Jiang Qian, Wang Yaxin, Xie Yuling, Zhou Ming, Gu Qilin, Zhong Zhaoxiang, Xing Weihong
State Key Laboratory of Materials-Oriented Chemical Engineering, National Engineering Research Center for Special Separation Membrane, Nanjing Tech University, Nanjing 210009, China.
State Key Laboratory of Materials-Oriented Chemical Engineering, National Engineering Research Center for Special Separation Membrane, Nanjing Tech University, Nanjing 210009, China.
Water Res. 2022 Jun 1;216:118270. doi: 10.1016/j.watres.2022.118270. Epub 2022 Mar 9.
Both the pore size and surface properties of silicon carbide (SiC) membranes are demonstrated to significantly affect their separation efficiency when used for oily water treatment. However, the potential influences of open porosity together with the pore size of SiC membranes on their surface properties and oil-water separation performance have rarely been investigated. In this work, porous SiC ceramic membranes with tunable open porosity and pore size were purposely prepared and selected to systematically study the effect of pore structure-dependent wettability on the oil-water separation performance. The measured pure water flux of selected membranes as a function of open porosity (34-48%) and pore size (0.43-0.67 μm) was well-fitted by using a modified H-P equation. Interestingly, the hydrophilicity of SiC membranes was improved with the increase in open porosity and pore size, as evidenced by the gradually decreased dynamic water contact angle and underwater adhesion of oil droplets. Further, the open porosity of SiC membranes was found to contribute more to the improved surface wettability. As a result, the stable flux of SiC membranes in oil-in-water (O/W) emulsions was increased by 24% with the increased open porosity while the oil rejection rate remained above 90%. This work quantitatively reveals the contributions of the pore structure to the surface wettability of ceramic membranes, and thus provides an effective pathway to improve their performance in oil-water separation.
碳化硅（SiC）膜的孔径和表面性质在用于含油污水处理时均被证明会显著影响其分离效率。然而，SiC膜的开孔率以及孔径对其表面性质和油水分离性能的潜在影响鲜有研究。在本工作中，特意制备并选择了开孔率和孔径可调的多孔SiC陶瓷膜，以系统研究与孔结构相关的润湿性对油水分离性能的影响。使用修正的H-P方程能很好地拟合所选膜的纯水通量随开孔率（34%-48%）和孔径（0.43-0.67μm）的变化关系。有趣的是，随着开孔率和孔径的增加，SiC膜的亲水性增强，动态水接触角逐渐减小以及油滴在水下的附着力降低证明了这一点。此外，发现SiC膜的开孔率对改善表面润湿性的贡献更大。结果，随着开孔率增加，SiC膜在水包油（O/W）乳液中的稳定通量提高了24%，而截留率仍保持在90%以上。本工作定量揭示了孔结构对陶瓷膜表面润湿性的贡献，从而为提高其油水分离性能提供了一条有效途径。
