基于GO构筑限域空间制备超薄ZIF-67膜及其丙烯/丙烷分离性能研究

膜分离技术用于丙烯/丙烷分离具有能耗低、效率高的特点，有望取代高耗能的低温精馏过程。高分离选择性、高通量和高稳定分离膜的制备是实现该技术工业应用的关键。基于沸石咪唑酯骨架材料（ZIF-67）能够有效分离丙烯/丙烷的特点，项目拟以二维多孔氧化石墨烯GO构筑限域空间，采用同源金属自转化法制备超薄ZIF-67膜，通过优化合成条件并利用GO限域作用，调控ZIF-67晶粒尺寸和定向生长，减少晶间界非分子筛孔道缺陷，降低膜厚，实现膜材料分离选择性和渗透通量的提升；并通过系统研究不同成膜过程制备的ZIF-67膜的微结构和丙烯/丙烷分离性能，探索ZIF-67膜在GO限域作用下的成膜机理，揭示膜的构筑基元形貌及膜厚与丙烯/丙烷分离性能和膜稳定性的关联性，为高性能丙烯/丙烷分离膜的设计和制备提供新的研究思路和理论依据。

Membrane-based separation processes used for separation of propylene/propane mixtures has been considered as one of potential alternative to the energy-intensive cryogenic distillation duo to its low energy consumption and high efficiency. High selectivity, high permeance and high stability of the membrane preparation is the key to realize the industry application of this technology. In this proposal, in view of the recent demonstration of promising separation of propylene/propane by zeolitic imidazolate frameworks-67 (ZIF-67), two-dimensional porous graphene oxide （GO）is used to construct the confined spaces to prepare ultrathin ZIF-67 membrane by homogeneous metal self-conversion method. The microstructure of the ZIF-67 membrane is controlled by optimizing the synthesis condition and combining with the confined space effect of GO，including controlling the size and orientation of the crystal growth, and reducing the non-selective intercrystalline diffusion of molecules through the grain boundary and membrane thickness，then the permeance and selectivity of the membrane can be improved through the microstructural optimization. The separation performances of propylene/propane and microstructures of the ZIF-67 membranes prepared by different synthetic methods are studied systematically, followed by exploration the possible growth mechanism of ZIF-67 membranes with the confined space effect of GO, and the effects of the morphology of the building blocks of membrane and membrane thickness on separation performance and long-term stability for propylene/propane are also be clarified. This project will provide a novel strategy and theoretical support for design and preparation high-performance membrane for separation propylene/propane mixtures.