Solomon Brian R, Hyder Md Nasim, Varanasi Kripa K
Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge MA 02139.
Sci Rep. 2014 Jul 1;4:5504. doi: 10.1038/srep05504.
Membranes that separate oil-water mixtures based on contrasting wetting properties have recently received significant attention. Separation of nanoemulsions, i.e. oil-water mixtures containing sub-micron droplets, still remains a key challenge. Tradeoffs between geometric constraints, high breakthrough pressure for selectivity, high flux, and mechanical durability make it challenging to design effective membranes. In this paper, we fabricate a hierarchical membrane by the phase inversion process that consists of a nanoporous separation skin layer supported by an integrated microporous layer. We demonstrate the separation of water-in-oil emulsions well below 1 μm in size. In addition, we tune the parameters of the hierarchical membrane fabrication to control the skin layer thickness and increase the total flux by a factor of four. These simple yet robust hierarchical membranes with engineered wetting characteristics show promise for large-scale, efficient separation systems.
基于不同润湿性来分离油水混合物的膜最近受到了广泛关注。纳米乳液（即含有亚微米级液滴的油水混合物）的分离仍然是一个关键挑战。几何约束、用于选择性的高突破压力、高通量和机械耐久性之间的权衡使得设计有效的膜具有挑战性。在本文中，我们通过相转化过程制备了一种分级膜，该膜由集成微孔层支撑的纳米多孔分离皮层组成。我们展示了对尺寸远低于1μm的油包水乳液的分离。此外，我们调整分级膜制备的参数以控制皮层厚度，并将总通量提高了四倍。这些具有工程化润湿性的简单而坚固的分级膜有望用于大规模高效分离系统。
