Mesoporous Inorganic Oxide Spheres and Method of Making Same

Abstract

A method of preparing mesoporous inorganic oxide spherical particles includes providing a reaction mixture capable of producing mesoporous inorganic oxide spheres; heating the reaction mixture to produce mesostructured inorganic oxide particles and removing organic material from the mesostructured inorganic oxide particles to form the mesoporous inorganic oxide spherical particles. In one embodiment a reaction mixture includes a proton donor, a source of inorganic oxide, and a source of fluoride. In another embodiment a reaction mixture includes a proton donor, a source of inorganic oxide, and an alcohol. Mesoporous inorganic oxide spheres produced by the method of the present invention are also provided.

1 . A mesoporous inorganic oxide spherical particle produced by a method comprising:
 providing a reaction mixture including:
 a proton donor; 
 a source of inorganic oxide; and 
 a source of fluoride; 
   heating said reaction mixture for not more than 120 minutes to produce mesostructured inorganic oxide particles; and   removing organic material from said mesostructured inorganic oxide particles to form the mesoporous inorganic oxide spherical particles.   
   
   
       2 . A method according to  claim 1 , further comprising:
 mixing said reaction mixture sufficiently prior to said heating step so that said mesostructured inorganic oxide sphere may be formed as a result of said heating step.   
   
   
       3 . A mesoporous inorganic oxide spherical particle according to  claim 2 , wherein said mixing step is performed until said reaction mixture is opaque. 
   
   
       4 . A mesoporous inorganic oxide spherical particle according to  claim 1 , wherein said reaction mixture further includes:
 an alcohol;   a surfactant; and   water.   
   
   
       5 . A mesoporous inorganic oxide spherical particle according to  claim 1 , wherein said proton donor is present in an amount from about 0.3 mol % to about 3.4 mol %. 
   
   
       6 . A mesoporous inorganic oxide spherical particle according to  claim 1 , wherein said proton donor is present in an amount of about 1.5 mol %. 
   
   
       7 . A mesoporous inorganic oxide spherical particle according to  claim 1 , wherein said proton donor comprises hydrochloric acid. 
   
   
       8 . A mesoporous inorganic oxide spherical particle according to  claim 1 , wherein said source of inorganic oxide comprises a compound having a formula Si(OR 1 )(OR 2 )(OR 3 )(OR 4 ) where Si is silicon, O is oxygen, and R 1 , R 2 , R 3 , and R 4  are alkyl chains having 1 to 4 carbon atoms. 
   
   
       9 . A mesoporous inorganic oxide spherical particle according to  claim 1 , wherein said source of inorganic oxide comprises tetraethoxysilane. 
   
   
       10 . A mesoporous inorganic oxide spherical particle according to  claim 1 , wherein said source of inorganic oxide is present in an amount from about 0.017 mol % to about 1.6 mol %. 
   
   
       11 . A mesoporous inorganic oxide spherical particle according to  claim 1 , wherein said source of inorganic oxide is present in an amount of about 0.6 mol %. 
   
   
       12 . A mesoporous inorganic oxide spherical particle according to  claim 1 , wherein said source of fluoride is present in an amount from about 0.019 mol % to about 0.2 mol %. 
   
   
       13 . A mesoporous inorganic oxide spherical particle according to  claim 1 , wherein said source of fluoride is present in an amount of about 0.08 mol %. 
   
   
       14 . A mesoporous inorganic oxide spherical particle according to  claim 1 , wherein said source of fluoride comprises sodium fluoride. 
   
   
       15 . A mesoporous inorganic oxide spherical particle according to  claim 1 , wherein said reaction mixture further comprises an alcohol. 
   
   
       16 . A mesoporous inorganic oxide spherical particle according to  claim 15 , wherein said alcohol is present in an amount from about 1.9 mol % to about 20 mol %. 
   
   
       17 . A mesoporous inorganic oxide spherical particle according to  claim 15 , wherein said alcohol is present in an amount of about 4 mol %. 
   
   
       18 . A mesoporous inorganic oxide spherical particle according to  claim 15 , wherein said alcohol comprises ethanol. 
   
   
       19 . A mesoporous inorganic oxide spherical particle according to  claim 1 , wherein said reaction mixture further comprises a surfactant. 
   
   
       20 . A mesoporous inorganic oxide spherical particle according to  claim 19 , wherein said surfactant is present in an amount from about 0.01 mol % to about the limit of solubility. 
   
   
       21 . A mesoporous inorganic oxide spherical particle according to  claim 19 , wherein said surfactant is present in an amount of about 0.06 mol %. 
   
   
       22 . A mesoporous inorganic oxide spherical particle according to  claim 19 , wherein said surfactant comprises a salt having a trialkylammonium cation and a halide anion. 
   
   
       23 . A mesoporous inorganic oxide spherical particle according to  claim 19 , wherein said surfactant comprises cetyltrimethylammonium bromide. 
   
   
       24 . A mesoporous inorganic oxide spherical particle according to  claim 1 , wherein said heating step is performed at a temperature from about 50° C. to about 230° C. 
   
   
       25 . A mesoporous inorganic oxide spherical particle according to  claim 1 , wherein said heating step is performed at a temperature from about 70° C. to about 100° C. 
   
   
       26 . A mesoporous inorganic oxide spherical particle according to  claim 1 , wherein said heating step is performed for not more than 60 minutes. 
   
   
       27 . A mesoporous inorganic oxide spherical particle according to  claim 1 , wherein said heating step produces mesostructured inorganic oxide spheres that are at least about 90% spherical. 
   
   
       28 . A mesoporous inorganic oxide spherical particle according to  claim 1 , wherein said removing step forms mesoporous inorganic oxide spherical particles having a pore volume of greater than about 0.65 cm 3 /g. 
   
   
       29 . A mesoporous inorganic oxide spherical particle according to  claim 1 , wherein said removing step forms mesoporous inorganic oxide spherical particles having a pore volume of greater than 0.75 cm 3 /g. 
   
   
       30 . A plurality of mesoporous inorganic oxide spherical particles, each comprising one or more pores, wherein the spherical particles have a pore volume of greater than 0.75 cm 3 /g and an average pore diameter of greater than 37 Angstroms. 
   
   
       31 . A plurality of mesoporous inorganic oxide spherical particles according to  claim 30 , wherein said pore volume is greater than about 1 cm 3 /g and said average pore diameter is greater than about 50 Angstroms. 
   
   
       32 . A plurality of mesoporous inorganic oxide spherical particles according to  claim 30 , wherein said pore volume is greater than about 1.3 cm 3 /g.