A method for stabilizing colloidal suspensions of nanocrystals or nanoparticles in a solvent or solid matrix is provided by coating the nanocrystals with bulky organic molecules, specifically dendrons. By coating nanocrystals with a dense organic dendron coat and further cross-linking the dendron ligands, oxidation of the nanocrystals and dissociation of the ligands are avoided. This invention allows nanocrystals to undergo rigorous purification and processing. It may regularly be applied to a variety of nanocrystals.
CROSS-REFERENCE TO RELATED APPLICATIONS
This U.S. utility Patent Application claims priority to U.S. Provisional patent application 60/290,541, filed on May 14, 2001.
Composite particles of a semiconductor particle such as a metal chalcogenide within a crosslinked, cored dendrimer are described. Additionally, methods of making the composite particles and compositions that contain the composite particles are described.
Dendron ligands or other branched ligands with cross-linkable groups were coordinated to colloidal inorganic nanoparticles, including nanocrystals, and substantially globally cross-linked through different strategies, such as ring-closing metathesis (RCM), dendrimer-bridging methods, and the like. This global cross-linking reaction sealed each nanocrystal within a dendron box to yield box-nanocrystals which showed dramatically enhanced stability against chemical, photochemical and thermal treatments in comparison to the non-cross-linked dendron-nanocrystals. Empty dendron boxes possessing a very narrow size distribution were formed by the dissolution of the inorganic nanocrystals contained therein upon acid or other etching treatments.
Composite particles of a metal particle within a crosslinked, cored dendrimer are described. Additionally, methods of making the composite particles and compositions that contain the composite particles are described.
Fabrication and arrangement of nanoparticles into one-dimensional linear chains is achieved by successive chemical reactions, each reaction adding one or more nanoparticles by building onto exposed, unprotected linker functionalities. Optionally, protecting groups may be used to control and organize growth. Nanoparticle spheres are functionalized in a controlled manner in order to enable covalent linkages. Functionalization of nanoparticles is accomplished by either ligand exchange or chemical modification of the terminal functional groups of the capping ligand. Nanoparticle chains are obtained by a variety of connectivity modes such as direct coupling, use of linker molecules, and use of linear polymeric templates. In particular, a versatile building block system is obtained through controlled monofunctionalization of nanoparticles.
