Wang Bingbing, Li Bing, Zhao Bin, Li Christopher Y
A. J. Drexel Nanotechnology Institute and Department of Materials Science and Engineering, Drexel University, Philadelphia, Pennsylvania 19104, USA.
J Am Chem Soc. 2008 Sep 3;130(35):11594-5. doi: 10.1021/ja804192e. Epub 2008 Aug 12.
Despite the great efforts that have been made toward obtaining Janus architectures, synthesizing sub-10 nanometer Janus nanoparticles (NPs) modified with different types of polymers remains a challenging task. In this Communication, "solid-state grafting-to" and "grafting-from" methods were combined to obtain Janus gold NPs (AuNPs) modified with two types of polymer chains on the opposite sides of the NP. We used functionalized polymer single crystals as the solid substrates to immobilize AuNPs. We then used atom transfer radical polymerization to grow polymer chains on the "free" side of the AuNPs. Amphiphilic polyethylene oxide (PEO)-Au-poly(methyl methacrylate), PEO-Au-poly(tert-butyl acrylate) and hydrophilic PEO-Au-poly(acrylic acid) were synthesized. The Janus nature was demonstrated using a platinum-nanoparticle-decoration method. Using polymer single crystals as the reaction substrates is advantageous because they afford higher throughput compared with self-assembled monolayers. Dissolution of the single crystal also leads to NPs with defined polymer patches. We anticipate that our approach could serve as a generic method for synthesizing polymer-functionalized, sub-10 nm Janus NPs. This unique system holds promises for achieving controlled assembly and tunable optic and electronic properties of NPs.
尽管在获取Janus结构方面已付出巨大努力，但合成用不同类型聚合物修饰的亚10纳米Janus纳米颗粒（NPs）仍然是一项具有挑战性的任务。在本通讯中，“固态接枝到”和“接枝从”方法相结合，以获得在NP相对两侧用两种类型聚合物链修饰的Janus金纳米颗粒（AuNPs）。我们使用功能化聚合物单晶作为固体基质来固定AuNPs。然后我们使用原子转移自由基聚合在AuNPs的“自由”侧生长聚合物链。合成了两亲性聚环氧乙烷（PEO）-Au-聚甲基丙烯酸甲酯、PEO-Au-聚（丙烯酸叔丁酯）和亲水性PEO-Au-聚丙烯酸。使用铂纳米颗粒修饰方法证明了Janus性质。使用聚合物单晶作为反应底物具有优势，因为与自组装单分子层相比，它们具有更高的通量。单晶的溶解还会产生具有确定聚合物斑块的NPs。我们预计我们的方法可作为合成聚合物功能化的亚10纳米Janus NPs的通用方法。这个独特的系统有望实现NPs的可控组装以及可调谐的光学和电子性质。
