基于电场诱导胶束模板法可控构筑有序多孔三维网络吸附剂及其对重稀土吸附性能研究

Three-dimensional network adsorbent shows huge potential application value for the enrichment and separation of precious metal ions due to its faster adsorption rate and higher adsorption capacity. However, to achieve the controllable building of pores and the optimizing design of the network structure is the key factor to affect its application. In this project, the electric-field-directed micelle template was adopted to control the porous structure by the ordered aggregation of micelles in electric field; and the interpenetrating network and nanocomposite structures were constructed to improve the regularity and strength of network. By characterizing the structure of the adsorbent and evaluating its adsorption-desorption behaviors for heavy rare earth ions, the relationship among the porous structure of adsorbent, the network structure and the adsorption-desorption properties was clarified. This is helpful to reveal the electric-field-induced pore-forming mechanism as well as the adsorption/desorption mechanism of rare earth ions on the adsorbents, and to deepen the understanding for the relationship between the internal structures, intrinsic characteristics and external environments, and ultimately achieve a controllable design of porous three-dimensional network adsorbent oriented by function. Rare earth is extremely rare but extremely important strategic resource. The controllable design of porous adsorbent in this study is extremely significant to the establishment of new adsorption/enrichment method and the high-efficient utilization of the scarce rare earth resources.

三维网吸附剂因具有吸附速率快和吸附容量高等优点，在稀贵金属富集和分离领域蕴藏着巨大的潜在应用价值。然而，能否实现吸附剂孔结构的可控构筑和网络结构的优化设计是决定其应用的关键问题。为此，本项目拟采用电场诱导胶束模板法，利用可控电场下胶束的有规聚集调控吸附剂的孔结构；并通过构建互穿网络和纳米复合结构优化网络的规整性和强度，得到孔度可控、网络稳定的三维网络吸附剂。通过表征吸附剂的结构和评价其对重稀土离子的吸附/解吸行为，明确吸附剂孔结构、网络结构与吸附性能之间的关系，揭示电场诱导胶束模板法的成孔机理以及吸附剂对重稀土离子的吸附/解吸机理，加深对吸附剂内部机构、本身特性与外界环境之间相互关系的理解，最终实现功能导向多孔三维网络吸附剂的可控设计。稀土是我国极为稀有但极其重要的战略资源，本研究中多孔吸附剂的可控设计，将对建立稀土高效吸附/富集新方法和促进我国稀缺稀土资源的高效利用具有重要的现实意义。

三维网络吸附剂由于具有吸附速率快、吸附容量高、重复使用性好等优点，在稀贵金属富集和分离领域蕴藏着巨大的潜在应用价值。然而，如何实现吸附剂孔结构的可控构筑和网络结构的优化设计是其应用必须解决的关键问题。为此，本项目采用可控诱导胶束模板和纳米复合法，通过胶束的模板作用调控吸附剂的孔结构；并通过构建纳米复合结构优化网络的规整性和强度，得到了系列孔度可控、结构稳定的三维网络吸附剂。系统表征了吸附剂的结构，评价了吸附剂对稀贵金属离子的吸附/解吸和重复使用性能。结果表明，所制备吸附剂对稀土金属离子Ce(III)、La(III)和Gd(III)的饱和吸附容量分别达到了334.48 mg/g、382.84 mg/g和223.79 mg/g，在重复使用5次后仍能保持90%以上的初始吸附容量。机理研究表明，三维网络吸附剂对稀土金属离子吸附的主要驱动力是化学基团和离子间的络合作用，离子交换和静电作用也对吸附量有贡献。孔道结构有利于提高吸附剂的吸附速率，在20min以内基本达到吸附平衡。此外，该吸附剂对稀贵金属Rb(I)和Cs(I)还表现出了优异的吸附性能。通过构效关系研究，明确了吸附剂孔结构、网络结构与吸附性能之间的关系，揭示了胶束模板法的成孔机理以及吸附剂对稀贵金属离子的吸附机理，理解了吸附剂内部机构、本身特性与外界环境之间相互关系，实现了应用导向多孔三维网络吸附剂的可控设计。稀贵金属是我国极为稀有但极其重要的战略资源，本项目通过系统研究设计了不同结构和组成的多孔三维网络吸附剂，同时拓展研究开发了新型无机介孔功能吸附剂，深入比较了不同类型多孔吸附剂对不同物质的吸附性能，探讨了吸附剂结构与被吸附物结构的关系，筛选出了最优的稀贵金属离子吸附剂，为新型多孔三维网络吸附剂的开发及应用奠定了坚实的理论基础。