MICROSPHERES CONTAINING POLYDISPERSED POLYMERIC NANOSPHERES AND POROUS METAL OXIDE MICROSPHERES

Claims

1. A method for producing porous metal oxide microspheres containing a metal oxide, the method comprising formation of a liquid solution or dispersion of monodisperse polymer nanoparticles; forming at least one additional liquid solution or dispersion of monodisperse polymer nanoparticles; mixing each of the solutions or dispersions together; wherein the metal oxide is added to one or more of the solutions or dispersions, and / or wherein the metal oxide is added to the mixture to form a liquid dispersion of the polymer nanoparticles and the metal oxide; formation of liquid droplets of liquid dispersion; drying liquid droplets with the provision of polymer matrix microspheres containing polydisperse polymer nanospheres and a metal oxide; and removal of polymer nanospheres from matrix microspheres to provide porous metal oxide microspheres; where the average diameters of monodisperse polymer nanoparticles of each of the solutions or dispersions are different.

2. The method according to claim 1, comprising forming a liquid dispersion of polymer nanoparticles and a metal oxide, spray drying the liquid dispersion to provide polymer matrix microspheres, and removing the polymer nanospheres from the matrix microspheres.

3. The method according to claim 1, including the formation of liquid droplets using a vibrating nozzle.

4. The method according to claim 1, wherein the liquid droplets are water droplets or oil droplets.

5. The method of claim 1, comprising providing a continuous phase and mixing a liquid dispersion with the continuous phase to form an emulsion containing dispersed liquid droplets of the dispersion, and collecting the droplets.

6. The method according to claim 5, including drying the droplets with the provision of polymer matrix microspheres containing polydisperse polymer nanospheres.

7. The method of claim 6, wherein drying the droplets comprises microwave irradiation, oven drying, vacuum drying, drying in the presence of a desiccant, or a combination thereof.

8. The method according to claim 5, wherein the droplets are formed in a micro-jet device.

9. The method according to any one of claims 1 to 8, wherein the weight / weight ratio of polymer nanoparticles in general to metal oxide is from about 0.5 / 1 to about 10.0 / 1.

10. The method according to any one of claims 1 to 8, wherein the polymer nanoparticles have an average diameter from about 50 nm to about 990 nm.

11. The method according to any one of claims 1 to 8, wherein the polymer is selected from the group consisting of poly(meth)acrylic acid, poly(meth)acrylates, polystyrenes, polyacrylamides, polyethylene, polypropylene, polylactic acid, polyacrylonitrile, their derivatives, their salts, their copolymers and combinations thereof.

12. The method according to any one of claims 1 to 8, wherein the metal oxide is selected from the group consisting of silicon oxide, titanium oxide, aluminum oxide, zirconium oxide, cerium oxide, iron oxides, zinc oxide, indium oxide, tin oxide, chromium oxide, and combinations thereof.

13. The method according to any one of paragraphs 1 to 8, wherein the microspheres are monodisperse.

14. The method according to any one of claims 1 to 8, wherein the porous metal oxide microspheres are a bulk sample of microspheres.

15. The method according to any one of claims 1 to 8, wherein removing the polymer nanospheres from the matrix microspheres comprises calcination, pyrolysis and solvent removal.

16. The method according to any one of claims 1 to 8, wherein removing the polymer nanospheres comprises calcining the matrix microspheres at temperatures from about 350°C to about 700°C for a period of from about 1 hour to about 8 hours.

17. Porous microspheres obtained according to any of paragraphs 1 to 8.

18. A bulk sample of porous microspheres obtained according to any of paragraphs 1-8.