Porous oxide microparticles and composites thereof and methods of making and using same

A method for making a plurality of substantially spherical, oxide-organic polymer composite microparticles, the composite microparticles having a longest linear dimension of 1 micron to 2 millimeters and having a plurality of discrete substantially spherical domains of organic polymer having a longest linear dimension of 30 nanometers to 300 nanometers disposed in an oxide selected from silicon oxide, titanium oxide, zirconium oxide, and combinations thereof and an organic polymer shell comprising the steps of:

• a) contacting an organic polymer precursor, an alkoxy oxide precursor, a chemical initiator, a steric stabilizer, organic solvent, and water to form a reaction mixture comprising a suspension of organic solvent droplets;
• b) holding the reaction mixture for a time and temperature such that microparticles comprising a plurality of substantially spherical organic polymer nanoparticles and organic polymer shell are formed, wherein the alkoxy oxide precursor is in the microparticles and is substantially unreacted;
• c) optionally, contacting the microparticles from b) with additional alkoxy precursor;
• and
• d) contacting the microparticles from b) or c) with an acid catalyst such that the oxide is formed by hydrolysis of the alkoxy oxide precursor resulting in formation of the substantially spherical, oxide-organic polymer composite microparticles.