Composite inorganic particles and methods of making and using the same

Abstract

Composite inorganic particles and compositions containing silica particles are disclosed. Methods of making silica particles and methods of using composite inorganic particles are also disclosed.

What is claimed is: 
     
         1 . A powder of composite inorganic patties comprising:
 particles comprising metal phosphate and metal oxide;   wherein the particles comprise a metal oxide core with metal phosphate formed thereon.   
     
     
         2 . The powder of  claim 1 , wherein the metal phosphate comprises calcium phosphate, magnesium phosphate and mixtures thereof. 
     
     
         3 . The powder of  claim 1 , wherein the metal oxide comprises silica, alumina, titanic, zirconia, and mixtures thereof. 
     
     
         4 . The powder of  claim 1  wherein the metal oxide comprises nano-particles. 
     
     
         5 . The powder of  claim 1 , wherein the composite inorganic particles comprise a weight of metal to weight of metal oxide ratio of about 0.001 to about 0.5. 
     
     
         6 . Composite inorganic particles comprising,
 a metal oxide core with metal phosphate formed thereon;   wherein said particles comprise a particle size distribution such that the median particle size is less than about 50 μm.   
     
     
         7 . The inorganic particles of  claim 6 , wherein the metal phosphate comprises calcium phosphate, magnesium phosphate, and mixtures thereof. 
     
     
         8 . The inorganic particles of  claim 6 , wherein the metal oxide comprises silica, alumina, titanic, zirconia and mixtures thereof. 
     
     
         9 . The inorganic particles of  claim 6 , wherein the particle size distribution such that the median particle size ranges from about 0.001 μm to about 40 μm. 
     
     
         10 . The inorganic particles of  claim 6 , wherein the particle size distribution such that the median particle size ranges from about 0.001 μm to about 30 μm. 
     
     
         11 . The inorganic particles of  claim 6 , wherein the metal oxide comprises nanoparticles. 
     
     
         12 . The inorganic particles of  claim 6 , wherein the composite inorganic particles comprise a weight of metal to weight of metal oxide ratio of about 0.001 to about 0.5. 
     
     
         13 . A method of making composite inorganic particles, said method comprising the steps of:
 (a) providing a dispersion of metal oxide particles:   (b) providing a solution of metal phosphate precursors;   (c) mixing the solution of metal phosphate precursors with the metal oxide particles; and   (d) depositing metal phosphate from the metal phosphate precursors on the metal oxide to form the composite inorganic oxide particles.   
     
     
         14 . The method of making composite inorganic particles of  claim 13 , wherein the metal phosphate comprises calcium phosphate, magnesium phosphate, and mixtures thereof. 
     
     
         15 . The method of making composite inorganic particles of  claim 13 , wherein the metal oxide comprises silica, alumina, titanic, zirconia, and mixtures thereof. 
     
     
         16 . The method of making composite inorganic particles of  claim 13 , wherein the dispersion remains stable for at least six months. 
     
     
         17 . The method of making composite inorganic particles of  claim 13 , wherein the dispersion remains stable for at least twelve months. 
     
     
         18 . The method of making composite inorganic particles of  claim 13 , wherein the metal oxide comprises nano-particles. 
     
     
         19 . The method of making composite inorganic particles of  claim 13 , wherein the composite inorganic particles comprise a weight of metal to weight of metal oxide ratio of about 0.001 to about 0.5. 
     
     
         20 . Composite inorganic particles formed by the method of  claim 13 .