Heat generating structures

Abstract

A heat generating structure includes a substrate of a first material and a second material coating at least a portion and preferably all of the first material, where the second material is different from the first material. The structure also includes an additional material or compound such as ammonia borane that is impregnated or located within the structure. When the structure is thermally energized, the first and second materials react with each other in an exothermic and self-sustaining reaction that pyrolyzes the impregnated ammonia borane compound to create a target gas, for example, hydrogen from the ammonia borane. An additional material, for example, a thermite, may be interposed between the structure and the ammonia borane to facilitate the ignition of the ammonia borane.

1 . Apparatus, comprising:
 a heat generating structure comprised of a substrate of a first material and a second material coating at least a portion of the first material, where the second material is different from the first material; and   a third material located next to or within the heat generating structure, where the first and second materials, upon being thermally energized, react with each other in an exothermic and self-sustaining reaction that propagates from a first location within the structure along a travel path to a second location within the structure and at a rate that depends upon one or more characteristics of the substrate and the coating, and where the exothermic and self-sustaining reaction of the first and second materials pyrolyzes the third material.   
   
   
       2 . The apparatus of  claim 1 , further comprising a fourth material located between the substrate and the third material, where the fourth material comprises one of a pyrotechnic material or an insulator material. 
   
   
       3 . The apparatus of  claim 2 , where the pyrotechnic material comprises a thermite. 
   
   
       4 . The apparatus of  claim 1 , where at least a portion of the substrate is from the group that comprises a foam and a mesh. 
   
   
       5 . The apparatus of  claim 1 , further comprising a second substrate, where the substrate is located on or within the second substrate. 
   
   
       6 . The apparatus of  claim 1 , where the first and/or second materials are from the group that comprises aluminum, boron, carbon, silicon, zirconium, iron, copper, beryllium, tungsten, hafnium, antimony, magnesium, molybdenum, zinc, tin, nickel, palladium, phosphorus, sulfur, tantalum, manganese, cobalt, chromium, or vanadium. 
   
   
       7 . The apparatus of  claim 1 , where the one or more characteristics of the substrate and the coating include a composition of the first and second materials and a physical configuration of the substrate and the coating, and where the physical configuration of the substrate and the coating includes one or more different directions of the first and second materials at one or more points along the travel path. 
   
   
       8 . The apparatus of  claim 1 , where the first and/or second materials further comprise an energetic binder from the group that comprises glycidyl azide polymer, polyoxetanes, or polyglycidyl nitrate. 
   
   
       9 . The apparatus of  claim 1 , where the first and/or second materials further comprise a binder from the group that comprises hydroxy terminated polybutadiene, hydroxy terminated polyether, carboxy terminated polybutadiene, polyether, polycaprolactone, or polyvinyl chloride. 
   
   
       10 . The apparatus of  claim 1 , where the third material is from the group that comprises nitrates, nitrites, chlorates, perchlorates, oxides, chromates, dichromates, permanganates, iodates, bromates, peroxides or ozonides, where the third material when pyrolyzed by the exothermic and self-sustaining reaction of the first and second materials produces oxygen gas. 
   
   
       11 . The apparatus of  claim 1 , where the third material is from the group that comprises azides, nitrates, nitrites, diazos, triazolones, triazoles or hydrazines, where the third material when pyrolyzed by the exothermic and self-sustaining reaction of the first and second materials produces nitrogen gas. 
   
   
       12 . The apparatus of  claim 1 , where the third material is from the group that comprises carbonates, carbamates, carboxylates or dicarboxylates, where the third material when pyrolyzed by the exothermic and self-sustaining reaction of the first and second materials produces carbon dioxide gas. 
   
   
       13 . The apparatus of  claim 1 , where the third material is from the group that comprises ammonia borane, borohydrides and other metal hydrides, carboranes or hydrazines, where the third material when pyrolyzed by the exothermic and self-sustaining reaction of the first and second materials produces hydrogen gas. 
   
