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

• US 8,778,453 B2
• Filed: 05/29/2007
• Issued: 07/15/2014
• Est. Priority Date: 02/05/1999
• Status: Expired due to Fees

• Current Assignee: Waters Technologies Corporation (Waters Corporation)
• Original Assignee: Waters Technologies Corporation (Waters Corporation)
• Inventors: Jiang, Zhiping, Fisk, Raymond P., O'Gara, John E., Walter, Thomas H., Wyndham, Kevin D.
• Primary Examiner(s): VETERE, ROBERT A
• Application Number:
  US11/807,506
• Publication Number:
  US 20070243383A1
• Time in Patent Office: 2,604 Days
• Field of Search: 427/213.3
• US Class Current: 427/213
• CPC Class Codes: B01D 15/08 Selective adsorption, e.g. chromatography
• CPC Class Codes: B01J 20/103 comprising silica
• CPC Class Codes: B01J 20/22 comprising organic material
• CPC Class Codes: B01J 20/28042 Shaped bodies; Monolithic structures
• CPC Class Codes: B01J 20/28057 Surface area, e.g. B.E.T specific surface area
• CPC Class Codes: B01J 20/28078 Pore diameter
• CPC Class Codes: B01J 20/2808 being less than 2 nm, i.e. micropores or nanopores
• CPC Class Codes: B01J 20/28083 being in the range 2-50 nm, i.e. mesopores
• CPC Class Codes: B01J 20/28095 Shape or type of pores, voids, channels, ducts
• CPC Class Codes: B01J 20/28097 being coated, filled or plugged with specific compounds
• CPC Class Codes: B01J 20/286 Phases chemically bonded to a substrate, e.g. to silica or to polymers
• CPC Class Codes: B01J 20/288 Polar phases
• CPC Class Codes: B01J 20/3204 Inorganic carriers, supports or substrates
• CPC Class Codes: B01J 20/321 consisting of a polymer obtained by reactions involving only carbon to carbon unsaturated bonds
• CPC Class Codes: B01J 20/3212 consisting of a polymer obtained by reactions otherwise than involving only carbon to carbon unsaturated bonds
• CPC Class Codes: B01J 20/3217 Resulting in a chemical bond between the coating or impregnating layer and the carrier, support or substrate, e.g. a covalent bond
• CPC Class Codes: B01J 20/3242 Layers with a functional group, e.g. an affinity material, a ligand, a reactant or a complexing group
• CPC Class Codes: B01J 20/3272 Polymers obtained by reactions otherwise than involving only carbon to carbon unsaturated bonds
• CPC Class Codes: B01J 20/3282 Crosslinked polymers
• CPC Class Codes: B01J 2220/46 Materials comprising a mixture of inorganic and organic materials materials coated or impregnated on a carrier B01J20/32
• CPC Class Codes: B01J 2220/52 : Sorbents specially adapted for preparative chromatography
• CPC Class Codes: B01J 2220/54 : Sorbents specially adapted for analytical or investigative chromatography
• CPC Class Codes: B01J 2220/58 : Use in a single column
• CPC Class Codes: B01J 39/26 : Cation exchangers for chromatographic processes
• CPC Class Codes: B01J 41/20 : Anion exchangers for chromatographic processes
• CPC Class Codes: G01N 2030/525 : surface properties, e.g. porosity
• CPC Class Codes: Y10T 428/249953 : Composite having voids in a component [e.g., porous, cellular, etc.]
• CPC Class Codes: Y10T 428/249978 : Voids specified as micro
• CPC Class Codes: Y10T 428/249979 : Specified thickness of void-containing component [absolute or relative] or numerical cell dimension
• CPC Class Codes: Y10T 428/249981 : Plural void-containing components
• CPC Class Codes: Y10T 428/256 : Heavy metal or aluminum or compound thereof
• CPC Class Codes: Y10T 428/257 : Iron oxide or aluminum oxide
• CPC Class Codes: Y10T 428/259 : Silicic material
• CPC Class Codes: Y10T 428/2982 : Particulate matter [e.g., sphere, flake, etc.]
• CPC Class Codes: Y10T 428/2991 : Coated
• CPC Class Codes: Y10T 428/2993 : Silicic or refractory material containing [e.g., tungsten oxide, glass, cement, etc.]
• CPC Class Codes: Y10T 428/2995 : Silane, siloxane or silicone coating
• CPC Class Codes: Y10T 428/2998 : including synthetic resin or polymer

Abstract

Novel material for chromatographic separations, processes for its preparation, and separations devices containing the chromatographic material. In particular, the disclosure describes porous inorganic/organic hybrid particles having a chromatographically-enhancing pore geometry, which desirably may be surface modified, and that offer more efficient chromatographic separations than that known in the art.

