聚乙烯醇/聚丙烯复合膜的制备及透湿性研究

Preparation and Moisture Permeability of Polyvinyl Alcohol/Polypropylene Composite Membrane

将氯化锂(LiCl)添加到聚乙烯醇(PVA)水溶液中制成铸膜液,以微孔聚丙烯(PP)膜作为基膜和覆膜,制备了PVA/PP复合膜,采用透湿性测量平台研究了PVA/PP复合膜的透湿性,分析了气体流量、高湿气体进口相对湿度和两侧通道高度对PVA/PP复合膜水蒸气传质通量和湿交换率的影响。结果表明,PVA/PP复合膜可以选择性透过水蒸气,阻止CO_(2)透过;随着LiCl质量浓度的增加,水蒸气传质通量增加;随着气体流量的增加,水蒸气传质通量增加,湿交换率降低;随着PVA/PP复合膜两侧气体湿度差的增大,水蒸气传质通量增加,湿交换率升高;随着两侧通道高度的增加,水蒸气传质通量减小,湿交换率降低。

We added lithium chloride(LiCl)into polyvinyl alcohol(PVA)aqueous solution to obtain a casting membrane solution,and prepared PVA/PP composite membrane by using microporous polypropylene(PP)membrane as the base membrane and coating membrane.Moreover,we studied the moisture permeability of PVA/PP composite membrane by using the moisture permeability measurement platform.Meanwhile,we analyzed the effects of gas flow rate,relative humidity of high moisture flow at inlet,and channel height of two sides on the mass transfer flux of water vapor and moisture exchange rate.The results show that PVA/PP composite membrane can selectively permeate water vapor and prevent CO_(2) from permeating.The mass transfer flux of water vapor increases with the increase of LiCl mass concentration.With the increase of gas flow rate,the mass transfer flux of water vapor increases,and the moisture exchange rate decreases.The larger the humidity difference between the two sides of PVA/PP composite membrane is,the higher the mass transfer flux of water vapor and moisture exchange rate are.With the increase of channel height of two sides,the mass transfer flux of water vapor and moisture exchange rate decrease.