智能膜开关尺寸与孔径的匹配性对膜响应性能的影响规律

摘要

智能膜的响应性能是其主要性能之一.本文借助计算流体力学(CFD)模拟,以孔壁排布有聚 N-异丙基丙烯酰胺(PNIPAM)智能微球的单直膜孔为模型,定量系统地考察了智能微球的响应倍数以及微球尺寸与膜孔径的匹配性对膜温度响应性能的影响规律,并通过实验验证了模拟结果的可靠性.CFD 模拟结果表明,当智能开关与膜孔径的相对比值一定时,温度响应开关系数随着微球响应倍数的减小而逐渐增大.当相对比值小于0.4时,实测的温度响应开关系数与固载量100%的模拟结果相吻合;而当相对比值大于0.4时,其与固载量为67%的模拟结果相吻合.通常当相对比值在0.4~0.65之间时,智能膜可以同时获得良好的温度响应性能和稳定的渗透性能.该研究结果可望为设计和制备高性能智能膜提供理论指导和实验基础.%The responsibility is one of the key properties of the smart membranes. In this paper,the effect of both the thermo-responsive factor of smart microgels and the size ratio of smart microgels to membrane pores on the responsibility of the smart membranes was quantitatively and systematically investigated using computational fluid dynamics(CFD)based on the straight single-pore model with poly(N-isopropylacrylamide) (PNIPAM) smart microgels immobilized on the wall of the pores. To investigate the accuracy of the CFD simulation results,the thermo-responsive gating coefficients of smart membranes were also experimentally measured. The CFD simulation results showed that when the size ratio of smart microgels to membrane pores was constant,the thermo-responsive gating coefficient of smart membranes increased with the decrease of the thermo-responsive factor of smart microgels. When size ratio was less than 0.4,the measured thermo-responsive gating coefficient was in accordance with the simulation results of the PNIPAM content of 100%. However,the measured results agreed with the simulation results of the PNIPAM content of 67% when the size ratio was larger than 0.4. In general,the satisfactory responsibility and stable permeability of smart membranes were achieved simultaneously when the size ratio was in the range of 0.4 to 0.65. The results will provide valuable guidelines and experimental foundation for the design and fabrication of smart membranes with high performances.