基于多组分点击化学构筑超亲水/超疏油表面及乳液分离材料的研究

“Water-removing” materials with superhydrophilic/superoleophobic surface provide an ideal solution for the pollution of emulsified oily wastewater because of their anti-fouling, self-cleaning and highly efficient properties. However, superhydrophilic/ superoleophobic surface is an “abnormal” wetting phenomenon, and the contradiction between superhydrophilic and superoleophobic properties becomes the critical bottleneck and long-term challenge in this field. We have recently found that click reactions served an efficient tool to couple substrate with fluorine-containing compounds with low surface energy for construction of hydrophobic/oleophobic surface. This finding provides an enlightenment: if a compound with double- functionalization property could react with two different kinds of groups while maintaining the efficiency of click chemistry, superhydrophilic and superoleophobic properties might coexist. Therefore, we propose to introduce thiolactone groups with the properties of double-modification, click attribute and multi-component reaction to the surface of cotton fabrics, and control them to successively react with highly polar groups and non-polar groups with low surface energy. As a result, the surface with hydrophilic segments and oleophobic segments would become a binary nanoscale interface, and the superhydrophilic/ superoleophobic properties achieve a balance. The coupling efficiency of thiolactone multicomponent click reactions to the highly polar groups and non-polar groups with low surface energy will be investigated, and the design guidelines for superhydrophilic/ superoleophobic surface will be established to realize the controllable adjustment of superhydrophilic and superhydrophobic properties. Finally, the new preparation methods for superhydrophilic/ superoleophobic materials will be developed. This project will provide fundamental theory and technical support for superhydrophilic/ superoleophobic interface and materials.

超亲水/超疏油“去水型”分离材料以其高抗污、自清洁、高效率等优点成为解决乳化含油废水污染的理想选择，但由于超亲水/超疏油是“反常”润湿表面，两种性质难以共存的矛盾成为该领域的瓶颈。课题组前期研究发现巯基点击化学能够高效偶联含氟单体、构筑疏水/疏油表面，而具有两次功能化特性的点击反应能够实现对两种不同基团的高效偶联，有望为解决超亲水与超疏油的共存提供有效方案。本课题拟在织物表面引入具有两次功能化和多组分反应特性的硫代内酯基团，进一步对高极性基团和低表面能基团进行顺序偶联，使表面同时含有亲水链段和疏油链段并达到二元协同纳米界面的效果，促进相互制约的矛盾达到合理平衡。探究硫代内酯对高极性和低表面能非极性两类基团的高效偶联方法，提出基于硫代内酯化学构筑超亲水/超疏油型分离材料的设计原则，实现超亲水与超疏油的可控调节，并建立“去水型”分离材料的制备新技术，为这类材料的应用提供理论指导和技术储备。

针对油水分离材料界面精确调控的难题，本项目利用具有一锅多组分反应特性的硫代内酯化学为平台，采用多种功能化方法制备了一系列不同浸润特性的纤维素和聚硫醚，研究其对油水混合液、油水乳液及油油混合液的分离效率，最后探究了表面特性精确可控的纤维素和聚硫醚在油水界面和油油界面的浸润特性和稳定作用。主要研究内容如下：.（1）首先设计、合成了一系列功能化硫代内酯单体，优化了反应条件，实现了三种硫代内酯功能化单体的高效批量制备，建立了硫代内酯两次功能化的反应平台，为后续结构设计和性能调控奠定了基础。同时，探索了硫代内酯多组分点击化学在聚氨酯结构调控上应用，制备了双交联的高性能聚氨酯弹性体和双离子液体功能化的导电弹性体，硫代内酯化学的两次功能化特性在材料结构调控和性能增强具有巨大应用潜力。.（2）通过多种功能化方法制备了亲油疏水型和亲水疏油型纤维素，并对其表面浸润性和油水分离性能进行了研究。烷基化改性滤纸、纤维素颗粒和脱脂棉均具有优异亲油疏水性、化学稳定性、油水分离效率和循环稳定性，同时其对低界面张力(≤3 mN/m)的有机溶剂体系也有出色分离性能。基于上述优点，烷基化改性纤维素将在油水分离、油油分离和界面润湿与稳定等领域展示其巨大应用潜力。此外，利用硫代内酯多组分反应特性成功制备了亲水疏油两次功能化滤纸，改性滤纸具有响应性亲水疏油表面，但其疏油性能和油水分离效率仍需进一步提升。.（3）通过改变烷基链长制备了一系列表面疏水性精确可调功能化纤维素和聚硫醚，实现了对极低界面张力溶剂体系（极性溶剂和非极性溶剂）的选择性浸润，并成功用于不同类型无水乳液（极性包非极性、非极性包极性乳液）的界面稳定。基于功能化纤维素和聚硫醚稳定无水乳液平台，成功利用水敏感异氰酸酯界面聚合制备了聚合物微球和微胶囊。本工作为无水乳液稳定剂提供了高效的制备方法和可调的结构设计，有望进一步推动该领域的发展。