特殊浸润性膜的设计制备及高效乳化油水分离性能研究

Membrane separation was known as an effective process with the advantages of easy to operation and low consumption which have been widely used in emulsion oil/water separation. Traditional membrane materials were limited by the poor anti-fouling properties of the oil because of the absorption of oil on the membrane surfaces and inside the pores that resulted in the decreasing of the flux and life of the membrane. Special wetting behaviors of the material surfaces have attracted much attention during the passed decades because of the superhydrophilic-superoleophobic or superhydrophobic-superoleophlic properties of the material surfaces have led to revolution of the oil/water separation process with the high separation efficiency above 99.0%. However, these materials are limited to separating free oil/water mixture because of the larger pore size compared to emulsion droplets. In this project, we proposed a novel method by combining the pore size sieving process with special wetting behavior on the membrane surface. Pore structure, surface roughness and wetting behaviors of the membranes could be tuned though modified phase separation processes or nanostructure template methods, the superhydrophlic-superoleophobic separation membranes could be obtained with the proper pores size compared to emulsion droplets. Owing to the superhydrophilicity-superoleophobicity property, and with ultralow oil adhesion on the rough membrane surface, the water can penetrated quickly through the membrane while oil be separated completely thus leading to high efficient separation of oil/water mixture and emulsion. Combination of special surface wetting behavior and pore size sieve would provide a new way to improve the water flux and finally realize self-dring oil/water emulsion separation with high separation efficiency, moreover, the and the anti-fouling properties of the superwetting membranes during separation process could be greatly improved as well.

膜分离技术具有操作简单及能耗低的特点，在乳化油水分离中具有重要意义和广泛应用。但是传统的分离膜材料在使用中容易吸附油滴造成表面污染及孔道堵塞，降低膜材料的分离效率和使用寿命。特殊浸润性表面及分离材料近年来受到广泛的关注，利用材料表面的超亲水-超疏油或超疏水-超亲油的性质，可以实现分离效率大于99%的油水分离。但现有材料孔径大，适用于大粒径浮油和分散油的分离而难以实现乳化油水分离。本项目提出一种孔径筛分和特殊表面浸润性相结合的的新方法, 通过调控高分子制膜工艺以及以无机纳米结构为模板构建超亲水-超疏油表面的多孔分离膜材料，这种具有超亲水-超疏油及超低油粘附的性质的分离膜能够使水可以迅速通过，而油滴被有效截留，从而实现对油水混合物及乳化油水的高效分离。这种特殊表面浸润性与孔道筛分相结合的方法为提高乳化油水分离通量，实现自驱动或低外压驱动的高效分离以及提升膜抗污染性提供了解决途径。

膜分离技术具有操作简单及能耗低的特点，在乳化油水分离中具有重要意义和广泛应用。但是传统的分离膜材料在使用中容易吸附油滴造成表面污染及孔道堵塞，降低膜材料的分离效率和使用寿命。特殊浸润性表面及分离材料近年来受到广泛的关注，利用材料表面的超亲水-超疏油或超疏水-超亲油的性质，可以实现分离效率大于99%的油水分离。但现有材料孔径大，适用于大粒径浮油和分散油的分离而难以实现乳化油水分离。本项目提出一种孔径筛分和特殊表面浸润性相结合的的新方法, 通过调控高分子制膜工艺以及以无机纳米结构为模板构建超亲水-超疏油表面的多孔分离膜材料，从而实现对油水混合物及乳化油水的高效分离。依据项目计划书的研究计划和任务安排，有序开展了三个方面的研究工作：1. 通过小分子诱导相转化过程构建粗糙表面结构和对高分子材料的成膜过程调控及掺杂交联改性，构建了具有超亲水-超疏油特性的高分子乳化油水分离膜，实现了高效乳化油水分离；2. 以降低膜材料厚度，提升通量为理念设计构建超薄纳米材料薄膜，实现了大通量快速高效的乳化油水分离，并集合表面浸润性调控，实现了对分离膜表面浸润性的双向调控，能够实现油包水、水包油乳液的分离；3. 基于网孔材料的大通量油水分离膜材料制备及直流式油水分离膜过程，通过在大孔基底表面构建抗油粘附微纳结构表面，实现了材料表面对重油的超低油粘附，实现了重油/水的高效率连续稳定分离。对照项目计划书,按照先期计划完成了规定任务。项目执行过程中获得了多种超亲水-超低油粘附性质的多孔分离膜材料，膜的表面显示出超亲水-低油粘附的特性，膜的亲水角<10o, 超疏油，疏油角>150o,可以实现对乳化油水的高效分离；对膜分离性能的检测显示，乳化油水分离的通量>2000 L/m2•h，分离效率>99.9%，抗油污染性能显著提高，主要体现在抗黏附污染方面，膜长效运行效果优良；研究成果在相关领域优质期刊发表影响因子大于3.0的SCI收录的论文7篇，申请专利3项。