大孔交联聚合物基体内富水"微液滴"的构筑及其限域作用

Macroreticular polymer supported metal nanoparticles are potentially excellent catalyst and adsorbent. But severe metal agglomeration often takes place in their liquid phase synthesis, which is due to the spontaneous migration of metal atoms from micro-mesh of polymer matrix to the macro-/mesopores. This problem not only restricts the performance of such materials, but also causes serious waste of resources. Here we expand the confinement effect of liquid/liquid interface into the micro-mesh within the polymer matrix. We can construct water-enriched "microdroplets" based on the selective adsorption of water/organic solvent to hydrophilic group/alkyl skeleton inside the micro-mesh, which may act as nanoreactors to confine the synthesis of nanoparticles. The nanoparticles generated in situ are fastened within the polymer matrix by the micro-mesh, thus the controllable synthesis of macroreticular polymer supported metal nanoparticles can be realized. In this project, we aim to reveal the formation conditions and the microscopic state of the "microdroplet", together with the physico-chemical nature of its confinement effect. We plan to demonstrate the influence of polymer structure-microenvironment of "microdroplet"-rate of redox reaction-metal ion and its counterion-reaction conditions, upon the particle size, morphology, spatial distribution and surface properties of the nanoparticles. Our work is to render scientific basis for controllable synthesis of nanoparticles within macroreticular polymers.

大孔交联聚合物负载型金属纳米粒子在催化/吸附领域具有重要潜能。但在金属纳米粒子的液相合成过程中，金属原子会自发地从聚合物基体中的微网孔向大孔/介孔迁移，导致严重的金属团聚现象。这限制了该类材料潜力的发挥，而且造成严重的资源浪费。申请人拟将液/液界面限域思想拓展到聚合物基体中的微网孔，即利用水/有机溶剂在微网孔内亲水基团/烷基骨架上的选择性吸附，构筑富水"微液滴"纳米反应器来限域合成反应，生成的金属纳米粒子被微网孔原位束缚在聚合物基体中，从而实现大孔交联聚合物负载型金属纳米粒子的可控合成。本项目拟揭示大孔交联聚合物内"微液滴"的形成条件、微观状态及其限域作用的物理化学本质，阐明聚合物结构-"微液滴"微观环境-氧化还原反应速度-金属离子与反离子种类-反应条件等，对生成的纳米粒子粒径、形貌、空间分布以及表面性质的影响规律。本项目的目标是为大孔交联聚合物内纳米粒子的可控合成提供科学基础。

大孔交联聚合物负载型金属纳米粒子具有重要的使用价值。聚合物基体内富水“微液滴”的构筑及其限域作用的研究是这类材料制备和应用的科学基础。本项目阐明了大孔交联聚合物内“微液滴”的形成条件、微观状态及其限域作用的物理化学本质，明确了不同物理化学条件，对生成的纳米粒子粒径、形貌、空间分布以及催化特性等的影响规律。研究内容在原计划基础上进行了调整和拓展，针对纳米粒子催化性能和二氧化碳催化转化反应进行了研究,并取得重要进展。在Nat. Commun., Angew Chem. Int. Ed., Chem. Sci., Green Chem., Chem. Eur. J., ChemcatChem, Langmuir等国际重要期刊发表基金资助研究成果论文16篇，申请中国发明专利3件，其中1件已授权。