Hou Jian, Li Bin, Jang Wongi, Yun Jaehan, Eyimegwu Faith M, Kim Jun-Hyun
School of Intelligent Manufacturing, Luoyang Institute of Science and Technology, Luoyang 471023, China.
Henan International Joint Laboratory of Cutting Tools and Precision Machining, Luoyang Institute of Science and Technology, Luoyang 471023, China.
Nanomaterials (Basel). 2023 Jan 19;13(3):416. doi: 10.3390/nano13030416.
This work demonstrates the incorporation of gold nanoparticles (AuNPs) into crosslinker-free poly(N-isopropylacrylamide), PNIPAM, particles and the examination of their structural and catalytic properties. The formation process of the AuNPs across the crosslinker-free PNIPAM particles are compared to that of crosslinked PNIPAM particles. Given the relatively larger free volume across the crosslinker-free polymer network, the AuNPs formed by the reduction of gold ions are detectably larger and more polydisperse, but their overall integration efficiency is slightly inferior. The structural features and stability of these composite particles are also examined in basic and alcoholic solvent environments, where the crosslinker-free PNIPAM particles still offer comparable physicochemical properties to the crosslinked PNIPAM particles. Interestingly, the crosslinker-free composite particles as a colloidal catalyst display a higher reactivity toward the homocoupling of phenylboronic acid and reveal the importance of the polymer network density. As such, the capability to prepare composite particles in a controlled polymer network and reactive metal nanoparticles, as well as understanding the structure-dependent physicochemical properties, can allow for the development of highly practical catalytic systems.
这项工作展示了将金纳米颗粒（AuNPs）掺入无交联剂的聚（N-异丙基丙烯酰胺）（PNIPAM）颗粒中，并对其结构和催化性能进行了研究。将无交联剂的PNIPAM颗粒中金纳米颗粒的形成过程与交联的PNIPAM颗粒的形成过程进行了比较。鉴于无交联剂的聚合物网络中存在相对较大的自由体积，通过还原金离子形成的金纳米颗粒明显更大且多分散性更高，但其整体整合效率略低。还在碱性和醇类溶剂环境中研究了这些复合颗粒的结构特征和稳定性，在这些环境中，无交联剂的PNIPAM颗粒仍具有与交联的PNIPAM颗粒相当的物理化学性质。有趣的是，无交联剂的复合颗粒作为胶体催化剂对苯硼酸的均偶联反应显示出更高的反应活性，并揭示了聚合物网络密度的重要性。因此，在可控的聚合物网络中制备复合颗粒和活性金属纳米颗粒的能力，以及理解结构依赖性物理化学性质，能够推动高度实用的催化体系的发展。
