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US 6,528,167 B2Granted
Porous hybrid particles with organic groups removed from the surface
AssigneeWaters Investments Limited
InventorJohn E. O'Gara
Life of this patent
Estimating the term…
Abstract
A material for chromatographic separations, processes for its preparation, and separation devices containing the chromatographic material. In particular, porous inorganic/organic hybrid materials are provided with a decreased concentration of surface organic groups. These particles may be surface modified and have enhanced stability at low pH.
Claims43
A hybrid particle for chromatographic separations, said particle having an interior area and an exterior surface, said particle having a composition represented by:
- [A]y[B]x (Formula I),
- wherein x and y are whole number integers and A is
- SiO2/(R1pR2qSiOt)n (Formula II)
- and/or
- SiO2/[R3(R1rSiOt)m]n (Formula III);
- wherein R1 and R2 are independently a substituted or unsubstituted C1 to C7 alkyl group, or a substituted or unsubstituted aryl group, R3 is a substituted or unsubstituted C1 to C7 alkylene, alkenylene, alkynylene, or arylene group bridging two or more silicon atoms, p and q are 0, 1, or 2, provided that p+q=1 or 2, and that when p+q=1, t=1.5, and when p+q=2, t=1;
- r is 0 or 1, provided that when r=0, t=1.5, and when r=1, t=1;
- m is an integer greater than or equal to 2;
- and n is a number from 0.01 to 100;
- B is:
- SiO2/(R4vSiOt)n (Formula IV)
- wherein R4 is hydroxyl, fluorine, alkoxy, aryloxy, substituted siloxane, protein, peptide, carbohydrate, nucleic acid, or combinations thereof, R4 is not R1, R2, or R3;
- v is 1 or 2, provided that when v=1, t=1.5, and when v=2, t=1;
- and n is a number from 0.01 to 100;
- said interior of said particle having a composition of A;
- said exterior surface of said particle having a composition represented by A and B, and wherein said exterior composition is between about 1 and about 99% of the composition of B and the remainder comprising A.
13 more elements
A method of preparing hybrid chromatographic particles, comprising:
- a) prepolymerizing a mixture of an organoalkoxysilane and a tetraalkoxysilane in the presence of an acid catalyst to produce a polyalkoxysiloxane.
- b) preparing an aqueous suspension of said polyalkoxysiloxane, said suspension further comprising a surfactant, and gelling in the presence of a base catalyst so as to produce porous particles having silicon C1 to C7 alkyl groups, substituted or unsubstituted aryl groups, substituted or unsubstituted C1 to C7 alkylene, alkenylene, alkynylene, or arylene groups.
- c) modifying the pore structure of said porous particles by hydrothermal treatment;
- and
- d) replacing one or more surface C1 to C7 alkyl groups, substituted or unsubstituted aryl groups, substituted or unsubstituted C1 to C7 alkylene, alkenylene, alkynylene, or arylene groups of the particle with hydroxyl, fluorine, alkoxy, aryloxy, or substituted siloxane groups.
2 more elements
Dependencies are inferred from the claim text.