Abstract:

Zeolite membranes have been used in pervaporation, membrane distillation, gas separation, etc. due to their high efficiency, energy-saving and stability. However, the intercrystalline defects of zeolite layer seriously reduce the separation performance, which hinders the further application of zeolite membranes. In this paper, the latest researches on the defects control and repair were reviewed and classified as “control during synthesis” or “remediation after synthesis”. In “control during synthesis” section, the factors that caused intercrystalline defects in the process of zeolite layer formation were summarized, including supports properties, zeolite seed properties, seeding method, secondary growth parameters and template-removal method. In “remediation after synthesis” section, necessary modification/blocking technologies were introduced since intercrystalline defects still existed after improved preparation. The general idea about defect elimination was to improve the intergrowth of zeolite crystals, reduce thermally induced cracking and develop more accurate, efficient and energy-saving remediation technology. In the future, to meet higher industrialization requirements, it will be necessary to integrate the defect control and remediation technologies during the whole preparation process, and develop membrane technologies with low cost, low energy consumption and short process.

Key words: molecular sieves, zeolite, membranes, intercrystalline defects, control, remediation

摘要：

分子筛膜因其高效、节能、稳定的特点，已应用于渗透汽化、膜蒸馏、气体分离等领域。然而，膜面晶间缺陷是影响分子筛膜分离性能的主要因素之一，阻碍分子筛膜进一步工业应用。本文从“合成中控制技术”和“合成后修复技术”两个角度综述了近年来国内外研究者对分子筛膜晶间缺陷控制与修复技术的最新研究进展。其中，“合成中控制”部分主要关注分子筛膜层生长过程中导致缺陷生成的因素及其控制手段，包括支撑体性质、分子筛晶种性质、晶种涂覆方式、二次水热生长调节方式和焙烧脱模方式等；“合成后修复”部分主要介绍了应对成膜后晶间缺陷的修饰与封堵技术。消除晶间缺陷的总体思路是通过技术手段增强晶体面内交互共生特性、减少热致开裂以及开发更加精准、高效、低耗的修复技术。未来，面对更高的产业化要求，应整合制备全流程的缺陷控制与修复手段，开发低成本、低能耗、短流程的膜制备技术。

关键词: 分子筛, 沸石, 膜, 晶间缺陷, 控制, 修复