纤维素/陶瓷复合膜的制备及油水分离性能研究

Preparation and Oil-Water Separation Properties of Cellulose/Ceramic Composite Membrane

目的提高陶瓷膜对水包油乳化液的分离能力。方法将纤维素粉末充分溶解在氢氧化钠、尿素、水配制的溶解液中,低温真空下在多孔陶瓷分离膜表面构筑亲水性纤维素涂层。通过X射线衍射仪(XRD)、场发射扫描电子显微镜(SEM)、接触角测量仪、紫外-可见分光光度计表征纤维素/陶瓷复合膜的组成、结构、表面润湿性及水包油(甲苯)乳液分离效率。结果纤维素成功复合到多孔陶瓷膜孔隙表面,空气中水滴在膜表面的接触角为0°,水中油滴的接触角高达155°左右,使多孔陶瓷膜具备了在空气中超亲水-水下超疏油的特性。通过油水分离实验发现,在常温常压下,多孔陶瓷膜对水包甲苯乳液高效分离,其油水分离能力(>99.26%)、抗污染性(经20次循环分离后,三种复合的平板陶瓷膜的水通量变化不大)得到显著提高,表现出较好的油水分离性能。结论陶瓷分离膜经纤维素修饰后,表面亲水性和水下超疏油性都得到了提高,油水分离能力可达99.26%,重复使用20次的纯水通量无明显衰减。

The work aims to improve separation capacity of ceramic membrane to oil/water emulsion. Cellulose powder was fully dissolved in the solution of sodium hydroxide, urea and water, hydrophilic cellulose coating was constructed on porous ceramic membrane in vacuum at low temperature. Composition, structure, surface wettability and separation efficiency of water-in-oil（toluene） emulsion was characterized with X-ray diffractometer（XRD）, field emission scanning elec-tron microscope（SEM）, contact angle measuring instrument and ultraviolet-visible spectrophotometer. The cellulose was successfully compounded into surfaces of porous ceramic membrane pores. Contact angle of water droplets on the membrane in air was 0°, and that of oil droplets in water was up to 155°, which endowed porous ceramic membrane with super-hydrophilicity in air and underwater super-lipophobicity. Oil-water separation experiment showed that the porous ceramic membrane exhibited high efficiency in separating toluene-in-water emulsion at normal temperature and pressure. Its oil-water separation capability（ 99.26%） and anti-fouling performance（water flux of three composite flat ceramic membrane changed slightly after separation for 20 times） were improved significantly. The membrane showed good oil-water separation performance. Surface hydro-philicity and underwater super-lipophobicity of ceramic separation membrane are improved by cellulose modification. The oil-water separation capability reaches 99.26%, and pure water flux exhibits no obvious attenuation after repeated use for 20 times.