Archana Yadav K M, Mishra Girish, Kundu Susmita, Ghosh Soumya, Haldar Ritesh
Tata Institute of Fundamental Research Hyderabad Gopanpally 500046 Hyderabad India
Chem Sci. 2025 Sep 3. doi: 10.1039/d5sc04618a.
Zeolitic imidazolate framework-8 (ZIF-8), constructed from Zn ions and 2-methylimidazole (mIm) linkers, is widely recognized for its excellent thermal and chemical stability, making it a strong candidate for chemical separation and heterogeneous catalysis. In this study, we report a new crystalline phase of functionalized ZIF-8 featuring a spatially graded distribution of chemical functionalities. This anisotropic functionalization is achieved a vapor-phase process applied to a ZIF-8 monolithic film. Anisotropic diffusion of a reactive linker-imidazole-2-carboxaldehyde (CHO-Im)-into the ZIF-8 monolith results in a gradient incorporation of CHO-Im, yielding a ZIF-8-CHO monolith. Spatial anisotropy of the CHO functional groups is confirmed through X-ray diffraction, scanning electron microscopy, and vibrational spectroscopy. To demonstrate its potential, we fabricated an anodic aluminium oxide-supported membrane and highlighted its enhanced gas permselectivity compared to pristine membranes.
由锌离子和2-甲基咪唑（mIm）连接体制成的沸石咪唑酯骨架-8（ZIF-8），因其出色的热稳定性和化学稳定性而广受认可，这使其成为化学分离和多相催化的有力候选材料。在本研究中，我们报告了一种功能化ZIF-8的新晶相，其具有化学官能团的空间梯度分布。这种各向异性功能化是通过将气相过程应用于ZIF-8整体膜来实现的。反应性连接体-咪唑-2-甲醛（CHO-Im）向ZIF-8整体的各向异性扩散导致CHO-Im的梯度掺入，从而产生ZIF-8-CHO整体。通过X射线衍射、扫描电子显微镜和振动光谱证实了CHO官能团的空间各向异性。为了证明其潜力，我们制备了一种阳极氧化铝支撑膜，并强调了其与原始膜相比增强的气体渗透选择性。
