双重仿生构筑亲疏复合结构油水分离膜及其聚结-转移-导流机制研究

航空燃油中微纳乳化水的高效分离对保障飞行安全有着重要意义。基于传统“亲水聚结”或“疏水筛分”机制的油水分离膜具有分离能耗高、易被乳化水滴堵塞等缺点。本项目提出一种基于“聚结-转移-导流”过程的新机制，其核心是通过构建具有亲水锥形阵列和疏水多孔的双极结构膜，促进乳化水在膜上的持续更新，降低水滴的停留时间，实现油中微纳乳化水高效分离的同时降低压降。具体内容包括：1）研究微液滴在锥形结构上的聚结转移行为和在亲/疏界面处的移动行为规律，揭示影响“聚结-转移-导流”机制的关键因素及调控方法；2）对分离过程中油水两相的流动行为进行计算流体力学数值模拟，结合实验，获得亲水锥形-疏水多孔复合结构的表面特征、流体力学行为和油水分离性能三者之间的内在联系，指导复合膜结构的优化。本项目的实施能够促进油水液-液两相在油-水-固界面分离理论的发展，为高效率、低能耗的油水分离膜的设计与开发提供新的思路。

The high-efficiency separation of micro-/nano- emulsified water in the aircraft fuel is of great significance to ensure the safety of flying. The traditional hydrophilic or hydrophobic oil/water separation membranes based on coalescence or size-sieving mechanism are of high energy consumption and easily blocked by emulsified water. This project aims to fabricate a membrane integrating hydrophilic cone arrays and hydrophobic porous structures, which functioning under a novel coalescence-transfer-drainage operational mechanism. The core concept is to combine hydrophilic cone array structures on a porous hydrophobic membrane, creating a bipolar structure, which could facilitate the removal of the coalesced water on the surface of the membrane efficiently and reduce the separation energy consumption. The detailed research aspects are as follow: 1) to investigate the coalescence and moving behavior of the micro-droplets on the cone structure and at the hydrophilic/hydrophobic interface, and reveal the key factors and control methods regarding the coalescence-moving-drainage mechanism; 2) to simulate the oil-water two-phase flow behavior during the separation by computational fluid dynamics (CFD) method, and combining the experimental data, summarize the relations among the surface characteristics of the complex hierarchical structure, the hydrodynamic behavior and the oil-water separation performance, which would give guidance for the membrane structure optimization. This project can benefit the development of the oil/water separation theory, and provide new thoughts for designing the future oil/water separation membrane with high efficiency and low energy consumption.