担载膜受限烧结孔结构模型的改进及验证  

Improved pore evolution model for supported membrane during constrained sintering process

作　　者：邱鸣慧[1] 冯君[1] 范益群[1] 徐南平[1] 

机构地区：[1]南京工业大学化学化工学院,材料化学工程国家重点实验室,江苏南京210009

出　　处：《化工学报》2010年第3期767-772,共6页CIESC Journal

基　　金：国家重点基础研究发展计划项目(2009CB623400);国家高技术研究发展计划项目(2007AA030303);国家自然科学基金项目(20776067)~~

摘　　要：针对担载膜受限条件下,复杂的堆积方式及垂直膜面方向出现的加速收缩将影响孔径的问题,对前期建立的担载膜孔结构预测模型进行了改进,从两个方面对模型的关键参数进行定量修正。考虑制备过程中颗粒可能形成的软团聚体对初始堆积方式的影响,对模型重要参数——初始孔隙率进行调整;并结合受限烧结应力模型计算担载膜在垂直膜面方向上的收缩速率和收缩率,研究该方向加速收缩对孔径的影响。在此基础上,采用改进的模型对ZrO2担载膜在800～1200℃烧结后,孔径、孔隙率、膜厚等微结构进行了预测。结果表明:与原模型相比,改进模型具有更好的适应性以及更高的计算精度,能更准确地预测不同烧结温度制备的担载膜的孔径和膜厚,为陶瓷膜孔径的预测与定量控制提供了有效的工具。进一步将模型计算值代入Hagen-Poiseuille方程,可以预测膜的纯水渗透通量。To solve the problem of stacking complexity and different shrinkage perpendicular to the membrane during constrained sintering process,an improved pore evolution model with key parameters was improved.Considering the aggregation,initial porosity as the critical parameter of model was adjusted.Then the shrinkage and shrinkage rate in the perpendicular direction to the membrane could be calculated with the theory of constrained sintering,and its effect on the pore size of supported membrane was investigated.On the basis of the improved model,the change of mean pore size,porosity and thickness of zirconium supported membrane with sintering temperature could be predicted quantitatively in the temperature range from 800℃ to 1200℃.The prediction calculated from the improved model fitted the experimental data better than that from the previous model.It provides an effective tool in predicting and controlling the pore size of ceramic membranes during the sintering process.Furthermore,substituting the pore size,porosity and membrane thickness calculated from the model into Hagen-Poiseuille law predicted the pure water flux accurately.

关 键 词：受限烧结 孔结构 模型改进 ZrO2担载膜 

分 类 号：TQ050.4[化学工程]