Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-Ro, Nam-Gu, Pohang 790-784, the Republic of Korea.
Nanoscale. 2018 Feb 8;10(6):3037-3045. doi: 10.1039/c7nr08199e.
Oil spills and an increasing demand for the treatment of industrial oily wastewater are driving the need for continuous large-scale oil/water separation processes. Herein, we report a nanofibrous cellulosic membrane (NFC membrane) for the continuous high-flux separation of large amounts of oil/water mixtures. The NFC membrane was fabricated using wet electrospinning, a facile yet effective method for stacking nanofibrous membranes with uniform porous structures on a substrate. Owing to its cellulosic nature, the membrane showed excellent underwater superoleophobicity along with robust chemical stability and was able to separate oil/water mixtures at efficiencies exceeding 99%. Repetitive oil/water separations could be performed using a single membrane, during which the oil content in the filtrate remained extremely low (<29 ppm). The nanofibrous membrane exhibited a fine porous structure that was interconnected throughout the membrane, resulting in a high oil intrusion pressure (>30 kPa) that allowed not only gravity-driven but also pressure-driven separation of oil/water mixtures. The separation flux reached 120 000 L m h during pressure-driven separations, which is a very promising feature for actual applications such as the large-scale treatment of industrial oily wastewater.
石油泄漏以及对处理工业含油废水需求的不断增加，推动了对连续大规模油水分离工艺的持续需求。在此，我们报告了一种用于连续高通量分离大量油水混合物的纳米纤维纤维素膜（NFC 膜）。NFC 膜是通过湿法静电纺丝制备的，这是一种简单而有效的方法，可以在基底上堆叠具有均匀多孔结构的纳米纤维膜。由于其纤维素性质，该膜在水下表现出优异的超疏油性，同时具有强大的化学稳定性，能够以超过 99%的效率分离油水混合物。使用单个膜可以进行重复的油水分离，在此期间，滤液中的含油量仍然极低（<29 ppm）。纳米纤维膜具有精细的多孔结构，整个膜内相互连通，导致高油侵入压力（>30 kPa），不仅允许油水混合物在重力驱动下分离，还允许在压力驱动下分离。在压力驱动分离过程中，分离通量达到 120000 L m h，这对于实际应用（如大规模处理工业含油废水）来说是一个非常有前景的特性。
