中空硅氧碳陶瓷纤维膜的制备及气体分离性能研究

项目名称： 中空硅氧碳陶瓷纤维膜的制备及气体分离性能研究

项目编号： No.51502045

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 一般工业技术

项目作者： 闫啸

作者单位： 广州中国科学院先进技术研究所

项目金额： 21万元

中文摘要： 中空陶瓷纤维膜由大孔径支撑体和小孔径过滤层组成，具有结构简单，分离效果好，有效膜面积大等优点，有望实现高温气体的高效分离。但传统的中空陶瓷纤维膜的过滤层材料，如沸石，多孔炭，二氧化硅等，存在水热稳定性差，成型温度高等不足，限制了其在高温气体分离领域的应用。硅氧碳前驱体陶瓷具有高化学惰性和水热稳定性，高机械强度，耐高温等优势，同时可在较低温度陶瓷化，是一种具有应用前景的新型膜材料。针对硅氧碳在热解时易开裂形成缺陷的不足，本研究提出一个制备无缺陷中空陶瓷纤维膜的方案，通过在聚硅氧烷前驱体中添加第二相抑制热解时前驱体的收缩，采用溶胶凝胶法在大孔径支撑体上涂覆聚硅氧烷过滤层制备中空硅氧碳纤维膜。本研究探索中空硅氧碳纤维膜的制备过程，研究第二相和缓冲层对材料微结构，成孔机理，支撑体和过滤层的界面结合强度和气体分离性能的关系和影响，为前驱体基中空陶瓷纤维膜的产业化应用提供理论和技术基础。

中文关键词： 溶胶-凝胶；前驱体陶瓷；硅氧碳；气体分离

英文摘要： Ceramic hollow fiber membranes consisting of support layer of micro-sized pores and filter layer of nano-sized pores have many advantages including structure simplicity, excellent separation efficiencies and large effective membrane areas and can effectively realise gas seperation. However, traditional filter materials, such as zeolites, carbon, and silica, have shortcomings like poor hydrothermal stability and high sintering temperature, inhibiting their practical application in terms of gas separation. Polymer derived ceramics like silicon oxycarbides(SiOC) offer an attractive combination of chemical and physical properties including chemical inertia, high hydrothermal stability, high mechanical strength, high temperature resistance and low ceramic conversion temperature, and therefore are considered as potential alternatives. Hereby, we propose a novel method for fabricating defect-free SiOC based hollow fiber membranes to inhibit the cracking tendency of SiOC ceramics during pyrolysis. In this study, polysiloxanes are mixed with suitable additives before being coated onto zirconia supports and then converted to SiOC based hollow fiber membranes through high temperature pyrolysis. Fabrication process, heat treatment and pyrolysis behavior will be investigated. Effect of the additives and the buffer layer on the interface strength between supports and filter layer as well as on the membrane structure and gas separation properties will be studied, to provide theoretical understanding and technology support for the industrial application of polymer derived ceramics based ceramic hollow fiber membranes.

英文关键词： Sol-gel;polymer derived ceramics;silicon oxycarbide;gas separation