聚多巴胺-埃洛石纳米管改性不锈钢网及其油水分离性能

Polydopamine-halloysite nanotubes modified stainless steel mesh and its oil-water separation performance

工业含油废水的大量产生和漏油事故的频发,促使高效处理含油废水成为全球性问题。通过浸渍法将聚多巴胺(Polydopamine,PDA)和埃洛石纳米管(Halloysite nanotubes,HNTs)原位沉积在不锈钢网上,制备了超亲水/水下超疏油滤网(PDA-HNTs/SSM)并用于油水分离。利用SEM、EDS、FTIR、XRD、XPS和接触角仪表征了改性不锈钢网的表面形貌、化学组成和润湿性。结果表明,通过调整PDA与HNTs的浸渍周期可控制材料的润湿性和表面微/纳复合结构,10个浸渍周期得到的PDA-HNTs/SSM的超亲水性/水下超疏油性能最优,水下二氯甲烷接触角大于157°,滑动角小于5°。分别采用二甲苯、环己烷、正己烷、石油醚和二氯甲烷进行油水分离测试,PDA-HNTs/SSM的分离效率均大于99%,经50次循环使用后其分离效率在95.5%以上,且在浓度为1 mol/L的HCl、NaOH和NaCl溶液中静置7天或经砂纸摩擦10 m后,仍保持稳定的水下超疏油性和良好的油水分离能力。

The massive generation of industrial oily wastewater and the frequent occurrence of oil spills have caused efficient treatment of oily wastewater to emerge as a global challenge.A superhydrophilic/underwater superoleophobic stainless mesh(PDA-HNTs/SSM)was conveniently fabricated by in-situ immersion of polydopamine(PDA)and halloysite nanotubes(HNTs)and used for oil-water spearation.The surface morphology,chemical composition and wettability of the modified SSM were analyzed by SEM,EDS,FTIR,XRD,XPS and contact Angle instrument.The results showed that the wettability and surface micro-nano hierarchical structure of PDA-HNTs/SSM can be controlled by immersion times of PDA-HNTs.PDA-HNTs/SSM obtained by immersion for 10 times had the best wetting performance,the contact angle underwater of dichloromethane was 157°,and the sliding Angle is less than 5°.Dimetylbenzene,cyclohexane,n-hexane,petroleum ether and dichloromethane were used for oil-water separation test.The separation efficiency of PDA-HNTs/SSM was more than 99%,and still maintained above 95.5%after 50 cycles.Moreover,after standing in 1 mol/L HCl,NaOH and NaCl solution for 7 days or rubbing with sandpaper for 10 m,PDA-HNTs/SSM still maintained stable underwater superhydrophobility and good oil-water separation ability.