疏水膜材料的膜孔润湿与干燥研究

Research of wetting and drying of the hydrophobic membrane pore

针对疏水膜润湿后的膜孔干燥问题,提出一种新的膜孔干燥方法,认为疏水膜存在一个临界润湿深度和自脱水效应,当膜孔被润湿深度小于该疏水膜材料的临界润湿深度时,利用表面张力的作用,疏水膜可以实现膜孔的自脱水。以十二烷基苯磺酸钠溶液作为快速污染物,用聚偏氟乙烯中空纤维疏水膜进行减压膜蒸馏的润湿与自脱水干燥实验,实验结果表明,对于所使用的3种不同厚度的膜丝,疏水膜的确存在临界润湿深度,其值均为(19.5±0.5)μm,与所用膜丝的厚度无关。在膜孔润湿深度小于临界润湿深度时对疏水膜进行清洗,可以实现疏水膜的自脱水干燥,从而实现膜蒸馏过程的持续运行。

For the problem that the drying of the hydrophobic membrane pore,we proposed a new method of drying the membrane pore that there is a critical wetting depth and automatic dehydration effect for hydrophobic membrane.When the wetting depth of membrane pore is less than the critical wetting depth,the membrane can realize automatic dehydration under the effect of surface tension.In this paper,sodium dodecyl benzene sulfonate solution was used as quickly pollutants,The polyvinylidene fluoride(PVDF)hollow fiber hydrophobic membrane was applied in vacuum membrane distillation(VMD)process for the research of the membrane pore wetting and dehydration drying.The results showed that,for the three membranes with different thickness,there is a critical wetting depth for hydrophobic membrane,its values are(19.5±0.5)μm,the depth was not associated with the thickness of the membrane.Clean the membrane when the wetting depth was less than the critical wetting of the hydrophobic membrane,the hydrophobic membrane's automatic dehydration drying can be achieved,enabling continuous operation of membrane distillation process.