Composite powder containing primary nanoparticles of aluminum or aluminum oxide

Abstract

This present invention is directed to a powder comprising a composite of primary nanoparticles of aluminum and/or aluminum oxide, the nanoparticle being separated from the others by an intervening organic or polymeric material, and formed into secondary particles that are substantially larger than the primary nanoparticles.

We claim: 
     
         1 . A powder comprising:
 a composite of primary nanoparticles of at least one of an aluminum and an aluminum oxide, the nanoparticle being separated from each other by at least one of an intervening organic material and a polymeric material, and   the composite being formed into secondary particles that are larger than the primary nanoparticles.   
     
     
         2 . The powder of  claim 1 , where in the organic material includes at least one type of wax. 
     
     
         3 . The powder of  claim 1 , wherein the polymeric material includes at least one of polypropylene, polyethylene terephthalate, polyvinylidene fluoride, polycarbonates, fluoropolymers, polyethylene glycol, polycaprolactone, cellulose acetate butyrate, polyimides, polystyrene, poly (ether ether ketone), polybutadiene, hydroxyl terminated polybutadiene (HTPB), polyphenylene sulphide, acrylonitrile butadiene styrene, polybutadiene acrylonitrile (PBAN), polybutadiene acrylic acid (PBAA), carboxyl terminated polybutadiene (CTPB), polyglycidyl nitrate (PGN), glycidyl azide polymer (GAP), poly(3,3-bis(azidomethyl) Oxetane) Poly(BAMO), poly(3-azidomethyl 3-methyl oxetane) Poly(AMMO), and poly(3-nitratomethyl methyl oxetane) poly(NIMMO) and polysiloxanes. 
     
     
         4 . The powder of  claim 1 , wherein the primary nanoparticles are unagglomerated. 
     
     
         5 . The powder of  claim 1 , wherein the powder is between 0.1 and 98 percent aluminum by mass. 
     
     
         6 . The powder of  claim 1 , wherein the polymeric material is silicone. 
     
     
         7 . The powder of  claim 1 , wherein the secondary particles include additional particles or mixtures of at least one of an oxidizer, explosive, metals other than aluminum, particles of aluminum larger than 50 nm in diameter, and metal-oxides such as iron oxide or copper oxide. 
     
     
         8 . A method of forming a powder comprising:
 a first step of synthesizing a precursor solution containing a solvent and dispersed, unagglomerated primary nanoparticles of at least one of an aluminum and aluminum oxide, and a dissolved binder comprising at least one of an organic and polymeric material, and   a second step of forming a powder by evaporating the solvent.   
     
     
         9 . The method of  claim 8 , wherein the aluminum of the precursor solution is formed by combining an amine adduct of alane with a transition metal catalyst in a solvent. 
     
     
         10 . The method of  claim 9 , wherein the transition metal catalyst is bonded to a polymer. 
     
     
         11 . The method of  claim 8 , wherein at least one constituent of the dissolved binder is a polymer, the polymer including at least one of polypropylene, polyethylene terephthalate, polyvinylidene fluoride, polycarbonates, fluoropolymers, polyethylene glycol, polycaprolactone, cellulose acetate butyrate, polyimides, polystyrene, poly (ether ether ketone), polybutadiene, hydroxyl terminated polybutadiene (HTPB), polyphenylene sulphide, acrylonitrile butadiene styrene, polybutadiene acrylonitrile (PBAN), polybutadiene acrylic acid (PBAA), carboxyl terminated polybutadiene (CTPB), polyglycidyl nitrate (PGN), glycidyl azide polymer (GAP), poly(3,3-bis(azidomethyl) Oxetane) Poly(BAMO), poly(3-azidomethyl 3-methyl oxetane) Poly(AMMO), and poly(3-nitratomethyl methyl oxetane) poly(NIMMO) and polysiloxane. 
     
     
         12 . The method of  claim 8 , wherein at least one constituent of the dissolved binder is a wax. 
     
     
         13 . The method of  claim 8 , wherein the aluminum oxide of the precursor solution is formed by first forming the aluminum and then at least partially oxidizing the aluminum by chemical reaction with an oxidizing agent. 
     
     
         14 . The method of  claim 8 , wherein particles or mixtures of at least one of an oxidizer, explosive, metals other than aluminum, particles of aluminum larger than 50 nm in diameter, and metal-oxides such as iron oxide or copper oxide, are dispersed or dissolved into the precursor solution prior to the forming of a powder by evaporating the solvent. 
     
     
         15 . The method of  claim 8 , wherein the second step is performed by spray drying. 
     
     
         16 . The method of  claim 8 , wherein the second step is performed by electrospraying. 
     
     
         17 . The method of  claim 8 , wherein the second step is performed by freeze drying. 
     
     
         18 . The method of  claim 8 , wherein the second step is performed by evaporating the solvent to form one of a film or bulk solid, followed by mechanically breaking, grinding, or milling the evaporated solvent into a powder