Sun Cheng-Hao, Septani Cindy Mutiara, Sun Ya-Sen
Department of Chemical and Materials Engineering, National Central University, Taoyuan 32001, Taiwan.
Langmuir. 2021 Jan 19;37(2):636-645. doi: 10.1021/acs.langmuir.0c02298. Epub 2021 Jan 4.
Bowl-like nanostructures have attracted significant scientific and technological interest due to their favorable characteristics, such as high specific surface area, interconnected porous channels, and conductivity. However, tailored synthesis of bowl-like nanostructures with well-defined and uniform morphology is still a challenge. Herein, we report a versatile microemulsion assembly approach to prepare bowl-like nanostructures of three different materials: polymer, carbon, and platinum. To this end, polystyrene--poly(4vinylpyridine), PS--P4VP, block copolymer (BCP) microparticles with truncated-sphere shape and composed of stacks of parallel lamellae were used because those anisotropic microparticles play an important role in the design of bowl-like nanostructures. To form nanolamellae-within-microparticle morphology, a designed PS--P4VP/chloroform/CTAB microemulsion can be facilely obtained in the aqueous medium, where the morphology can be tailored by the interplay between macro-phase separations, BCP self-assembly, and interfacial energies of three phases in the presence of cetyltrimethylammonium bromide (CTAB). Finally, protonation or combination of cross-linking and pyrolysis of those truncated microparticles enables formation of polymer or carbon bowl-like nanostructures, respectively. Upon selective adsorption of Pt precursor salt ions with the pyridyl moieties followed by chemical reduction, subsequent calcination permits the synthesis of Pt bowl-like nanostructures. The microemulsion assembly approach opens up new ways to direct and template bowl-like nanostructures.
碗状纳米结构因其具有诸如高比表面积、相互连接的多孔通道和导电性等良好特性，而引起了重大的科技关注。然而，定制合成具有明确且均匀形态的碗状纳米结构仍然是一项挑战。在此，我们报告一种通用的微乳液组装方法，用于制备三种不同材料（聚合物、碳和铂）的碗状纳米结构。为此，使用了由平行薄片堆叠组成的截头球形聚苯乙烯 - 聚（4 - 乙烯基吡啶）（PS - P4VP）嵌段共聚物（BCP）微粒，因为这些各向异性微粒在碗状纳米结构的设计中起着重要作用。为了形成微粒内纳米薄片形态，在水介质中可以轻松获得一种设计的PS - P4VP/氯仿/CTAB微乳液，在十六烷基三甲基溴化铵（CTAB）存在下，通过宏观相分离、BCP自组装和三相界面能之间的相互作用可以调整其形态。最后，对那些截头微粒进行质子化或交联与热解相结合，分别能够形成聚合物或碳碗状纳米结构。在用吡啶基部分选择性吸附铂前驱体盐离子并进行化学还原后，随后的煅烧允许合成铂碗状纳米结构。微乳液组装方法为指导和模板化碗状纳米结构开辟了新途径。
