天津大学姜忠义团队开发了一种离子共价有机框架纳米片的油、水、油三相合成方法。相关研究成果发表在2021年10月7日出版的《德国应用化学》。

离子共价有机框架纳米片（iCOFNs）具有长程有序和单分散的离子基团，在许多先进应用中具有巨大潜力。

考虑到油水两相法的固有缺陷，该文探索了一种基于相工程策略的自下而上合成iCOFNs的油水三相法。中间水相作为一个封闭的反应区，两个油相是储存和向水相供应单体的储层。较大的水空间和较低的单体浓度导致iCOFNs的各向异性逐渐生长为较小的层厚、较大的横向尺寸和较高的结晶度。值得注意的是，由此产生的三种阳离子和阴离子iCOFNs表现出高达20000的超高纵横比。研究人员通过将其加工成超薄无缺陷的COF膜以实现高效的沼气分离，进一步证明了其应用潜力。

该三相方法可能为iCOFNs的合成和创新应用提供一种替代平台技术。

附：英文原文

Title: Oil?water?oil triphase synthesis of ionic covalent organic framework nanosheets

Author: Zheyuan Guo, Haifei Jiang, Hong Wu, Leilang Zhang, Shuqing Song, Yu Chen, Chenyang Zheng, Yanxiong Ren, Rui Zhao, Yonghong Li, Yan Yin, Michael D. Guiver, Zhongyi Jiang

Issue&Volume: 2021-10-07

Abstract: Ionic covalent organic framework nanosheets (iCOFNs) with long-range ordered and mono-dispersed ionic groups hold great potential in many advanced applications. Considering the inherent drawbacks of oil-water biphase method, herein, we explore an oilwateroil triphase method based on phase engineering strategy for the bottom-up synthesis of iCOFNs. The middle water phase serves as a confined reaction region, and the two oil phases are reservoirs for storing and supplying monomers to the water phase. A large aqueous space and low monomer concentration lead to the anisotropic gradual growth of iCOFNs into few-layer thickness, large lateral size, and high crystallinity. Notably, the resulting three cationic and anionic iCOFNs exhibit ultra-high aspect ratios of up to 20,000. We further demonstrate their application potential by processing into ultrathin defect-free COF membranes for efficient biogas separation. Our triphase method may offer an alternative platform technology for the synthesis and innovative applications of iCOFNs.

DOI: 10.1002/anie.202112271

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202112271