超亲水天然多酚改性膜的制备及其油水分离性能

Preparation and oil-water separation performance of superhydrophilic natural polyphenol modified membrane

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,并考察了TAPE膜的油水分离性能、耐磨性能和稳定性。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工作压力下,TAPE膜分离水包油乳液的膜通量为1146.4 L/(m^(2)·h),是原始PVDF膜的30倍,该膜对油水混合液和水包油乳液的分离效率均可达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°。

Aiming for developing green and environmental-friendly oil-water separation materials with simple preparation processes,superhydrophilic composite membrane(TAPE membrane)was synthesized using tannic acid(TA)and polyethylene glycol(PEG)as modifier,and polyvinylidene fluoride(PVDF)as substrate membrane via simple impregnation method.The TAPE membrane obtained was then characterized by SEM,AFM,FTIR,XPS and contact angle instrument,followed by analyses on its oil-water separation performance,wear resistance and stability.The results indicated that the TAPE membrane,displaying a porous micro-nano rough structure,had water contact angle and underwater oil contact angle of about 0°and 156°respectively when TA content was 1.75%of the mass of distilled water,which demonstrated the superhydrophilicity and underwater superoleophobicity.Moreover,the TAPE membrane exhibited a flux of 1146.4 L/(m^(2)·h),30 times that of the unmodified PVDF membrane,for separation of emulsion oil-in-water under work pressure of 0.09 MPa with the separation efficiency of oil-water mixture and emulsion oil-in-water reaching 99.9%.In addition,the TAPE membrane showed good stability with the water contact angle still maintained at as high as 152°after 25 times of sandpaper detrition(320 mesh)under 100 g of loading.