微/纳米结构导电聚合物/粘土复合材料的合成及其吸附重金属离子的构效关系

Due to the infeasibility of decomposition or destruction of heavy metal pollutants, permanent pollution will occur once heavy metal pollutants were discharged into the environment. At present, the pollution problem of heavy metal waste water becomes more and more serious in our country and many physical or chemical methods have also been applied to treat heavy metal wastewater. However, these methods are hard to at the same time satisfy the demands of a technique with all-around excellence such as high efficiency, low cost and no second contamination. In this project, conducting polymer/clay composites with micro/nano-structure and high specific surface areas are prepared by in situ chemical oxidization polymerization during which the polymer acid on the surface of clay platelets is used as dopant of conducting polymer and play a "bridge" role to combine conducting polymer with clay. It is expected to remove the heavy metal ions from wastewater by using conducting polymer/clay composites via the synergy adsorption effect, which is owing to the excellence adsorption characteristics of conducting polymer and clay. The controlled preparation and formation mechanism of micro/nano-structural conducting polymer/clay composites are discussed and their correlations of structure and adsorption behavior for heavy metal ions are also investigated. The results obtained would provide a new preparation approach and basic theory for developing a valuable and applicable adsorption material for heavy metal wastewater.

由于重金属污染物很难被分解和破坏，一旦排入环境将导致永久性污染。目前我国重金属废水的污染问题日渐突出，而现有的物理化学方法，很难同时满足效率高、成本与二次污染低等综合性能俱佳的要求。本项目以粘土表面修饰的高分子酸为"桥"，利用其对导电聚合物的掺杂作用，通过原位化学氧化聚合制备高比表面积微/纳米结构导电聚合物/粘土复合材料；综合导电聚合物与粘土优异的重金属离子吸附特性，实现复合材料对水中重金属离子的协同吸附，净化重金属离子废水；探讨复合材料的可控制备、形成机理及其微/纳米结构与重金属离子吸附性能之间的"构-效"关系，为发展具有应用价值的重金属废水吸附材料提供新颖制备途径与基础理论依据。

为综合导电聚合物与粘土优异的重金属离子吸附特性，实现复合材料对水中重金属离子的协同吸附，本项目以蒙脱土粘土和海泡石粘土为模板，通过原位化学氧化聚合制备了五种微/纳米结构导电聚合物/粘土复合材料，并深入研究了导电聚合物/粘土纳米复合材料对水中重金属离子的吸附性能。主要研究结果如下：(1) 以可聚合多羟基叔胺对蒙脱土进行有机化改性，利用自由基接枝共聚制备聚（2-丙烯酰胺基-2-甲基丙磺酸）改性蒙脱土，通过原位化学氧化聚合可获得具有片状结构的聚苯胺/蒙脱土纳米复合材料，将其用于吸附水中Cr(Ⅵ)离子，表现出优异的吸附性能，且能够进行吸附再生；(2) 以甲基丙烯酰氧乙基-3-甲基氯化铵和甲基丙烯酸的共聚物对蒙脱土进行有机化改性，通过原位化学氧化聚合可制备剥离型聚苯胺/蒙脱土及聚吡咯/蒙脱土纳米复合材料，其对Cr(Ⅵ)离子最大吸附容量分别达到308.6mg/g（聚苯胺/蒙脱土）和166.7 mg/g（聚吡咯/蒙脱土），吸附均符合准二级动力学模型和Langmuir等温模型，且吸附过程是吸热的、自发进行的；(3) 以纤维状海泡石粘土为模板，通过原位化学氧化聚合可制备聚苯胺/海泡石和聚吡咯/海泡石纳米复合纤维，其对Cr(Ⅵ)离子的最大吸附容量可达206.6 mg/g（聚苯胺/海泡石）和302.1 mg/g（聚吡咯/海泡石），且两种纳米复合纤维均能进行吸附再生。通过这些研究工作，发表项目相关SCI收录论文7篇，获授权国家发明专利2项。本项目探讨了复合材料的可控制备、形成机理及其微/纳米结构与重金属离子吸附性能之间的“构-效”关系等关键科学问题，为发展具有应用价值的重金属废水吸附材料提供新颖制备途径与基础理论依据。