Hadi Seyed Ehsan, Yeprem H Aygül, Åhl Agnes, Morsali Mohammad, Kapuscinski Martin, Kriechbaum Konstantin, Sipponen Mika H, Bergström Lennart
Department of Materials and Environmental Chemistry, Stockholm University Stockholm 10691 Sweden
Wallenberg Wood Science Center, Department of Materials and Environmental Chemistry, Stockholm University Stockholm 10691 Sweden.
RSC Adv. 2023 May 9;13(20):13919-13927. doi: 10.1039/d3ra01896b. eCollection 2023 May 2.
Lightweight iron oxide nanoparticle (IONP)/TEMPO-oxidized cellulose nanofibril (TOCNF) hybrid foams with an anisotropic structure and a high IONP content were produced using magnetic field-enhanced unidirectional ice-templating. Coating the IONP with tannic acid (TA) improved the processability, the mechanical performance, and the thermal stability of the hybrid foams. Increasing the IONP content (and density) increased the Young's modulus and toughness probed in compression, and hybrid foams with the highest IONP content were relatively flexible and could recover 14% axial compression. Application of a magnetic field in the freezing direction resulted in the formation of IONP chains that decorated the foam walls and the foams displayed a higher magnetization saturation, remanence, and coercivity compared to the ice-templated hybrid foams. The hybrid foam with an IONP content of 87% displayed a saturation magnetization of 83.2 emu g, which is 95% of the value for bulk magnetite. Highly magnetic hybrid foams are of potential interest for environmental remediation, energy storage, and electromagnetic interference shielding.
采用磁场增强单向冷冻模板法制备了具有各向异性结构和高铁离子氧化物纳米颗粒（IONP）含量的轻质IONP/2,2,6,6-四甲基哌啶氧化物氧化纤维素纳米纤丝（TOCNF）复合泡沫材料。用单宁酸（TA）包覆IONP可改善复合泡沫材料的加工性能、力学性能和热稳定性。增加IONP含量（和密度）可提高压缩试验中测得的杨氏模量和韧性，且IONP含量最高的复合泡沫材料相对柔韧，可恢复14%的轴向压缩。在冷冻方向施加磁场会导致IONP链形成，这些链装饰在泡沫壁上，与冷冻模板复合泡沫材料相比，该泡沫材料具有更高的饱和磁化强度、剩磁和矫顽力。IONP含量为87%的复合泡沫材料的饱和磁化强度为83.2 emu/g，为块状磁铁矿该值的95%。高磁性复合泡沫材料在环境修复、能量存储和电磁干扰屏蔽方面具有潜在应用价值。
