Air-stable metal oxide nanoparticles
Compositions and methods for destroying chemical and biological agents such as toxins and bacteria are provided wherein the substance to be destroyed is contacted with finely divided metal oxide nanoparticles. The metal oxide nanoparticles are coated with a material selected from the group consisting of surfactants, waxes, oils, silyls, synthetic and natural polymers, resins, and mixtures thereof. The coatings are selected for their tendency to exclude water while not excluding the target compound or adsorbates. The desired metal oxide nanoparticles can be pressed into pellets for use when a powder is not feasible. Preferred metal oxides for the methods include MgO, SrO, BaO, CaO, TiO 2 , ZrO 2 , FeO, V 2 O 3 , V 2 O 5 , Mn 2 O 3 , Fe 2 O 3 , NiO, CuO, Al 2 O 3 , SiO 2 , ZnO, Ag 2 O, the corresponding hydroxides of the foregoing, and mixtures thereof.
1. A composition comprising particles of a metal oxide or a metal hydroxide having an average crystallite size of up to about 20 nm and which are at least partially coated with a coating material selected from the group consisting of N,N-dimethyl dodecyl amine, dioctyl sodium sulfosuccinate, 2,4,7,9-tetramethyl-5-decyne-4,7-diol, nonyiphenol polyethylene glycol ethers, C 10-14 alkyl ether phosphates, ethoxylated alcohols, alkyl amines, amine salts, ethoxylated amines, mineral oils, silicone oils, fomblin oils, vegetable oils, carnauba wax, polyethylene wax, silyl reagents, proteins, DNA, KNA, enzymes, carbohydrates, starches, butadiene, styrene, copolymers of butadiene and styrene copolymers of styrene, acrylonitrile, polyvinylchloride, polybutadiene-coacrylonitrile, acrylonitrile-butadiene-styrene, cellulosics, silicon rubbers, nylons, rubbers, polyurethane, rayon, polyvinylidene chloride, polycarbonates, aramids, polyvinylpyrrolidone, polyesters, and mixtures thereof.
2. The composition of claim 1 , said metal oxide or metal hydroxide having a multi-point surface area of at least about 15 m 2 /g.
3. The composition of claim 1 , said particles being selected from the group consisting of oxides and hydroxides of Mg, Sr, Ba, Ca, Ti, Zr, Fe, V, Mn, Fe, Ni, Cu, Al, Si, Zn, Ag, and unalloyed mixtures thereof.
4. A composition comprising particles of a mono-metal oxide or a mono-metal hydroxide having an average crystallite size of up to about 20 nm and which are at least partially coated with a coating material selected from the group consisting of mineral oils, fomblin oils, and silicone oils.
5. A composition comprising particles of a mono-metal oxide or a mono-metal hydroxide having an average crystallite size of up to about 20 nm and which are at least partially coated with a coating material selected from the group consisting of paraffin wax, camauba wax, polyethylene wax, and mixtures thereof.
6. A composition comprising particles of a mono-metal oxide or a mono-metal hydroxide having a multi-point surface area of at least about 15 m 2 /g and an average crystallite size of up to about 20 nm and which are at least partially coated with a coating material selected from the group consisting of mineral oils, fomblin oils, and silicone oils.
7. A composition comprising particles of a mono-metal oxide having the surfaces thereof modified with silyl groups and having an average crystallite size of up to about 20 nm and which are at least partially coated with a coating material selected from the group consisting of surfactants, oils, waxes, polymers, resins, and mixtures thereof.
8. A composition comprising particles of a mono-metal oxide having the surfaces thereof modified with silyl groups and having a multi-point surface area of at least about 15 m 2 /g and an average crystallite size of up to about 20 nm and which are at least partially coated with a coating material selected from the group consisting of surfactants, oils, waxes, polymers, resins, and mixtures thereof.