Fe3O4/活性炭微纳米颗粒的自组装及其水处理机理研究

The study of preparation techniques of composite structure of iron-based magnetic particles/activated carbon and the exploration of physical mechanism of the composite in water treatment, are an important front problem in magnetic nano-materials. This application project is to use controlled self-assembly of magnetic Fe3O4 nanoparticles to prepare micro/nano composite materials like iron-based/activated carbon or iron-based/diatomite, avoiding the influence of generated secondary pollution sources because of the methods of doping with magnetic precursor or coating with carbon materials. Surface functionalization and compound self-assembly of magnetic nanoparticles will be investigated based on the functional activated carbon or diatomite particles as the carriers. The mechanism of the self-assembly and the synergy effects of the composite materials in water treatment will be revealed. These studies have both the academic value and the potential value of applications. Combining both the physical and chemical techniques, the influence of solvent evaporation rate, interactive forces on nanoparticle surfaces, hydrogen bonding interaction and coupling effect between ligand molecules, humiture, templates, as well as macro force fields on the self-assembly are to be investigated. Taking the commonly-used water-polluted chemical dye rhodamine B as a toxic model substance, the properties and functional mechanisms of pollution cleaning, magnetic separation and recycling of the composite materials are to be clarified. We aim to purify and separate much higher quality water using one cyclic process on the basis of preserving effective pollutant adsorption capacity, adsorption saturation time, and adsorption saturation stability.

研究铁基磁性颗粒/活性炭复合结构材料的制备技术，探索其水处理方面的物理机制，是磁性纳米材料领域的前沿课题。本项目拟通过磁性Fe3O4纳米颗粒可控自组装的方式，制备铁基/活性炭或铁基/硅藻土的微纳米复合材料，避免掺杂磁性前驱体或包被碳材料等易产生二次污染源的影响。开展磁性纳米颗粒表面功能化和以功能性活性炭或硅藻土微颗粒为载体的复合自组装研究，揭示自组装机理和复合材料在水处理方面的协同作用机制，具有重要的学术意义和潜在的应用价值。采用物理和化学方法相结合的方式，研究溶剂挥发速率，颗粒表面作用力，配体分子间氢键、耦合作用以及环境温湿度、模板、宏观力场等对颗粒形成自组装的影响。以常见的水污染染料罗丹明B作为一种毒性模型物质，探明复合材料在水净化、磁分离及循环使用方面的性能及作用机理。在保证污染物吸附性能、吸附饱和时间和吸附饱和稳定性的基础上，实现更纯净的一次性提纯、分离水资源的目标。

磁性纳米颗粒由于合成成本低，单分散性好，具有超顺磁性和易于大量制备等特点，一直备受科研人员关注。基于磁性纳米颗粒的众多应用中，用于水污染处理和磁分离，以及再回收利用的功能性复合纳米材料是当前磁性材料研究领域的前沿课题并涉及城市用水和淡水资源保护等社会、民生需求。本项目通过研究磁性Fe3O4纳米颗粒可控合成，开展了磁性纳米颗粒表面功能化和以功能性活性炭和硅藻土微颗粒为载体的复合颗粒自组装研究，进而成功制备出铁基/活性炭和铁基/硅藻土两种微纳米功能性复合材料。以常见的染料罗丹明B、甲基橙以及铬、铅重金属离子作为典型污染物质，通过批次实验系统地研究了所合成磁性材料在水污染处理、磁分离和循环使用方面的协同效应，并通过普适吸附动力学，吸附等温方程以及热力学相关性质深入地分析了吸附作用机理（包括静电相互作用，氢键，π-π相互作用，介孔填充机制以及Fe3O4纳米颗粒的协同相互作用），结合可见、红外吸收光谱以及电感耦合等离子体光谱等实验数据最终揭示出起关键作用的吸附机制集中于静电作用和协同吸附作用，具有重要的学术意义和潜在的应用价值。