Research Center for Membrane and Film Technology, Kobe University, 1-1 Rokkodaicho, Nada, Kobe 657-8501, Japan; Department of Chemical Science and Engineering, Kobe University, 1-1 Rokkodaicho, Nada, Kobe 657-8501, Japan; State Key Laboratory of Fine Chemicals, Frontier Science Center for Smart Materials, School of Chemical Engineering, Dalian University of Technology, No.2 Linggong Road, Dalian 116024, China.
Research Center for Membrane and Film Technology, Kobe University, 1-1 Rokkodaicho, Nada, Kobe 657-8501, Japan.
Water Res. 2023 Oct 1;244:120439. doi: 10.1016/j.watres.2023.120439. Epub 2023 Aug 1.
Membrane distillation (MD) has prominent advantages such as treating high-salinity wastewater with a low-grade thermal energy, high salt rejection, and zero discharge. However, organic fouling and mineral scaling are two major challenges for hydrophobic MD membranes when used for practical applications. Commonly, improving organic fouling- and mineral scaling-resistance require oppositely enhanced wetting properties of membrane, thus is difficult to simultaneously realize dual resistance with one membrane. Here, we proposed to use underwater thermodynamically stable high-surface-energy coating to modify the hydrophobic membrane with Janus structures comprising different surface energy. The underlayered structure meets the hydrophobicity requirements of the MD membrane, while the coating layer realizes dual resistance to organic and inorganic foulants. Theoretical analysis and experimental proof reveal that the membrane with the high-surface-energy coating layer outperforms the pristine one with approximately 10 times of longevity. This strategy provides a new way for the use of high-surface-energy materials in versatilely fouling-resistant MD process.
膜蒸馏 (MD) 具有处理高盐废水的低品位热能、高盐截留率和零排放等显著优势。然而，有机污染和矿物结垢是疏水性 MD 膜在实际应用中面临的两大挑战。通常，提高有机污染和矿物结垢阻力需要膜的润湿性具有相反的增强特性，因此很难同时用一种膜实现双重阻力。在这里，我们提出使用水下热力学稳定的高表面能涂层来修饰具有 Janus 结构的疏水性膜，该结构包含不同的表面能。底层结构满足 MD 膜的疏水性要求，而涂层实现了对有机和无机污染物的双重阻力。理论分析和实验证明表明，具有高表面能涂层的膜的使用寿命比原始膜长约 10 倍。该策略为在多功能抗污染 MD 工艺中使用高表面能材料提供了一种新方法。
