Nanotechnology and Functional Materials, Department of Engineering Sciences, Ångström Laboratory, Uppsala University, 751 21, Uppsala, Sweden.
Chemistry. 2019 Mar 7;25(14):3515-3520. doi: 10.1002/chem.201806417. Epub 2019 Feb 12.
Freestanding nanopapers were fabricated by the assembly of metal-organic frameworks (MOFs) onto cellulose nanofibers (CNFs). The CNFs are wrapped by continuously nucleated MOF layers (CNF@MOF) by interfacial synthesis, with the charge density on the surface of the CNFs and the dosage of the surfactant polyvinylpyrrolidone (PVP) being carefully adjusted. The obtained CNF@MOF nanofibers with long-range, continuous, hybrid nanostructures were very different to the composites formed by aggregation of MOF nanoparticles on the substrates. Four typical MOFs (HKUST-1, Al-MIL-53, Zn-MOF-74, ZIF-CO -1) were successfully grown onto CNFs in aqueous solutions and further fabricated into freestanding nanopapers. Because of their unique nanostructures and morphologies, the corresponding flexible nanopapers exhibit hierarchical meso-micropores, high optical transparency, high thermal stability, and high mechanical strength. A proof-of-concept study shows that the CNF@MOF nanopapers can be used as efficient filters to separate volatile organic compounds (VOCs) from the air. This work provides a new path for structuring MOF materials that may boost their practical application.
通过将金属-有机骨架 (MOF) 组装到纤维素纳米纤维 (CNF) 上，制备了独立式纳米纸。通过界面合成，CNF 被连续成核的 MOF 层 (CNF@MOF) 包裹，仔细调整 CNF 表面的电荷密度和表面活性剂聚乙烯吡咯烷酮 (PVP) 的用量。所得的 CNF@MOF 纳米纤维具有长程、连续、混合的纳米结构，与在基底上聚集的 MOF 纳米颗粒形成的复合材料有很大的不同。四种典型的 MOF（HKUST-1、Al-MIL-53、Zn-MOF-74、ZIF-CO -1）在水溶液中成功地生长在 CNF 上，并进一步制备成独立式纳米纸。由于其独特的纳米结构和形态，相应的柔性纳米纸表现出分级介孔-微孔、高光学透明度、高热稳定性和高机械强度。概念验证研究表明，CNF@MOF 纳米纸可用作高效过滤器，从空气中分离挥发性有机化合物 (VOC)。这项工作为 MOF 材料的结构提供了一条新途径，可能会推动其实际应用。
