电响应型智能膜的调控机理与在水处理中的应用研究

Conventional membranes have two key limitations: transport and selectivity of these polymer barriers are controlled by properties fixed during or after fabrication; they become fouled and cannot have their transport properties tuned in-situ. In this regard, the need for developing a tuneable membrane, which transport properties can be changed in-situ with self-cleaning performance, is certainly warranted. The overall aim of this research is to develop unique conducting membranes with high conductivity, good mechanical strength and stable electrical response using electroactive conducting polymers. In terms of smart separation, the stimuli responsive membrane can be electrically tuned to achieve different fluxes and selectivity. In terms of anti-fouling behavior, the stimuli responsive membrane can allow the fouling layer to be pushed off/through membranes by application of external potential. The target application is in the wastewater with organic pollutants and heavy metal ions. The stimuli responsive membrane can achieve the removal of organic pollutants as well as separation and recovery of heavy metals by combining electrochemical oxidation and membrane separation through adjusting its redox state under the application of applied potential. This research will develop the novel stimuli responsive membrane with tuneable separation and anti-fouling properties and will be looking to provide fundamental proof for the application of the membrane in the treatment and recycle of wastewater.

传统的膜材料在制备成膜后，膜的选择透过性无法自主调控，应用过程中难以对膜实现在线智能化控制。此外，膜污染仍然是制约传统膜技术广泛应用的主要因素。因此，开发智能化的新型膜材料，研发可在线自主调控以及具有自清洁功能的膜成为必然趋势。本研究拟开发电响应智能膜，以具有电活性的导电高分子为膜材料，制备导电性能好、机械强度高、电响应性能稳定的导电膜。拟采用外加电压调控高分子链的结构，对膜的选择透过性进行可控调节，实现对膜分离过程的智能性调控。针对膜污染问题，拟通过电压改变膜与污染物的相互作用，达到在线缓解膜污染的目的。针对高有机、高重金属废水，拟采用电化学协同膜分离技术，凭借电响应膜特有的氧化还原特性，促进有机物的降解去除，并实现对重金属的分离回收。本工作将制备出兼具电响应智能分离和抗污染功能于一体的导电膜，并为电响应膜在污水处理与资源化方面的推广应用提供重要依据。

传统的膜材料在制备成膜后，膜的选择透过性无法自主调控，应用过程中难以对膜实现在线智能化控制。此外，膜污染仍然是制约传统膜技术广泛应用的主要因素。因此，开发智能化的新型膜材料，研发可在线自主调控以及具有自清洁功能的膜成为必然趋势。本研究通过开发电响应智能膜，以具有电活性的导电高分子聚苯胺为膜材料，制备了导电性能好、机械强度高、电响应性能稳定的导电膜。通过外加电压调控高分子链的结构，对膜的选择透过性进行可控调节，实现对膜分离过程的智能性调控。针对膜污染问题，施加负偏压后，可显著缓解膜通量的下降。膜表面污染层形貌分析表明，施加电压有利于膜表面形成更加疏松的污染层结构。进一步采用XDLVO理论对膜与污染物之间的作用力进行分析发现，施加电压能够提高膜表面的相对电势，增强膜对污染物的排斥力，达到在线缓解膜污染的目的。针对高有机废水，采用电化学过滤方式，在施加2.5 V槽压，对亚甲基蓝（MB）、甲基橙(MO)、苯酚(PhOH)三种模式污染物的降解去除率可达94.9%、96.1%、95.6%，远高于传统的电化学氧化过程。本研究为电响应智能膜在污水处理与资源化方面的推广应用提供重要的依据。