Metal oxide nanoparticles for smoke clearing and fire suppression
Methods of reducing smoke levels in smoke-affected areas, reducing the level of toxic compounds produced by fires, fire suppression, and increasing flame retardancy. In particular, methods according to the present invention comprise dispersing nanocrystalline particles in the areas affected by smoke for sorption of smoke particulates and toxic compounds produced from a fire. The nanocrystalline particles are also effective for use in methods of fire suppression and flame retardancy.
1. A method of removing toxic materials and smoke particulates formed by a fire from an area comprising contacting a quantity of nanocrystalline particles with a mixture comprising smoke particulates and at least one toxic material formed by a fire for sorbing at least a portion of said at least one toxic material and at least a portion of said smoke particulates, said nanocrystalline particles having an average crystallite size of less than about 25 nm and a surface area of at least about 15 m 2 /g.
2. The method of claim 1 , said nanocrystalline particles selected from the group consisting of metal oxides, metal hydroxides, carbonates, bicarbonates, phosphorus, inorganic phosphorus compounds, boron compounds, antimony compounds, molybdenum compounds, titanium compounds, zirconium compounds, zinc compounds, sulfamates, sulfates, bromine compounds, chlorine compounds, and mixtures thereof.
3. The method of claim 1 , said contacting step comprising dispersing at least about 0.1 g/m 3 of said nanocrystalline particles into at least a portion of said area.
4. The method of claim 1 , said contacting step comprising spraying said nanocrystalline particles into said area from a pressurized container.
5. The method of claim 4 , said nanocrystalline particles being spraying from said pressurized container at a pressure of between about 20-3000 psi.
6. The method of claim 4 , said container being pressurized with a delivery gas.
7. The method of claim 1 , said nanocrystalline particles having an aerodynamic geometric mean diameter (GMD) of between about 1-30 μm.
8. The method of claim 1 , said nanocrystalline particles having a settling velocity of between about 0.001-5 cm/s.
9. The method of claim 1 , said nanocrystalline particles being in the form of powders and/or granules.
10. The method of claim 1 , said at least one other toxic material selected from the group consisting of acrolein, methyl mercaptan, toluene diisocyanate, formaldehyde, isocyanates, HCN, CO, NO, HF, HCl, and mixtures thereof.
11. A method of removing toxic materials formed by a fire from an area comprising contacting a quantity of nanocrystalline particles with at least one toxic material formed by said fire for sorption thereof, said at least one toxic material being selected from the group consisting of acrolein, toluene diisocyanate, formaldehyde, isocyanates, HCN, CO, NO, and mixtures thereof, said nanocrystalline particles having an average crystallites sizes of less than about 25 nm and a surface area of at least about 15 m 2 /g.
12. The method of claim 1 , said smoke particulates comprising carbonaceous smoke particulates.