用，如家庭和建筑物，工业设备和服装。I-Corps项目将帮助团队加深对气凝胶密度和材料性质关系的理解，如果成功，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.