磁性树枝状聚合物功能材料在环境污染物监控中的应用及吸附机制研究

The goal of this project is to synthesize new magnetic dendrimers for developing new and highly effective enrichment and determination methods for typical environmental pollutants, and elucidate their adsorption mechanisms. The easy separation merit of magnetic materials and the unique characteristics such as highly branched structure, monodispersity, terminal groups, terminal and multifunctional groups in the cavity and the designable molecular structure of dendrimers will be fully used to design and prepare functional magnetic nanomaterials. The main interests included: synthesis of magnetic dendrimers by filling with nano zero valent iron or Fe3O4 magnetic material into the cavity of polyamidoamine dendrimers, and thiol group modification and characterization; synthesis of magnetic dendritic polymers with magnetic material as the core and demdrimers as the shell, and modification with amino group, C60, C dots, and beta-CD, etc and characterization; investigation of the adsorption properties of the prepared magnetic material for heavy metals such as mercury, arsenic and cadmium as well as organic pollutants such as bisphenol A, PAH, and PCBs; establishment of series of new analytical methods for pollutants at trace level and elucidation of the adsorption mechanism; synthesis and characterization of magnetic polypropylene-imine polymers; establishment of selective analytical method for trinitrotoluene using the amino groups at the terminal of magnetic dendrimers; development of sensitive methods for the determination of azo-benzene pollutants and aromatic amines based on the principles of photoinduced isomerization interconversion and acid induced structural change. The achievements obtained from this project will provide solid technical foundations and good theoretical references for the development of new detection and control technologies for environmental pollutants and open a new direction for developing novel nanomaterials for the enrichment of pollutants.

本项目拟将树枝状聚合物与磁性材料易分离及树枝状聚合物高度支化的结构和独特的单分散性、端基官能团、端基及空腔的多官能团特性以及可控的分子结构特性有机结合，开发典型污染物痕量富集方法并探讨其吸附机制。重点开展如下研究：以树枝状聚合物空腔内填充磁性材料制备基于聚酰胺-胺的磁性树枝状聚合物及巯基化修饰并表征；以磁性材料为核表面修饰树枝聚合物并进行氨基、C60、碳点、β-CD修饰与表征；考查磁性树枝状聚合物材料的吸附重金属镉、汞、砷及双酚A、PAH、PCB等有机污染物等的吸附性能，建立痕量分析技术并进行吸附机理研究；合成磁性聚丙烯亚胺聚合物并进行表征，建立三硝基甲苯的选择性富集检测技术及采用光致顺-反异构互换原理进行偶氮苯类污染物的富集检测及酸度致结构变化富集苯胺类污染物的新技术。此项目获得的研究成果将为开发高效的环境污染物的检测与控制技术及开发新型富集材料提供坚实的技术基础、理论参考与新思路。

环境污染物的环境安全性一直是环境领域关注的主题，开发高效富集能力的样品前处理技术及检测方法是进行环境污染安全性评价及实时监控的前提，也是环境领域的重要研究方向。本项目的主要研究内容有合成磁性聚酰胺-胺、聚丙烯亚胺树枝状聚合物及其功能化修饰材料并进行表征；基于磁性固相萃取与HPLC-UV 及GC-MS/MS联用,开展典型污染物分析方法研究；开展巯基、MWCNTs、C60、GO等功能化修饰磁性树枝状聚合物材料富集检测典型污染物。通过大量的实验研究，合成了Fe3O4@PAMAM-Gn、Fe3O4@PAMAM-Gn-GO、Fe3O4@PAMAM-Gn-C60、Fe3O4@PAMAM-Gn-4-MBA、Fe3O4@PPI-Gn、Fe3O4@PPI-Gn-GO、Fe3O4@PPI-Gn-C60等系列磁性材料，积累了合成磁性树枝状材料及其功能化修饰的经验及方法；建立了系列检测典型污染物DDTs、酚类、苏丹红、PAHs、重金属离子、PCBs、拟除虫菊酯类杀虫剂的痕量分析方法，并对其吸附机理进行分析，主要归因于氢键、静电作用、π-π共轭相互作用、配位作用等；Fe3O4@PAMAM-Gn对两种酚类的检测限分别为0.017μg/L和0.011μg/L，对三种PAEs的检测限在0.025-0.16μg/L，对苏丹红染料的检测限在0.0018-0.0055μg/L,对DDTs的检测限在0.012-0.029μg/L, Cd(II),Hg(II)的检测限分别为0.016和0.04μg/L, 对PAHs的检测限在0.014-0.055μg/L；功能化材料检测PAHs的检出限在0.19-0.9ng/L及0.22-1.8ng/L之间，检测六种PCBs的线性范围在0.05-20μg/L，检测限在0.015-0.039μg/L。实验结果表明，磁性树枝状聚合物材料对多数典型污染物具有良好的富集能力，可用于开发痕量污染物的检测方法。建立的方法操作简单、分离速度快、灵敏度高，提升了样品分析通量，同时减少了有毒有机溶剂的消耗，具有非常好的推广应用潜力，同时本研究工作为环境污染物的富集材料开发拓展了思路，也为痕量典型污染物的监控提供了良好的分析技术支撑。