基于强氢键作用的超分子微纳米涂层改性滤膜

Supramolecular micro-nano coating based on strong hydrogen bonding modified filter membrane

为解决油水分离滤膜循环使用性差的问题,采用超分子鞣酸-聚乙烯醇(TA-PVA)黏结剂黏附鞣酸-铜(TA-CuⅡ)形成鞣酸-聚乙烯醇-铜(TA-PVA-CuⅡ)涂层改性聚偏氟乙烯(PVDF)膜,制备了具有稳定微纳米涂层的超亲水/水下超疏油膜(TA-PVA-CuⅡ@PVDF)。采用SEM、FTIR、XPS对制备的膜进行了表征,对改性前后PVDF膜的表面润湿性、油水分离性进行了测试,考察了二价铜离子改性时间对TA-PVA-CuⅡ@PVDF循环使用性以及涂层耐久性的影响。结果表明,在亲水性TA-PVA-CuⅡ微纳米涂层的作用下,TA-PVA-CuⅡ@PVDF的水接触角和水下油接触角分别可达到0°和151.0°,其对乳化油的分离膜通量和分离效率最高分别可达1169.30 L/(m^(2)·h)和99.99%,展现出优异的油水分离性能。二价铜离子改性时间为20 min时,TA-PVA-CuⅡ@PVDF循环稳定性和耐久性最佳,具有15次的循环分离次数,并且通量改变率为6.6%。

In order to solve the problem of poor recyclability of oil/water separation filter membrane,superhydrophilic/underwater superoleophobic tannic acid-polyvinyl alcohol-copper(TA-PVA-CuⅡ)coating modified polyvinylidene fluoride(PVDF)filter membrane(TA-PVA-CuⅡ@PVDF)was synthesized from modification of PVDF membrane with stable micro-nano coating obtained as adhesive of tannic acid-copper(TA-CuⅡ)with supramolecular tannic acid-polyvinyl alcohol(TA-PVA)as adhesive,and characterized by SEM,FTIR and XPS.The surface wettability and oil-water separation performance of PVDF membrane before and after modification were evaluated,while the influence of bivalent copper ion modification time on the reusability of TA-PVA-CuⅡ@PVDF and the durability of the coating were further investigated.The results showed that under the function of hydrophilic micro-nano coating of TA-PVA-CuⅡ,the TA-PVA-CuⅡ@PVDF exhibited a water contact angle of 0°and underwater oil contact angle of 151.0°.In addition,the membrane flux and separation efficiency of TA-PVA-CuⅡ@PVDF about emulsified oil could reach 1169.30 L/(m^(2)·h)and 99.99%,respectively,indicating excellent oil/water separation performance.The TA-PVA-CuⅡ@PVDF modified by CuⅡfor 20 min showed the best recyclability and coating durability with 15 cycles of separation times and a flux change rate of 6.6%.