二乙醇胺溶液对疏水微孔的浸润研究

Membrane wetting in a static diethanolamine solution

分别将疏水性聚偏氟乙烯(PVDF)中空纤维膜以及PVDF平板膜浸泡到二乙醇胺(DEA)水溶液中,直接观测膜质量随时间的变化,研究膜浸润过程;考察了吸收剂温度、浓度、与膜的接触方式等因素对浸润过程的影响。实验结果表明:膜浸润速度并非一成不变,而是呈现先快后慢的明显差异;提高吸收剂的温度和浓度均会促进微孔膜的润湿;当膜孔与大气连通时,膜增重比在快速上升前还会出现短暂的下降,且由于气相阻力较低而导致浸润速度较快。

The wetting process of polyvinylidene fluoride( PVDF) flat and hollow fiber membranes in static diethanolamine( DEA) solution has been investigated by directly measuring the variation of membrane weight. The increase in membrane weight was obtained for different temperatures,concentrations of DEA solution as well as different contact modes between membrane and liquid,and the ratio increased with time. The experimental results indicated that: the increase slowed down significantly after an initial fast growth; a short-term decline appeared before the fast growth when the wet membrane pores came into contact with air; reducing the temperature and concentration of the DEA solution could help to retard the membrane wetting process. Different contact modes also influenced the membrane wetting rate due to the difference in air resistance.