聚丙烯织物表面超亲水涂层构筑及其油水分离性能

Preparation of superhydrophilic coating on polypropylene fabric and its application in oil-waterseparation

[目的]为得到具有优秀耐久性和高油水分离效率的超亲水性聚丙烯(PP)分离材料。[方法]通过将天然来源的羧甲基纤维素(CMC)与聚丙烯织物共价结合,制备出一种具有超亲水-水下超疏油性能涂层的改性PP织物。通过扫描电镜(SEM)、红外光谱(IR)、X射线光电子能谱(XPS)等手段对改性后的样品进行分析,利用接触角测量仪和自建油水分离装置测试了改性PP织物的润湿性及油水分离性能。[结果]改性PP织物在空气中的水接触角低至0°,在水下对不同油(包括正己烷、甲苯、煤油、柴油、汽油和石油醚)的接触角都不低于150°,对油水混合物的分离效率都可达到98%以上,分离时的水通量高达69449 L/(m^(2)·h)以上。经过50次循环分离、酸碱盐溶液腐蚀浸泡8 h、砂纸刮擦30次、高含沙量水冲刷2 h等多项测试后,改性PP织物均保持优异的水下疏油性和大于97%的油水分离效率。从微观结构与化学组成的角度揭示了是表面粗糙度与亲水基团的协同作用使PP织物由最初的疏水亲油转变为超亲水-水下超疏油。[结论]通过化学键连接的方式可以在PP织物表面成功构筑牢固结合的超亲水涂层。该改性过程绿色、简便、低成本,能赋予PP织物优异、耐久的油水分离性能。改性后的PP织物有望在复杂水体环境下的油水分离场景中应用。

[Introduction]Superhydrophilic polypropylene(PP)based materials with high oil-water separation efficiency and excellent durability have good application prospects.[Method]A superhydrophilic-underwater superoleophobic PP fabric was prepared by covalent bonding of carboxymethylcellulose(CMC)to PP fabric.The modified PP fabric was characterized by scanning electron microscopy(SEM),energy-dispersive spectroscopy(EDS),infrared spectroscopy(IR),and X-ray photoelectron spectroscopy(XPS),and its wettability and oil-water separation performance were tested by using a contact angle meter and a home-made oil-water separation device.[Result]The water contact angle of the modified PP fabric was as low as 0°in air,and its contact angle against different oils such as n-hexane,toluene,kerosene,diesel oil,gasoline,and petroleum ether were at least 150°in water.The separation efficiency of the modified PP fabric was at least 98%for different kinds of oil-water mixtures with a water flux higher than 69449 L/(m^(2)·h),and was still 97%above even after 50 cycles of separation,8 hours of immersion in acid,alkali,or NaCl solution,30 times of scratching with sandpaper,and 2 hours of scouring with fine-grained sand in water.The microstructure observation and chemical composition analysis results revealed that the increase of roughness and the presence of hydrophilic groups made the common PP fabric with hydrophobicity and oleophilicity change into a superhydrophilic and underwater superoleophobic material.[Conclusion]A superhydrophilic coating with strong adhesion can be fabricated on the surface of PP fabric by chemical bonding.The modification process with environmental friendliness,simplicity,and low cost can give the PP fabrics excellent and long-lasting oil-water separation performance.The modified PP fabrics are expected to be used in oil-water separation in complex environments.