pH响应介孔材料表面润湿性的调控及其在油水分离中的抗污染机理研究

Researches show that the hydrophilic oil-water separation film (SSF) with good performance for oily water recycling can be realized through the adjustment of the surface wettability. However, the SSF suffers problems such as easy water absorption and vulnerable to pollution. In addition, the SSF will be polluted by the oil droplets during the oil-water separation process, leading to the decline in the separation velocity and the separation efficiency. Therefore, how to prevent the pollution of the SSF and improve its stability are problems which need to be resolved immediately. In this work, the SSF is decorated by the PAA grafted mesoporous silica, and follow by the surface treatment with fluorine-containing silane coupling agent, and the SSF possessed good anti-fogging property and high efficiency is obtained. The surface wettability can be changed between the hydrophilic and hydrophobic by the pH-response property of the fluoride PAA chains, which is favorable for avoiding the water absorption and the vulnerable to pollution. It is worth noting that the combination of the special structure of the mesoporous material and the amphiphilic fluoride chains will make contributions to the increase of the separation velocity, the separation efficiency and the anti-fogging property during the separation. Based on the adjustment of the surface structure and the composition of the SFF, the relationships among the surface wettability, the separation velocity, the separation efficiency and the anti-fogging property are further investigated, which is helpful for the study of the mechanism of oil-water separation. This work will provide new idea and theoretical basis for the development of the SFF with high efficiency and excellent anti-fogging property.

通过对材料表面润湿性的调控，可以制备性能优良的亲水油水分离网，对含油污水进行回收处理。但是，亲水分离网存在吸水、易受污染等问题，此外，在油水分离过程中油污会污染分离网，导致其分离速度和分离效率的下降。因此，如何防止亲水分离网的污染，提高其稳定性是目前亟需解决的问题。本项目采用聚丙烯酸（PAA）接枝的介孔二氧化硅修饰分离网，并采用含氟硅烷偶联剂对表面进行氟化处理，制备具有抗污染功能的高效油水分离网。利用氟化PAA链段的pH响应特性控制分离网在亲水和疏水之间转换，解决分离网吸水和易受污染等问题；巧妙地将介孔材料的特殊结构和双亲性的氟化链段有机耦合，提高分离网的分离速度、分离效率和抗油污污染性能。通过对油水分离网表面结构和组分的调控，深入研究分离网表面润湿性、分离速度、分离效率以及抗污染性能之间的关系，完善现有油水分离理论机理，为开发高效抗污染的油水分离网提供新方法和理论依据。

针对传统的油水分离网在油水分离过程中易受污染、稳定性差的缺陷，本项目通过引入介孔二氧化硅等多孔材料、调控分离网表面孔径和结构、强化亲水水合层的强度、通过化学键合引入强亲水基团、形成网状多层次交联结构等方式提高油水分离网的在油水分离过程中的抗污染性能与分离的稳定性，所制备的油水分离网具有优异的耐化学试剂和不同pH水滴的稳定性，且耐摩擦性能良好，可以在重复20次的条件下保持油水分离效率大于98%，且最高分离速度33441.6 L·m-2·h-1。研究确定了表面润湿性与分离速度、分离效率和抗油污污染性能的关系，并剖析了其油水分离过程中抗污染的机理，指出油水分离网水合层的强度是影响抗污染的关键因素。此外，针对油水分离网在分离使用后会产生二次污染的难题，通过引入生物基原料、可降解材料、光催化降解无机颗粒等，制备生物基可降解油水分离材料，该材料可以有效分离油水混合物，且可以在大自然中进行降解，解决了传统油水分离材料二次污染的问题。其次，针对高度乳化的油水乳化液以及高粘度的原油污水的分离困难的问题，通过调节分离网结构、引入光热电热颗粒以及引入破乳基团等方式，实现了其有效分离。