Kriechbaum Konstantin, Apostolopoulou-Kalkavoura Varvara, Munier Pierre, Bergström Lennart
Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, Svante Arrhenius väg 16 C, 106 91 Stockholm, Sweden.
ACS Sustain Chem Eng. 2020 Nov 30;8(47):17408-17416. doi: 10.1021/acssuschemeng.0c05601. Epub 2020 Nov 13.
Thermally insulating foams and aerogels based on cellulose nanofibrils (CNFs) are promising alternatives to fossil-based thermal insulation materials. We demonstrate a scalable route for moisture-resilient lightweight foams that relies on sclerotization-inspired Michael-type cross-linking of amine-modified CNFs by oxidized tannic acid. The solvent-exchanged, ice-templated, and quinone-tanned cross-linked anisotropic structures were mechanically stable and could withstand evaporative drying with minimal structural change. The low-density (7.7 kg m) cross-linked anisotropic foams were moisture-resilient and displayed a compressive modulus of 90 kPa at 98% relative humidity (RH) and thermal conductivity values close to that of air between 20 and 80% RH at room temperature. Sclerotization-inspired cross-linking of biobased foams offers an energy-efficient and scalable route to produce sustainable and moisture-resilient lightweight materials.
基于纤维素纳米纤维（CNF）的隔热泡沫和气凝胶是化石基隔热材料的有前途的替代品。我们展示了一种用于制备防潮轻质泡沫的可扩展方法，该方法依赖于受硬化启发的胺改性CNF与氧化单宁酸的迈克尔型交联。经溶剂交换、冰模板化和醌鞣交联的各向异性结构具有机械稳定性，并且能够承受蒸发干燥，结构变化最小。低密度（7.7 kg/m³）的交联各向异性泡沫具有防潮性，在98%相对湿度（RH）下的压缩模量为90 kPa，在室温下20%至80% RH之间的热导率值接近空气。受硬化启发的生物基泡沫交联提供了一种节能且可扩展的途径，以生产可持续且防潮的轻质材料。
