Gold Nanoparticle Templated and Catalyzed Formation of Nanopods Using Polymers Bearing Pendant Propargyl Ethers

摘要

Hollow nanostructures have attracted significant interest in recent years due to their unique chemical, physical, and biological properties, which suggest a wide range of applications in drug/gene delivery, imaging, and catalysis. Accordingly, a variety of methods have been developed to synthesize these structures based upon emulsion polymerization, layer-by-layer processes, crosslinking of micelles, molecular or nanoparticle self-assembly, and sacrificial template techniques. Among them, the templating method is particularly powerful in that it transfers the ability to control the size and shape of the template to the product, for which desired homogeneity and morphology can be otherwise difficult to achieve. In this report, we disclose a method for synthesizing polymer nanopods from a linear polymer bearing pendant propargyl ether groups (1), utilizing gold nanoparticles (AuNPs) as both the template for the formation of the shell and the catalyst for the crosslinking reaction (Scheme 1). No additional crosslinking reagents or synthetic operations are required. This novel reaction is both fundamentally interesting and technologically useful. Indeed, it appears to be the first example of AuNP-catalyzed crosslinking of alkyne-based adsorbates, and yields well-defined, homogeneous hollow nanostructures.