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

摘要:

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，制备具有稳固微纳米涂层的超亲水/水下超疏油TA-PVA-CuⅡ@PVDF滤膜。结果表明，在亲水性TA-PVA-CuⅡ微纳米涂层的作用下，TA-PVA-CuⅡ@PVDF膜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分别可达1169.30 L /(m2·h)和99.99%，展现出优异的油水分离性能。此外，对比分析二价铜离子改性时间对TA-PVA-CuⅡ@PVDF膜循环使用性以及涂层耐久性的影响，发现二价铜离子改性时间为20 min时，TA-PVA-CuⅡ@PVDF膜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%。

Abstract:

In order to solve the issue of poor recyclability of oil/water separated filter membrane, tannic acid-copper (TA-CuⅡ) was adhered by supramolecular binder of tannic acid-polyvinyl alcohol (TA-PVA) to form tannic acid-polyvinyl alcohol-copper (TA-PVA-CuⅡ) coating modified polyvinylidene fluoride (PVDF) filter membrane, and the superhydrophilic/underwater superoleophobic TA-PVA-CuⅡ@PVDF membrane with stable micro-nano coating was prepared. The results showed that under the function of hydrophilic micro-nano coating of TA-PVA-CuⅡ, the water contact angle and underwater oil contact angle of TA-PVA-CuⅡ@PVDF membrane respectively was 0° and 151.0°. In addition, the membrane flux and separation efficiency of TA-PVA-CuⅡ@PVDF membrane about emulsified oil could reach 1169.30 L/(m2·h) and 99.99%, respectively, which exhibited excellent oil/water separation performance. Moreover, the effect of CuⅡ modification time on the recyclability and coating durability of TA-PVA-CuⅡ@PVDF membrane was compared and analyzed. It was found that the TA-PVA-CuⅡ@PVDF membrane modified by CuⅡ for 20 min had the best recyclability and coating durability with 15 cycles of separation times and the flux change rate of which was 6.6%.