超亲水天然多酚改性膜的制备及其油水分离性能

Preparationof superhydrophilic natural polyphenol modified membraneand its oil-water separation performance

摘要:

为研发绿色环保、制备工艺简单的油水分离材料，以单宁酸（TA）和聚乙二醇（PEG）为改性剂，聚偏氟乙烯（PVDF）膜为基底，通过简单浸渍法，制备了超亲水复合膜（TAPE膜）。采用SEM、AFM、FTIR、XPS和接触角测定仪对TAPE膜进行了表征和分析，并研究了TAPE膜的油水分离性能、耐磨性能和稳定性能。结果表明，TAPE膜具有多孔微纳米粗糙结构，当TA含量为蒸馏水质量的1.75%时，该膜的水接触角和水下油接触角分别为0°和156°，表现出超亲水性和水下超疏油性。在0.09 MPa压力下，TAPE膜分离乳化油的膜通量为1146.4 L/(m2·h)，是原始PVDF膜的12倍，该膜对油水混合液和乳化油的分离效率可达99.9%。此外，TAPE膜具有良好的稳定性，膜表面经砂纸（320目）磨损（100 g载重）25次后水接触角仍高达152°，该膜在油水分离领域具有潜在的应用前景。

Abstract:

In order to prepare simple and environmentally friendly oil-water separation materials, superhydrophilic composite membrane (TAPE) was prepared by simple impregnation method with natural polyphenol tannic acid (TA) and polyethylene glycol (PEG) as raw materials and polyvinylidene fluoride (PVDF) membrane as substrate. The TAPE film was characterized by SEM, AFM, FTIR, XPS and contact angle instrument. The oil-water separation performance, wear resistance and stability of TAPE film were studied. The results show that the TAPE membrane has a porous micro-nano rough structure. When the TA content is 1.75 % of the mass of distilled water, the water contact angle and underwater oil contact angle of the membrane about 0° and 156°, respectively, showing superhydrophilicity and underwater superoleophobicity. Under the pressure of 0.09 MPa, the membrane flux of TAPE membrane for separating emulsified oil was 1146.4 L/(m2·h), which was 12 times that of the original PVDF membrane. The separation efficiency of oil-water mixture and emulsified oil could reach 99.9 %. In addition, the TAPE membrane has good stability, and the water contact angle of the membrane surface is still as high as 152° after 25 times of sandpaper detrition (320 mesh) under 100 g of loading. The membrane has potential application prospects in the field of oil-water separation.