Formation of Different Gold Nanocrystal Core鈥揜esin Shell Structures through the Control of the Core Assembly and Shell Polymerization

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• 作者：Zhenhua Sun ; Zhihong Bao ; Caihong Fang ; Jianfang Wang
• 刊名：Langmuir
• 出版年：2012
• 出版时间：June 19, 2012
• 年：2012
• 卷：28
• 期：24
• 页码：9082-9092
• 全文大小：577K
• 年卷期：v.28,no.24(June 19, 2012)
• ISSN：1520-5827

文摘

The formation of different Au nanocrystal core鈥搑esin shell structures through the control of the nanocrystal assembly and shell polymerization is investigated. 4-Mercaptophenol is employed together with formaldehyde as the resin monomers. 4-Mercaptophenol molecules bond to the surface of Au nanocrystals so that the resultant phenolic resin can intimately encapsulate Au nanocrystals. The morphologies of the obtained structures are determined by the nanocrystal assembly and the monomer polymerization behaviors, which are controlled by the solution pH as well as the monomer amounts. At pH = 8鈥?, Au nanorods are assembled and fused together under hydrothermal conditions in a preferential end-to-end manner. The fused structures are coated with a layer of resin, with the thickness controlled by the supplied amounts of the monomers. At pH = 10, Au nanorods are coated with resin of controllable thicknesses and separated from each other. The resin-coated Au nanorods are stable in both aqueous and nonaqueous solutions. At pH = 12, Au nanorods are coated with a thin layer of resin and assembled together in a side-by-side manner. A similar assembly and resin coating behavior is also observed with Au nanopolyhedrons. Moreover, plasmonic鈥揻luorescent bifunctional structures are readily produced by incorporating CdTe nanocrystals in the resin shell that is coated on Au nanocrystals, owing to the presence of a number of thiol groups in the resin shell.