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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SrCo_(0.4)Fe_(0.4)Zr_(0.2)O_(3-δ)(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、SrZrO_3相及Co_3O_4相组成,SrZrO_3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~(-7)mol/(cm~2·s),并且在160 h的测试周期内保持稳定.
Based on the theory of phase separation, the hollow fiber membranes of SrCo_ (0.4) Fe_ (0.4) Zr_ (0.2) O_ (3-δ) SCFZ mixed conductors were prepared by wet-dry spinning technique and subsequent sintering process. , SEM, thermal expansion analysis and oxygen permeability analysis were used to study the crystal structure, the morphology of the membrane, the sintering behavior of the green hollow fiber membrane and the membrane oxygen permeation flux.The results showed that the hollow The crystal structure of fiber membrane consists of the main phase of perovskite, SrZrO_3 phase and Co_3O_4 phase, and the content of SrZrO_3 phase increases with the increase of sintering temperature. There are finger-like pores in the inner and outer cortex of the membrane section, sponge pores in the middle of the membrane wall, The structure was formed by immersion phase separation of the polymer solution.A comprehensive sintering behavior, XRD and SEM results, combined with air tightness and mechanical strength test, to determine the appropriate sintering temperature of the green body 1240 ° C. SCFZ hollow fiber prepared under these conditions The membrane has excellent mechanical properties and breaking strength of 74.19MPa at three bending moment. The oxygen permeation flux under air / helium gradient is 2.9 × 10 -7 mol / (cm ~ 2 · s) at 850 ℃, and Stable over the 160 h test period.