过硫酸铵改性聚乙烯醇膜的制备及渗透汽化性能

Preparation and Pervaporation Characteristics of Poly (Vinyl Alcohol) Membrane Modified by Ammonium Persulfate

以过硫酸铵(APS)为交联引发剂,引发聚乙烯醇(PVA)自交联,并复合在聚丙烯腈(PAN)超滤支撑膜表面,制备了PVA/PAN渗透汽化复合膜。采用扫描电镜和X射线衍射仪表征了交联膜的形貌和物理结构变化,由电镜观察到,在PAN超滤膜上形成了一层致密分离层,厚度为10μm。研究了膜在乙醇水溶液中的溶胀行为,测定了膜的凝胶分数,结果表明,APS含量增加,膜的结晶度下降,凝胶分数增加,溶胀度减小。通过考察膜对95%乙醇水溶液的渗透汽化分离性能可知,随着APS含量增加,膜的渗透通量先上升后下降,膜透过侧含水量始终保持在99%以上。

Poly（vinyl alcohol） （PVA）/polyacrylonitrile （PAN） composite membrane was prepared by cross-linking reaction of PVA and ammonium persulfate （APS）. The cross-linked membranes were characterized by scanning electron microscopy and wide-angle X-ray diffraction. SEM images show that a dense layer with the thickness of 10μm is upon the PAN ultrafiltration membrane. The swelling degree of PVA and cross-linked PVA membranes in ethanol aqueous solution was studied; the gel fraction of the cross-linked PVA membranes was measured. The pervaporation performance was investigated by separation of 95% ethanol aqueous solution. The results show that the swelling degree and crystalline region of PVA membranes decrease with increasing of APS content, meanwhile, the gel fraction of the PVA membranes increases. The APS content also affects the separation performance. As the content of APS increasing, the flux first increases and then decreases, the permeate mass fraction of water always keeps more than 99%.