Reversible polymer/metal nano-composites and method for manufacturing same

Abstract

The present invention provides a polymer/metal nano-composite. The nano-composite includes at least one copolymer chain having alkenyl monomer units and maleimide monomer units, and a nano-sized metal or inorganic crystal. It also provides a method of producing nano-sized metal/inorganic crystals in pure form. These nano-composites and nano-crystals can be useful as polymer fillers, tire rubber compounds, semiconductors, nano-magnets, catalysts, and quantum dots etc.

1 . A polymer nano-sized particle comprised of at least one copolymer having alkenyl monomer units and maleimide monomer units, said nanoparticle having a core comprised substantially of said alkenyl monomer and a shell comprised substantially of said maleimide monomer, and said nanoparticle having a mean average diameter of less than about 100 nm.  
     
     
         2 . The composition of  claim 1  wherein the alkenyl monomer units are selected from the group consisting of vinyl-substituted aromatic hydrocarbons, R 1 R 2 ethylenes, alkyl vinyl ethers, and mixtures thereof.  
     
     
         3 . The composition of  claim 2  wherein said vinyl-substituted aromatic hydrocarbons are chosen from the group consisting of styrene, α-methylstyrene, 1-vinylnaphthalene, 2-vinyl-naphthalene, 1-α-methylvinylnaphthalene, 2-α-methylvinylnaphthalene, as well as alkyl, cycloalkyl, aryl, alkaryl, and aralkyl derivatives thereof, in which the total number of carbon atoms in the combined hydrocarbon is not greater than about 18, as well as any di- or tri-vinyl-substituted aromatic hydrocarbons, and mixtures thereof.  
     
     
         4 . The composition of  claim 2  wherein said R 1 R 2 ethylene is selected from the group consisting of ethylene, propylene, butylene, isobutylene, pentene, hexene, and heptene.  
     
     
         5 . The composition of  claim 2  wherein said alkyl vinyl ether is selected from the group consisting of methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, pentyl vinyl ether, hexyl vinyl ether, alkyl vinyl ethers with up to 12 carbon atoms in the alkyl substituent, and mixtures thereof.  
     
     
         6 . The composition of  claim 1  wherein said nanoparticle includes between about 10 and 500 polymer chains.  
     
     
         7 . The composition of  claim 1  wherein said nanoparticle present in a non-polar solvent.  
     
     
         8 . The composition of  claim 1  wherein said nanoparticle capable of swelling in the presence of a polar solvent.  
     
     
         9 . The composition of  claim 1  wherein said nanoparticle further includes a complexed metal.  
     
     
         10 . A polymer metal composite nanoparticle comprised of alkenyl monomer units and maleimide monomer units, said nanoparticles having a mean average diameter of less than about 100 nm and further including metal molecules complexed to said maleimide monomer.  
     
     
         11 . The composite nanoparticle of  claim 10  wherein said metal is selected from Cu, Ti, Fe, Cd and mixtures thereof.  
     
     
         12 . A method for forming a polymer nanoparticle comprising: 
 a. forming copolymer chains comprised of alkenyl monomer units and maleimide monomer units in a dry state; and    b. combining said copolymer chains with a non-polar solvent,    whereby the copolymer chains form micelles.    
     
     
         13 . The method of  claim 12  wherein said alkenyl monomer units are selected from the group consisting of vinyl-substituted aromatic hydrocarbons, R 1 R 2 ethylene, alkyl vinyl ether, and mixtures thereof.  
     
     
         14 . The method of  claim 13  wherein said vinyl-substituted aromatic hydrocarbons are chosen from the group consisting of styrene, α-methylstyrene, 1-vinylnaphthalene, 2-vinyl-naphthalene, 1-α-methylvinylnaphthalene, 2-α-methylvinylnaphthalene, as well as alkyl, cycloalkyl, aryl, alkaryl, and aralkyl derivatives thereof, in which the total number of carbon atoms in the combined hydrocarbon is not greater than about 18, as well as any di- or tri-vinyl-substituted aromatic hydrocarbons, and mixtures thereof.  
     
     
         15 . The method of  claim 13  wherein said R 1 R 2 ethylene is selected from the group consisting of ethylene, propylene, butylene, isobutylene, pentene, hexene, heptene, and mixtures thereof.  
     
     
         16 . The method of  claim 13  wherein said alkyl vinyl ether is selected from the group consisting of methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, pentyl vinyl ether, hexyl vinyl ether, alkyl vinyl ethers with up to about 12 carbon atoms in the alkyl substituent, and mixtures thereof.  
     
     
         17 . The method of  claim 12  wherein said maleimide comprises the reaction product of maleic anhydride and ammonia.  
     
     
         18 . The method of  claim 12  wherein said maleimide comprises the reaction product of maleic anhydride and a primary amine.  
     
     
         19 . A method for forming metal nanocomposites comprising: 
 a. forming copolymer chains comprised of alkenyl monomer units and maleimide monomer units in a dry state;    b. combining said copolymer chains with a non-polar solvent whereby the copolymer chains form micelles; and    c. adding at least one metal in solution to the solvent containing said micelles whereby the metal complexes with the copolymer chains forming said metal nanocomposites.    
     
     
         20 . The method of  claim 19  further comprising separating the metal nanocomposites from the nanoparticles by effecting a solvent change.  
     
     
         21 . The method of  claim 20  wherein said solvent change includes a polar solvent.  
     
     
         22 . The method of  claim 19  wherein said metal is selected from the group consisting of Cu, Ti, Fe, Cd, Ni, Pd, and mixtures thereof.  
     
     
         23 . The method of  claim 19  wherein said metal nanocomposites have a mean average diameter less than about 100 nm.  
     
     
         24 . A nano-sized metal/inorganic crystal, which has a mean average diameter less than about 100 nm.  
     
     
         25 . A method for forming the nano-sized metal/inorganic crystal of  claim 24  comprising: 
 a. forming copolymer chains comprised of alkenyl monomer units and maleimide monomer units in a dry state;    b. combining said copolymer chains with a non-polar solvent, whereby the copolymer chains form micelles;    c. adding at least one metal in solution to the solvent containing said micelles, whereby the metal complexes with the copolymer chains forming said metal nanocomposites;    d. optionally transforming the metal into an inorganic salt; and    e. forming the nano-sized metal/inorganic crystal by removing the copolymer.    
     
     
         26 . The method of  claim 25 , wherein the metal is selected from Cu, Ti, Fe, Cd, Ni, or Pd; the inorganic salt in step (f) is sulfide or carbonate; and the removing of the copolymer in step (g) is achieved by solvent change which will dissolve the copolymer but will not dissolve the metal/inorganic salt.  
     
     
         27 . The method of  claim 26 , in wherein the metal comprises Cu, the inorganic salt in step (f) comprises, and the solvent in step (g) comprises THF.  
     
     
         28 . A tire rubber, comprising the polymer nano-sized particle of  claim 1 .  
     
     
         29 . A tire rubber, comprising the polymer metal composite nano-particle of  claim 10 .  
     
     
         30 . A tire rubber, comprising the nano-sized metal/inorganic crystal of  claim 24.