双功能CD@PEI多孔材料的制备及对水中复合微污染物的吸附研究

The coexistence of organic-inorganic micropollutants often results in joint toxicity and carcinogenicity, which has great potential ecological and health threats. Therefore, it is of great significance to study the removal of complex micropollutants in water. The project intends to prepare bifunctional CD@PEI porous materials with high adsorption and separation efficiency for organic and inorganic micropollutants, utilizing the excellent properties of cyclodextrin (CD) inclusion and the non-covalent bond interaction between cyclodextrin molecules, using the easily functionalization of crosslinkers, and combining with the strong chelating ability of polyethylenimide (PEI). CD will be modified to obtain cyclodextrin monomers with strong inclusion and reaction activity. According to the mechanism of metal adsorption and the rigid precursor mechanism of porous polymer synthesis, aromatic compounds will be employed as cross-linking agents. The cross-linker will be prepared by introduction of functional groups containing heteroatoms S/N/O/P. PEI will be introduced as another monomer. The new adsorbent with strong adsorption capacity will be prepared and optimized through self the assembly form by cross-coupling reaction. The relationship between the structure and properties of materials will be explored through the study of adsorption mechanism. The synthesized porous materials will be used as solid phase adsorbents for the removal of phenols, small molecule drugs, heavy metals and other complex micro-pollutants in water, in order to obtain a new and efficient technology for the removal of mixed micropollutants.

有机-无机微污染物共存，往往会产生联合毒性和致癌性，具有较大潜在生态和健康威胁性。故研究水中复合微污染物的去除具有重大意义。项目拟利用环糊精(CD)的优异包合性能和环糊精分子间非共价键相互作用，利用交联剂易于功能化修饰，结合聚乙烯亚胺(PEI)强螯合能力，制备一种对有机无机微污染物具有高效吸附分离的双功能CD@PEI多孔材料。对CD进行改性，获得包合作用和反应活性都较强的环糊精聚合单体；以芳香环骨架化合物作为刚性前驱体，基于金属吸附机理，对交联剂进行功能化设计，获得含N/O/S/P等功能基团的刚性交联剂；引入PEI作为另一种聚合单体，通过交叉偶联反应进行自组装并优化合成条件，制备具有强吸附能力的新型吸附剂。通过吸附机理研究，探索材料结构与性能的构效关系。将合成的多孔材料作为固相吸附剂，应用于水中酚类、小分子药物类、重金属等复合微污染物的去除，以期获得一种新型高效的混合型微污染物去除新技术。

有机-无机微污染物共存，往往会产生联合毒性和致癌性，具有较大潜在生态和健康威胁性。本项目利用环糊精(CD)的优异包合性能和环糊精分子间非共价键相互作用，结合聚乙烯亚胺(PEI)强螯合能力，制备了一种对有机无机微污染物具有高效吸附分离的双功能CD@PEI多孔材料，同时拓展了其他新型环糊精聚合物的制备与吸附性能研究。以三聚氰氯为交联剂，以β-环糊精和聚乙烯亚胺为交联对象，采用两步法制备了CD@TCT@PEI吸附剂，可同时有效地去除废水中对苯二酚和铅离子；CD@TCT@PEI对两者吸附的最佳pH值正好在常规废水pH范围内，减少了废水处理时调节pH值的步骤；CD@TCT@PEI对对苯二酚的吸附速率很快，在5min内可达到79.9%的吸附率；CD@TCT@PEI在25℃下对Pb(II)和对苯二酚的最大吸附量分别是113.52mg/g和364.86mg/g；温度对Pb(II)和HQ的吸附影响较小，吸附量随温度的升高而下降，属于自发、放热、熵增的过程；材料对对苯二酚的吸附机理主要包括环糊精的包合作用和氢键作用，对铅离子的吸附机理是静电引力和配位螯合机理。以六亚甲基二异氰酸酯为交联剂，以环糊精和TTSBI(5,5',6,6'-四羟基-3,3,3',3'-四甲基螺旋双茚)为交联对象，制备了CD@TTSBI材料；该材料能够快速高效地吸附水中双酚A和双酚S，对50.4mg/LBPA和52mg/LBPS的吸附均能够在1.5min时达到吸附平衡，BPA和BPS的最大吸附量（Sips等温线拟合值）分别为554.76mg/g和629.6mg/g。制备了四种环糊精聚合物，用于3种双酚类、6种硝基苯类、4种萘类化合物的吸附去除；制备了一种TosylCD@PEI聚合物，用于对苯二酚的吸附去除；制备了一种CHITOSAN@CD聚合物，用于双酚A和金离子的吸附去除。上述材料均具有优秀的重复利用性能。本项目研究内容和结果为新材料的合成和拓展应用提供理论基础。