Template-controlled synthesis of wire-like cadmium sulfide nanoparticle assemblies within core-shell cylindrical polymer brushes

A controlled fabrication of wire-like assemblies of cadmium sulfide (CdS) nanoparticles has been developed based on a template technique. Well-defined amphiphilic core-shell cylindrical polymer brushes were used as single molecule templates, utilizing the coordination of cadmium ions with carboxylate groups in the core of the brush. Formation of CdS nanoparticles inside the polymer brush was carried out via the reaction of the coordinated Cd2+ ions with H2S. This route resulted in wire-like CdS nanoparticle assemblies of about 4-5 nm in diameter and about 170 nm long. After the formation of the CdS nanoparticles, the polymer brush resumes its original chemical structure and morphology and therefore can be used as template again. The obtained polymer-semiconductor nanocomposite is soluble and stable in organic solvents, and potential applications may be found due to the quasi-1D structure of the assembly of CdS nanoparticles. In principle, the present synthetic approach is of general applicability to various metals, metal chalcogenides, and oxides.