   
       14 . Apparatus, comprising:
 a heat generating structure including a substrate of at least first and second materials formed into a foil structure having at least one layer of the substrate; and   a third material located next to or within the heat generating structure, where the first and second materials, upon being thermally energized, react with each other in an exothermic and self-sustaining reaction that propagates from a first location within the structure along a travel path to a second location within the structure and at a rate that depends upon one or more characteristics of the substrate and the coating, and where the exothermic and self-sustaining reaction of the first and second materials pyrolyzes the third material.   
   
   
       15 . A structure, comprising:
 a substrate comprised of a material arranged in a non-uniform and varying distribution of mass of the substrate material along a length of the substrate in a propagation direction; and   a second material located next to or within the substrate material, where the substrate material, upon being thermally energized, reacts in an exothermic and self-sustaining reaction that propagates from a first location within the substrate along a travel path to a second location within the substrate at a rate that depends upon one or more characteristics of the substrate, where a physical configuration of the substrate includes one or more different directions of the substrate material at one or more points along the travel path, and where the exothermic and self-sustaining reaction of the substrate material pyrolyzes the second material.   
   
   
       16 . The structure of  claim 15 , where the substrate material further comprises an energetic binder from the group that comprises glycidyl azide polymer, polyoxetanes, or polyglycidyl nitrate, and where the substrate material is formed around a wire. 
   
   
       17 . The structure of  claim 15 , where the substrate material comprises a fluoropolymer from the group that comprises polytetrafluoroethylene, fluoroelastomers, fluorosurfactants, or fluoroadditives, and where the fluoropolymer substrate material contains a plurality of metal particles dispersed therein, where the metal particles are from the group that comprises aluminum, magnesium, boron, beryllium, zirconium, titanium or zinc, and where the substrate material containing the metal particles dispersed therein is extruded to form a filament. 
   
   
       18 . The structure of  claim 15 , where the substrate material further comprises a binder from the group that comprises hydroxy terminated polybutadiene, hydroxy terminated polyether, carboxy terminated polybutadiene, polyether, polycaprolactone, or polyvinyl chloride. 
   
   
       19 . The structure of  claim 17 , where the substrate material further comprises a binder from the group that comprises hydroxy terminated polybutadiene, hydroxy terminated polyether, carboxy terminated polybutadiene, polyether, polycaprolactone, and polyvinyl chloride. 
   
   
       20 . The structure of  claim 15 , where the substrate material comprises a powdered mixture of a fuel material and an oxidizer material, and where the substrate material further comprises an energetic binder from the group that comprises glycidyl azide polymer, polyoxetanes, or polyglycidyl nitrate, and where the substrate material is formed around a wire. 
   
   
       21 . The structure of  claim 15 , where the substrate material comprises a powdered mixture of a fuel material and an oxidizer material, and where the substrate material further comprises a binder from the group that comprises hydroxy terminated polybutadiene, hydroxy terminated polyether, carboxy terminated polybutadiene, polyether, polycaprolactone, or polyvinyl chloride, and where the substrate material is formed around a wire. 
   
   
       22 . The structure of  claim 15 , where the substrate comprises a plurality of tubes, where each tube contains the substrate material. 
   
   
       23 . The structure of  claim 22 , where the substrate material further comprises an energetic binder from the group that comprises glycidyl azide polymer, polyoxetanes, or polyglycidyl nitrate. 
   
   
       24 . The structure of  claim 22  where the substrate material comprises a fluoropolymer from the group that comprises polytetrafluoroethylene, fluoroelastomers, fluorosurfactants, or fluoroadditives, and where the fluoropolymer substrate material contains a plurality of metal particles dispersed therein, where the metal particles are from the group that comprises aluminum, magnesium, boron, beryllium, zirconium, titanium or zinc. 
   
   
       25 . The structure of  claim 22 , where the substrate material further comprises a binder from the group that comprises hydroxy terminated polybutadiene, hydroxy terminated polyether, carboxy terminated polybutadiene, polyether, polycaprolactone, or polyvinyl chloride.