Monday, February 22, 2010

NanoScale Corporation Metal Oxide Nanoparticles for Smoke Clearing and Fire Suppression also Absorb Toxic Materials Produced by Fire

NanoScale Corporation  (Manhattan, KS) received U.S. Patent7,661,483 for its metal oxide nanoparticles used in smoke clearing and fire suppression.   The application method consists of dispersing nanocrystalline particles in the areas affected by smoke for sorption of smoke particulates and toxic compounds produced from a fire.  The application step consists of spraying the nanocrystalline particles onto a fire from a pressurized container. The nanocrystalline particles are also effective in flame retardancy and flame retardant composites.The metal oxide nanoparticles are sold under the trade name NanoActive®.

The nanocrystalline particles have a settling velocity of between about 0.001-5 cm/s.  Nanocrystalline particles are selected from the group consisting of the metal oxides and hydroxides of Sb, Mo, Ti, Zr, Zn, and mixtures of them.  The nanocrystalline particles are combined with an inorganic chemical such as ammonium phosphate, ammonium sulfate, calcium carbonate, magnesium aluminosilicate, and monoammonium phosphate.  NanoActive ®materials include MgO plus, MgO, TiO2-12, TiO2-07, and MgO Plus granules.

The relatively high surface area nanocrystalline particles are able to reduce the levels of various compounds and materials produced by fires as well as suppress the fire itself, say inventors Ravichandra S. Mulukutla, Paul S. Malchesky, Ronaldo Maghirang, John S. Klabunde, Kenneth J. Klabunde and Olga Koper.

The nanocrystalline particles preferably have crystallites sizes of less than about 25 nm, and most preferably between about 2-10 nm. The nanocrystalline particles preferably exhibit a Brunauer-Emmett-Teller (BET) multipoint surface area of at least about 15 m2/g, more preferably at least about 70 m2/g, and most preferably from about 200-850 m2/g. 

 Smoke produced by a fire may contain, in addition to carbonaceous smoke particulates, various toxic compounds such as acrolein, toluene diisocyanate, formaldehyde, isocyanates, HCN, CO, NO, HF, and HCl. The metal oxide nanoparticles are able to clear smoke in order to improve the visibility of an area and also to reduce the level of toxic compounds present in the area.

NanoScale nanocrystalline particles are also useful for suppressing the fire, including any smoldering embers or other material, which produce smoke and toxic compounds. These metal oxide nanoparticles are applicable to open-air environments as well as closed environments (i.e., closed rooms, chambers, aircraft cabins, etc.). 

The hazards to human and animal life and health associated with fires, smoke, and toxic materials produced by fires are well known. Inhalation of toxic gases in smoke is the primary cause of fatalities in most fires. Fire is a complex, dynamic, physiochemical phenomenon and is a result of a rapid chemical reaction generating smoke, heat, flame and light.

Each fire exhibits individual characteristics which depend on the types of burning materials and environmental conditions. Smoke is a complex of particular matter, as well as a variety of invisible combustion gases and vapors suspended in the fire atmosphere. Fire, smoke and the toxic compounds associated therewith can also cause poor visibility conditions thereby hampering the conduct of military and civilian ground operations (i.e., battlefield operations, search and rescue operations, aircraft operations, etc.).

Within the fire community it has long been an accepted fact that the health hazard from fire smoke is due mainly to its content of CO. Lately, this scenario has also come to include hydrogen cyanide (HCN). Isocyanates have also become the subject of focus as they are used for manufacturing polyurethanes and frequently used for manufacturing glues and lacquers. Isocyanates are known to induce asthma in people exposed to even relatively small amount.

In addition, smoke and toxic chemicals can be produced by a number of industrial processes. Newer environmental standards require reduction of the amounts of these materials from industrial flue gases prior to release into the atmosphere.

Conventional dry chemical systems for fire suppression have involved the use of pressurized containers including various dry compounds such as ammonium phosphate, ammonium sulfate, calcium carbonate, magnesium aluminosilicate, mono ammonium phosphate, sodium bicarbonate, potassium bicarbonate, and muscovite mica. However, these systems at best are only marginally effective at smoke removal and do not address the hazards presented by fire-produced toxic compounds.

Therefore, say the inventors,  there is a real an unfulfilled need in the art for methods of smoke-clearing, fire suppression, flame retardancy and sorption of toxic chemicals produced by fires and industrial processes. 

NanoActive® metal oxides overcome the above problems by providing methods for fire suppression, smoke clearing, flame retardancy and removal of toxic materials formed by fires. In one aspect, the materials provide a method of enhancing visibility in a smoke-affected area comprising, consisting of, or consisting essentially of the step of dispersing a quantity of nanocrystalline particles to the smoke-affected area for sorbing at least a portion of the smoke.

In another aspect, the present method of removing toxic materials formed by a fire consists essentially of dispersing a quantity of nanocrystalline particles in the area for sorbing at least one toxic material formed by the fire.

Flame retardant composites can be made by incorporating into the article a quantity of flame retardant nanocrystalline particles. 

NanoScale has developed a proprietary line of safe metal oxides powders called NanoActive®. NanoScale proprietary synthesis methods were developed with a goal of enhancing adsorption kinetics, increasing chemical reactivity, and maintaining the earth mineral safety in  nanocrystalline forms for the destruction of toxic materials, including air and water pollutants, hazardous chemicals, biological organisms, and chemical warfare agents.

NanoScale manufacturing techniques produce advanced materials with small crystallite sizes (eg., 2-10 nm), which agglomerate into micron size particles (2-10 μm) and have very high porosity (up to 1.5 cc/g). This porosity allows for the entire particle to be utilized in the reaction. Specifically, the molecular structure allows for higher chemical reaction and faster binding affinity to reactive agents on surfaces or airborne. This highly porous structure enables the materials to absorb substances into the pore space by contact with coordinated unsaturated atoms/ions on the corners and edges of the crystal lattice structure.
1310 Research Park Drive
Manhattan, KS 66502
(785) 539-0179

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