SrCo0.4Fe0.4Zr0.2O3-d混合导体中空纤维膜的制备及其氧渗透性能
收稿日期: 2009-12-10
修回日期: 2010-03-05
网络出版日期: 2010-07-19
基金资助
国家973计划项目(2009CB623406); 国家自然科学基金(20990222); 江苏省六大人才高峰项目(2007007)
Preparation and Oxygen Permeation of SrCo0.4Fe0.4Zr0.2O3-d Mixed-conducting Hollow Fibre Membrane
Received date: 2009-12-10
Revised date: 2010-03-05
Online published: 2010-07-19
基于相分离理论, 采用干湿法纺丝技术结合后续的烧结工艺, 制备出SrCo0.4Fe0.4Zr0.2O3-d(SCFZ)混合导体中空纤维膜. 借助于XRD、SEM、热膨胀分析以及氧渗透性能分析等手段, 分别对样品的晶相结构, 膜的微观形貌,中空纤维膜生坯的烧结行为以及膜的氧渗透通量进行了研究. 结果表明, 中空纤维膜晶相结构由钙钛矿主体相、 SrZrO3相及Co3O4相组成, SrZrO3相含量随烧结温度升高而增大. 膜断面邻近内外皮层均存在指状孔, 膜壁中部区域为海绵孔, 此结构由聚合物溶液沉浸相分离形成. 综合烧结行为, XRD及SEM结果, 再结合气密性和机械强度测试, 确定生坯适宜的烧结温度为1240℃. 在此条件下制备的SCFZ中空纤维膜力学性能优异, 三弯矩断裂强度达到74.19MPa, 在850℃时, 空气/氦气梯度下的氧渗透通量为2.9´10-7mol/(cm2·s), 并且在160 h的测试周期内保持稳定.
戚 律, 董学良, 刘郑堃, 张广儒, 金万勤 . SrCo0.4Fe0.4Zr0.2O3-d混合导体中空纤维膜的制备及其氧渗透性能[J]. 无机材料学报, 2010 , 25(8) : 871 -876 . DOI: 10.3724/SP.J.1077.2010.00871
SrCo0.4Fe0.4Zr0.2O3-d (SCFZ) mixed conducting hollow fibre membranes were prepared by a dry-wet spinning technology based on the phase separation theory combined with subsequent sintering process. XRD, SEM, thermal expansion technique and oxygen permeation test were utilized to characterize the crystal phase structures, microstructures, sintering behavior and oxygen permeation flux of SCFZ powder and/or hollow fibre membranes. XRD patterns show that the crystal phase of SCFZ hollow fibre membranes are composed of perovskite main phase, SrZrO3 and Co3O4 impurity phases. The content of SrZrO3 increases with increasing the sintering temperature. The SEM images demonstrate that fingerlike pores exist adjacent to the inner and outer skin layer of membrane wall. Meantime, sponge-like pores appear in the middle zone of wall. This kind of morphology is caused by the immersion phase separation process. From the gastight, mechanical strength, sintering behavior, XRD and SEM results, the optimum sintering temperature of the green membranes is considered to be 1240℃. The SCFZ hollow fibre membranes are obtained under the optimum sintering schedule. The sintered SCFZ membranes exhibit high mechanical strength and the fracture strength reaches 74.19MPa. At 850℃, the oxygen permeation flux of the membrane is 2.9´10-7mol/(cm2 · s) under air/He gradient, and the flux is stable during the test for more than 160h.
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