PA/蒽醌/PVDF复合纳滤膜结构与性能及其应用

Structure, properties and application of PA/Anthraquinone/PVDF composite nanofiltration membrane

以聚偏二氟乙烯(PVDF)超滤膜为基膜,采用聚乙烯亚胺(PEI)与单宁酸(TA)和没食子酸(GA)的混合物共沉积后,再与均苯三甲酰氯(TMC)进行界面聚合的方法制备了PVDF复合纳滤膜,探讨了TA与GA的混合质量比例对PVDF复合纳滤膜选择层的微观结构和性能的影响,分别采用FTIR、AFM、SEM和水接触角测量仪对复合纳滤膜选择层的化学结构、表面粗糙度、微观结构和表面亲水性进行了表征,考察了PVDF复合纳滤膜在模拟RB5-NaCl染料废水处理中的性能和稳定性。结果表明:随着TA:GA比例的增加,选择层的表面粗糙度增加、水接触角减小,纯水通量增加,PEG1000截留率略有降低;染料废水通量和截留率呈相同的变化趋势,染料和盐的分离因子达到12.97;PVDF复合纳滤膜在运行时间内表现出良好的稳定性。

PVDF composite nanofiltration membrane was prepared by a co-precipitation between the base membrane of polyvinylidene fluoride(PVDF) ultrafiltration membrane and a mixture of PEI and tannic acid(TA) and gallic acid(GA) at first, then the interfacial polymerization with homophthalic chloride(TMC). The effects of the mixing ratio of TA and GA on the microstructure and properties of the selective layer of PVDF composite nanofiltration membranes were investigated. FTIR, AFM, SEM, and water contact angle measurement instruments were used to characterize the chemical structure, surface roughness, microstructure and surface hydrophilicity of the composite nanofiltration membrane selective layer. The performance and stability of the PVDF composite nanofiltration membrane on simulated RB5-NaCl dye wastewater treatment were investigated. The results showed that with the increase of TA:GA ratio, the surface roughness of the selective layer increased, the water contact angle decreased, the pure water flux increased, and the retention rate of PEG1000 decreased slightly;the flux and retention rate of dye wastewater showed the same trend, and the separation factor of dye and salt reached 12.97. PVDF composite nanofiltration membrane showed a good stability during the operation.