Porous inorganic/organic hybrid particles for chromatographic separations and process for their preparation

1. A porous material comprising an organosiloxane/SiO 2 material having the formula SiO 2 /(R 2 p R 4 q SiO t ) n or SiO 2 /[R 6 (R 2 r SiO t ) m ] n wherein R 2 and R 4 are independently C 1 -C 18 aliphatic, styryl, vinyl, propanol, or aromatic moieties, R 6 is a substituted or unsubstituted C 1 -C 18 alkylene, alkenylene, alkynylene or arylene moiety 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 0.03 to 1 and wherein all pores of the porous material having a diameter of about <34 Å contribute less than about 110 m 2 /g to the specific surface area of the porous material.

2. The porous material of claim 1 , having the formula SiO 2 /(R 2 p R 4 q SiO t ) n wherein p is 1 and q is 0.

3. The porous material of claim 1 , wherein n is 0.2 to 0.5.

4. The porous material of claim 1 , having the formula SiO 2 /(R 2 p R 4 q SiO t ) n wherein R 2 and R 4 are independently lower alkyl.

5. The porous material of claim 4 , wherein R 2 is ethyl.

6. The porous material of claim 1 , having the formula SiO 2 /[R 6 (R 2 r SiO t ) m ] n .

7. The porous material of claim 6 , wherein R 6 is ethylene.

8. The porous material of claim 6 wherein r is 0 and t is 1.5.

9. The porous material of claim 6 wherein m is 2.

10. The porous material of claim 1 , having a micropore surface area less than about 110 m 2 /g.

11. The porous material of claim 10 , having a micropore surface area less than about 80 m 2 /g.

12. The porous material of claim 1 , having a specific surface area of about 50 m 2 /g to about 800 m 2 /g.

13. The porous material of claim 12 , having a specific surface area of about 100 m 2 /g to about 353 m 2 /g.

14. The porous material of claim 13 , having a specific surface area of about 100 m 2 /g to about 267 m 2 /g.

15. The porous material of claim 1 , having an average pore diameter of about 50 Å to about 500 Å.

16. The porous material of claim 15 , having an average pore diameter of about 100 Å to about 300 Å.

17. The porous material of claim 15 , having an average pore diameter of about 79 Å to about 238 Å.

18. The porous material of claim 1 , having a specific pore volume of about 0.25 to 1.5 cm 3 /g.

19. The porous material of claim 18 , having a specific pore volume of about 0.76 to 1.0 cm 3 /g.

20. The porous material of claim 18 , having a specific pore volume of about 0.40 to 0.76 cm 3 /g.

21. The porous material of claim 1 , wherein said material is surface modified by a surface modifier selected from the group consisting of an organic group surface modifier, a silanol group surface modifier, a polymeric coating surface modifier, and combinations thereof.

22. The porous material of claim 21 , wherein said material is surface modified with a surface modifier having the formula Z a (R′) b Si—R, where Z=Cl, Br, I, C 1 -C 5 alkoxy, dialkylamino or trifluoromethanesulfonate; a and b are each an integer from 0 to 3 provided that a+b=3; R′ is a C 1 -C 6 straight, cyclic or branched alkyl group, and R is a functionalizing group.

23. The porous material of claim 21 , wherein the functionalizing group R is selected from the group consisting of alkenyl, alkynyl, ester, and alkyl or aryl group containing an embedded polar functionality.

24. The porous material of claim 21 , wherein said functionalizing group R is a C 1 -C 30 alkyl group.

25. The porous material of claim 21 , wherein said surface modifier is selected from the group consisting of octyltrichlorosilane and octadecyltrichlorosilane.

26. The porous material of claim 21 , wherein said surface modifier is a combination of an organic group surface modifier and a silanol group surface modifier.

27. The porous material of claim 21 , wherein said surface modifier is a combination of an organic group surface modifier and a polymeric coating surface modifier.

28. The porous material of claim 21 , wherein said surface modifier is a combination of a silanol group surface modifier and a polymeric coating surface modifier.

29. The porous material of claim 21 , wherein said surface is modified via formation of an organic covalent bond between an organic group of the material and a surface modifier.

30. The porous material of claim 21 , wherein said surface modifier is a combination of an organic group surface modifier, a silanol group surface modifier, and a polymeric coating surface modifier.

31. The porous material of claim 21 , wherein said surface modifier is a silanol group surface modifier.

32. A particle comprising an organosiloxane/SiO 2 material having the formula SiO 2 /(R 2 p R 4 q SiO t ) n or SiO 2 /[R 6 (R 2 r SiO t ) m ] n wherein R 2 and R 4 are independently C 1 -C 18 aliphatic, styryl, vinyl, propanol, or aromatic moieties, R 6 is a substituted or unsubstituted C 1 -C 18 alkylene, alkenylene, alkynylene or arylene moiety 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 0.03 to 1; wherein all pores of the particle having a diameter of about <34 Å contribute less than about 110 m 2 /g to the specific surface area of the particle.

33. The particle of claim 32 , wherein the particle has a low micropore surface area.

34. A separations device having a stationary phase comprising a porous material comprising an organosiloxane/SiO 2 material having the formula SiO 2 /(R 2 p R 4 q SiO t ) n or SiO 2 /[R 6 (R 2 r SiO t ) m ] n wherein R 2 and R 4 are independently C 1 -C 18 aliphatic, styryl, vinyl, propanol, or aromatic moieties, R 6 is a substituted or unsubstituted C 1 -C 18 alkylene, alkenylene, alkynylene or arylene moiety 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 0.03 to 1 and wherein all pores of the porous material having a diameter of about <34 Å contribute less than about 110 m 2 /g to the specific surface area of the porous material.

35. A chromatographic column, comprising

a. a column having a cylindrical interior for accepting a packing material, and

b. a packed chromatographic bed comprising a porous material comprising an organosiloxane/SiO 2 material having the formula SiO 2 /(R 2 p R 4 q SiO t ) n or SiO 2 /[R 6 (R 2 r SiO t ) m ] n wherein R 2 and R 4 are independently C 1 -C 18 aliphatic, styryl, vinyl, propanol, or aromatic moieties, R 6 is a substituted or unsubstituted C 1 -C 18 alkylene, alkenylene, alkynylene or arylene moiety 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 0.03 to 1 and wherein all pores of the porous material having a diameter of about <34 Å contribute less than about 110 m 2 /g to the specific surface area of the porous material.

36. The chromatographic column of claim 35 , wherein said material has been surface modified.

37. The chromatographic column of claim 36 , wherein said material has been surface modified by a surface modifier selected from the group consisting of an organic group surface modifier, a silanol group surface modifier, a polymeric coating surface modifier, and combinations thereof.

38. The chromatographic column of claim 35 , wherein said surface modifier has the formula Z a (R′) b Si—R, where Z=Cl, Br, I, C 1 -C 5 alkoxy, dialkylamino or trifluoromethanesulfonate; a and b are each an integer from 0 to 3 provided that a+b=3; R′ is a C 1 -C 6 straight, cyclic or branched alkyl group, and R is a functionalizing group.