Zhou Yan, Zhang Guohua, Li Bao, Wu Lixin
State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, P. R. China.
ACS Appl Mater Interfaces. 2020 Jul 8;12(27):30761-30769. doi: 10.1021/acsami.0c05947. Epub 2020 Jun 9.
Supramolecular frameworks driven by intermolecular interactions represent a new type of porous materials differing from those driven by covalent or coordination bonding. The intermolecular interaction-induced flexible assembly structures display unique advantages in material processing, structure stimuli response, and recycling. In this work, a two-dimensional (2D) supramolecular ionic framework (SIF) was constructed through the initial ionic interaction between the host cation and polyoxometalate polyanion and then the host-guest inclusion of the formed host ionic complex with a four-arm porphyrin guest molecule following a [2+4] type reaction. Several prepared framework monolayers bearing an orthometric grid structure constituted a nanosheet-like assembly with flexibility and exhibited processability, which provided feasibility for the further preparation of separation membranes via a simple suction procedure of their dispersed suspensions in mixed solvents. The nanofiltration based on the uniform square pores under a slightly reduced pressure successfully achieved precise separation of several types of nanoparticles and molecular clusters in wide distribution at a cutting off value as small as 2.2 nm. These results also implied the potential of the present strategy for more separations at a molecular level and very fine nanoscale.
由分子间相互作用驱动的超分子框架代表了一种新型的多孔材料，不同于由共价键或配位键驱动的材料。分子间相互作用诱导的柔性组装结构在材料加工、结构刺激响应和回收利用方面展现出独特优势。在这项工作中，通过主体阳离子与多金属氧酸盐聚阴离子之间的初始离子相互作用，然后形成的主体离子络合物与四臂卟啉客体分子按照[2+4]型反应进行主客体包合，构建了一种二维（2D）超分子离子框架（SIF）。几个制备的具有正交网格结构的框架单层构成了具有柔性的纳米片状组装体，并表现出可加工性，这为通过将其分散悬浮液在混合溶剂中进行简单抽吸过程进一步制备分离膜提供了可行性。基于均匀方形孔在略减压下的纳滤成功实现了对几种宽分布的纳米颗粒和分子簇的精确分离，截留值低至2.2 nm。这些结果还暗示了本策略在分子水平和非常精细的纳米尺度上进行更多分离的潜力。
