取向调控制备超薄MOF膜用于气体分离  

Preparation of Ultrathin MOF Membranes for Gas Separation by Orientation Regulation

作　　者：陈慧 刘玉涛 李晋平[1] 李立博[1] CHEN Hui;LIU Yutao;LI Jinping;LI Libo(College of Chemical Engineering and Technology,Taiyuan University of Technology,Taiyuan 030024,China)

机构地区：[1]太原理工大学化学工程与技术学院,太原030024

出　　处：《太原理工大学学报》2023年第6期978-987,共10页Journal of Taiyuan University of Technology

基　　金：国家自然科学基金资助项目(22278287,22090062);国家重点研发计划资助项目(2022YFB3806802);山西省基础研究计划(202203021222119)。

摘　　要：【目的】超薄无缺陷MOF膜的制备存在着巨大挑战。控制MOF膜的生长取向,有利于减少晶间缺陷并优化成膜厚度。【方法】首次采取聚多巴胺(PDA)中间层介导策略,在多孔基底上制备了具有一定取向的超薄UTSA-280 MOF膜。PDA层通过与金属离子的多重相互作用为UTSA-280提供了丰富的吸附、锚定位点,促进UTSA-280异相成核和生长。进一步通过改变PDA层的沉积量,可以调控成核密度和生长速率,从而调控MOF晶体的生长取向和厚度。【结果】最优化条件下制备的晶面(202)取向生长的UTSA-280 MOF膜厚为162 nm,其H_(2)渗透速率可达4141.8 GPU,H_(2)/CO_(2)分离选择性最高达18.5,远超2008年Robeson上限。【Purposes】Metal-organic framework(MOF)membranes have been extensively studied in recent years owing to their rich porosity as well as their uniform and adjustable pore size.Still,the preparation of ultra-thin and defect-free MOF membranes faces great challenges.Controlling the growth orientation of the MOF membranes helps reduce intergranular defects and optimize membrane thickness.【Methods】For the first time,an ultra-thin and oriented UTSA-280 MOF membrane is prepared on a porous substrate via a polydopamine(PDA)interface layermediation strategy.The PDA layer provides abundant adsorption and anchoring sites for UTSA-280 through multiple interactions with metal ions to facilitate the heterogeneous nucleation and growth of UTSA-280.Furthermore,the nucleation density and growth rate can be controlled through varying PDA deposition amounts to modulate the growth orientation of MOF crystals and membrane thickness.【Findings】Finally,a(202)-oriented UTSA-280 MOF membrane prepared under optimal conditions with a membrane thickness of 162 nm achieves H_(2)permeance up to 4141.8 GPU and H_(2)/CO_(2)separation selectivity of 18.5,far exceeding the Robeson upper bound in 2008.

关 键 词：金属-有机框架膜 气体分离 UTSA-280 取向生长 聚多巴胺 

分 类 号：TB383[一般工业技术—材料科学与工程]