PVDF中空纤维膜在DEA溶液中的自发浸润动力学研究

Study of spontaneous wetting kinetic of PVDF hollow fiber membrane in DEA solution

基于醇胺溶液在疏水膜上的吸附入侵机理,采用表面张力接触角和黏附张力法并结合吸附方程,测得了二乙醇胺(DEA)分子在PVDF中空纤维疏水膜壁上的吸附量.进而明确了液气相压差在自发浸润过程中起到的重要作用,提出了多层三相接触线的观点,并辅以浸润实验进行验证.通过膜孔中侵入溶液的平均质量法计算出DEA溶液在PVDF中空纤维膜孔道中的平均接触角接近90°.并将膜的渗入方程与MATLAB模拟算法相结合,建立了膜的自发浸润动力学模型,与浸润实验结果具有良好的吻合性.

Based on the adsorption and intrusion mechanism of alcohol amine solution on hydrophobic membrane,the surface tension-contact angle and adhesion tension method were used in combination with the adsorption equation to measure the diethanolamine(DEA)molecules on the hydrophobic membrane wall of polyvinylidene fluoride(PVDF)hollow fiber.The amount of adsorption was found to be extremely slow at the solid-liquid interface.Furthermore,the important role of liquid-vapor pressure difference in the spontaneous wetting process was clarified,and the viewpoint of multi-layer three-phase contact line was put forward,supplemented by wetting experiment for verification.The average contact angle of the DEA solution in the PVDF hollow fiber membrane pores was calculated by the average mass method of the intrusion solution in the membrane pores,and it was found to be very close to 90°.Using the membrane wetting equation and MATLAB simulation algorithm,a spontaneous wetting kinetic model of the membrane is established,which is in good agreement with the wetting experiment results.