Appeal No. 94-2414
Application 07/911,504
quantity of water containing fluoride ion to form a reactant
mixture and to hydrolyze the silicon tetrachloride to silica;
(b) permitting the silica to gel;
(c) aging the gel for about 4 hours;
(d) separately recovering the silica gel from the remainder
of the reactant mixture;
(e) washing said silica gel until the pH of the gel is at
least above about 3;
(f) drying said washed gel to obtain dry gel having
essentially one form of silanol moiety; and
(g) reacting said dried gel with a quantity of
organochlorosilane to bond the organochlorosilane to said dry
gel.
34. Silica gel produced by the method of claim 33.
35. A porous silica gel having a specific surface area
between about 200 and 600 m /g, average pore diameters in the2
range of about 50 to about 200 Angstroms and a narrow pore
diameter distribution wherein said distribution has a standard
deviation in pore diameter less than about 25 percent of the
average pore diameter,
wherein said silica gel is produced by the method
comprising:
(a) mixing a solution of silicon tetrafluoride and a water-
soluble, non-aqueous solvent with at least a stoichiometric
quantity of water to form a reactant mixture and to hydrolyze the
silicon tetrafluoride to silica;
(b) permitting the silica to gel;
(c) separately recovering the silica gel from the remainder
of the reactant mixture and;
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Last modified: November 3, 2007