Metal-mediated reversible self-assembly of carbon nanotubes

Abstract

There is provided a method and nanocomposite for the reversible assembly of nanotubes, such as oxidized single wall carbon nanotubes, based on metal coordination. The method produces a thermally stable, neutral nanocomposite possessing enhanced mechanical, electrical, physical and chemical properties for example. Disassembly can be provided by treatment with a competing ligand compound.

What is claimed is: 
     
         1 . A method of preparing a nanocomposite, the method comprising the steps of: reacting first and second nanotubes with a metal complex in a solvent system to form an assembled complex, wherein the metal complex is comprised of a metal and a ligating portion selected from monotopic, ditopic and polytopic ligands coordinated to the metal, and wherein each of the first and second nanotubes includes at least one ligating component coordinating with the metal such that the metal complex serves to connect the first and second nanotubes. 
     
     
         2 . The method of  claim 1 , where the assembled complex is disassembled upon treatment with a competing ligand component. 
     
     
         3 . The method of  claim 1 , where the nanotubes are selected from the group consisting of organic nanotubes, inorganic nanotubes, single-wall nanotubes and multi-walled nanotubes. 
     
     
         4 . The method of  claim 1 , where the metal of the metal complex is selected from zinc and copper (II). 
     
     
         5 . The method of  claim 1 , where the ligating portion is selected from the group consisting of functionalized monopyridines, bispyridines, terpyridines and polypyridine ligands. 
     
     
         6 . The method of  claim 1 , where the ligating component is a monotopic or polytopic ligand capable of coordinating a metal that can coordinate with organic or inorganic nanotubes. 
     
     
         7 . The method of  claim 1 , where at least one of the nanotube and the ligating component is selectively modified with at least one substituent providing at least one physicochemical property, the physiochemical property including solubility, blendablility, and mechanical or electrical properties. 
     
     
         8 . The method of  claim 1 , where the solvent system is polar. 
     
     
         9 . The method of  claim 1 , where the connection between nanotubes has a configuration selected from the group consisting of head-to-head, head-to-wall and wall-to-wall connections. 
     
     
         10 . The method of  claim 1 , where the connection architecture between nanotubes is controlled to give either end to end or branched motifs or combinations thereof. 
     
     
         11 . The method of  claim 1 , where the assembled complex is oligomeric. 
     
     
         12 . A method of reversibly assembling nanocomposites, the method comprising the steps of: reacting first and second oxidized carbon nanotubes with a metal complex in a solvent system to form an assembled complex, wherein the metal complex comprises a metal and a ligating portion selected from monotopic, ditopic and polytopic ligands, with each oxidized carbon nanotube having at least one ligating component coordinating with the metal such that the metal complex serves to connect the first and second nanotubes; and disassembling the assembled complex upon treatment with a competing ligand compound. 
     
     
         13 . A nanocomposite comprising: first and second nanotubes coordinated with a first metal complex to form a network, wherein the metal complex comprises a first metal and a first ligating portion selected from monotopic, ditopic and polytopic pyridine ligands, and wherein each nanotube includes at least one ligating component coordinating with the metal such that the metal complex serves to connect the first and second nanotubes, and wherein the at least one ligating component is modified by at least one substituent that affects network and/or nanotube mechanical, electrical, physical, and chemical properties. 
     
     
         14 . The nanocomposite of  claim 13 , further comprising nanotubes coordinated with a second metal complex comprising a second metal portion and a second ligating portion selected from monotopic, ditopic and polytopic pyridine ligands, to form an assembled complex, where the first metal of the first metal complex is different than the second metal of the second metal complex. 
     
     
         15 . A method of preparing a nanocomposite, the method comprising the steps of: reacting first and second nanotubes with a transition metal pyridine complex in a solvent system to form an assembled complex, wherein the transition metal pyridine complex is comprised of a transition metal and a ligating portion selected from monopyridines, bispyridines, terpyridines and polypyridines coordinated to the metal, and wherein each of the first and second nanotubes includes at least one ligating component coordinating with the transition metal such that the transition metal pyridine complex serves to connect the first and second nanotubes.