基于Gemini表面活性剂的高内相乳液模板法可控制备多级孔聚合物及其吸附性能研究

At present, water pollution situation is fairly grim in our country. It is helpful to solve the problem to construct high-performance adsorbent of hierarchically porous polymers with large specific surface area and high fluid permeability. This project intends to study the controllable preparation of hierarchically porous monolithic polymer (polyHIPEs) using high internal phase emulsion (HIPE) template mediated by Gemini surfactant (Gemini-S). The strategies of building and adjusting the hierarchical porous structures would be established to optimize the adsorption performance of polyHIPEs. Three series of Gemini-S with various structures would be designed with the aim to study the influence rules of structure parameters including hydrophilic head group, hydrophobic chain, linking group, etc on the HIPE. The related mechanism model would be established based on the experiment results. Porous polyHIPEs could be obtained via initiating polymerization & crosslinking in the continuous phase of HIPE. The rule of adjusting the porous structure of polyHIPEs could be revealed by regulating experiment parameters such as structure and concentration of Gemini surfactant, HIPE composition, porogen, etc. The effect of pore structures of polyHIPEs on the adsorption performance to heavy metal ions would be studied. PolyHIPEs with excellent adsorption performance could be obtained by adjusting the porous structures of polyHIPEs.

我国水污染形势严峻，构筑比表面积大、渗透性高、孔结构可调的高性能多级孔聚合物吸附剂具有重要意义。本项目拟采用基于Gemini表面活性剂(Gemini-S)的高内相乳液（HIPE）模板法，研究多级孔聚合物整体材料（polyHIPEs）的制备及多级孔结构的构建和调控规律，并对其吸附性能进行优化。拟设计、合成三个系列具有不同结构的Gemini-S，系统研究Gemini-S结构包括亲水头基、疏水链、联结基团等对HIPE的影响规律，建立相关机理模型。然后将HIPE连续相进行聚合、交联得到多级孔polyHIPEs，通过改变Gemini表面活性剂结构、浓度、HIPE组成等条件参数，揭示polyHIPEs多级孔结构的调控规律。将制备的多级孔polyHIPEs用于吸附分离污水中的重金属离子等污染物，研究孔结构对其吸附性能的影响规律，通过结构优化，制备出高吸附性能的多级孔polyHIPEs。

表面活性剂是影响高内相乳液(HIPE)模板法制备的聚合物结构和性能的关键因素之一。与传统表面活性剂相比，双子表面活性剂 (Gemini-S)具有更低的临界胶束浓度(CMC)、更高的表面活性以及特殊的流变性质。本项目制备了一系列不同链长的羧酸盐型Gemini表面活性剂(CnNS-SNCn, n=8,10,12,14)，研究了链长对表面活性、HIPE稳定性和聚合物孔结构的影响。随着链长的增加，表面活性剂的CMC逐渐降低，聚合物的孔隙率增加而孔径有缩小的趋势。首次通过Gemini表面活性剂稳定的HIPE模板法制备了系列多级孔聚合物polyHIPEs，对其孔结构进行了系统分析，并用于有机染料MB的吸附。吸附实验表明，与吐温-20相比，Gemini表面活性剂制备的聚合物具有更高的吸附容量和吸附速率，这主要得益于其合理的孔结构。通过HIPE模板法制备了多孔碳材料，重点研究了表面活性剂类型即Gemini表面活性剂与传统型CTAB、TW-20对孔结构的影响规律，发现只有Gemini表面活性剂做乳化剂时制得的聚合物是开孔结构，且碳化后基本保持了前驱体的多孔结构。使用Gemini表面活性剂制备的多孔碳材料的比表面积显著高于其他两种表面活性剂。电化学测试表明，制备的多孔碳SDLC-5AC具有最高的比电容为165.5 F/g。研究了聚苯胺包覆的碳纳米管（PNAI-CNTs）对HIPE模板法制备的多孔碳孔结构的调控。结果表明，PANI-CNTs可以有效调控多孔碳的孔结构和比表面积。