Claims

1. A method of preparation of spherical, porous inorganic/organic hybrid particles having a chromatographically-enhancing pore geometry, comprising the steps of

a) prepolymerizing a mixture of one or more organoalkoxysilanes and a tetraalkoxysilane to produce a polyorganoalkoxysiloxane;

b) preparing an aqueous suspension of said polyorganoalkoxysiloxane, said suspension further comprising a surfactant or combination of surfactants,

c) gelling said aqueous suspension in the presence of a base catalyst so as to produce porous particles; and

d) modifying the pore structure of said porous particles by subjecting said porous particles to hydrothermal treatment

thereby preparing spherical porous inorganic/organic hybrid particles having a chromatographically-enhancing pore geometry in which all pores of a diameter of about <

34 Å

contribute less than about 110 m²/g to the specific surface area of the particle.

2. The method of claim 1 wherein said particles have been surface modified by coating with a polymer.

3. The method of claim 1 wherein said step of modifying the pore structure includes formation of an organic covalent bond between the particle'"'"'s organic group and the modifying reagent.

4. The method of claim 1 wherein said porous particles are prepared by prepolymerizing an organotrialkoxysilane and a tetraalkoxysilane to produce a polyalkyloxysiloxane, and preparing an aqueous suspension of said polyalkyloxysiloxane, and gelling in the presence of a base catalyst so as to produce said porous particles.

5. The method of claim 4 wherein said prepolymerization step comprises hydrolyzing and condensing an mixture of an organotrialkoxysilane and a tetraalkoxysilane in the presence of an acid catalyst to produce said polyalkyloxysiloxane.

6. The method of claim 1 wherein said pore structure of said porous particles is modified by further including a surfactant or combination of different surfactants in said suspension, and by subjecting said porous particles to hydrothermal treatment.

7. The method of claim 6 wherein said surfactant or combination of surfactants are selected from the group consisting of Triton X-45, sodium dodecylsulfate, tris(hydroxymethyl)aminomethane, and any combination thereof.

8. The method of claim 1 wherein said prepolymerization step comprises hydrolyzing and condensing a mixture of one or more organoalkoxysilanes and a tetraalkoxysilane in the presence of an acid catalyst to produce said polyorganoalkoxysiloxane.

9. The method of claim 1 wherein the molar ratio of said organoalkoxysilane and tetraalkoxysilane is from about 0.5:

1 to 0.2;

1.

10. The method of claim 1 wherein said particles have a specific surface area of about 50 to 800 m²/g.

11. The method of claim 1 wherein said particles have a specific surface area of about 100 to 200 m²/g.

12. The method of claim 1 wherein said particles have specific pore volumes of about 0.25 to 1.5 cm³/g.

13. The method of claim 1 wherein said particles have specific pore volumes of about 0.4 to 1.2 cm³/g.

14. The method of claim 1 wherein said particles have an average pore diameter of about 50 to 500 Å

.

15. The method of claim 1 wherein said particles have a micropore surface area of less than about 110 m²/g.

16. The method of claim 1 wherein said particles have an average pore diameter of about 100 to 300 Å

.

17. The method of claim 1, wherein said particles have a specific surface area of about 50 to 800 m²/g, said particles have specific pore volumes of about 0.25 to 1.5 cm³/g, and said particles have an average pore diameter of about 50 to 500 Å

.

18. The method of claim 1 wherein said suspension further comprises a porogen.

19. The method of claim 18 wherein said porogen is toluene.

20. The method of claim 1 wherein said tetraalkoxysilane has the formula Si(OR¹)₄, where R¹ is a C₁-C₃ alkyl moiety.

21. The method of claim 1 wherein said tetraalkoxysilane is selected from the group consisting of tetramethoxysilane and tetraethoxysilane.

22. The method of claim 1 wherein said organoalkoxysilane has the formula R²Si(OR¹)₃ or R⁶[Si(OR¹)₃]_m where R² is a C₁-C₁₈ aliphatic or aromatic moiety, R¹ is a C₁-C₄ alkyl moiety, R⁶ is a C₁-C₁₈ alkylene, alkenylene, alkynylene or arylene moiety bridging two or more silicon atoms, and m is an integer greater than or equal to two.

23. The method of claim 22 wherein R² is methyl, ethyl, phenyl, vinyl, methacryloxypropyl, or styrylethyl and R¹ is ethyl;

or R⁶ is a bridging ethylene group, m=2, and R¹ is ethyl or methyl.

24. The method of claim 1 wherein said organoalkoxysilane has the formula R²Si(OR¹)₃, where R² is a C₁-C₁₈ aliphatic or aromatic moiety and R¹ is a C₁-C₄ alkyl moiety.

25. The method of claim 1 wherein said base catalyst is free of alkali or alkaline earth metal cations.

26. The method of claim 25 wherein said base catalyst is ammonium hydroxide.

27. The method of claim 1 wherein said porous inorganic/organic hybrid particles have the formula SiO₂/(R²_pR⁴_q SiO_t)_n or SiO₂/[R⁶(R²_rSiO_t)_m]_n wherein R² and R⁴ are independently C₁-C₁₈ aliphatic or aromatic moieties, R⁶ is a substituted or unsubstituted C₁-C₁₈ 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.

28. The method of claim 27, wherein n is a number from 0.1 to 1.

29. The method of claim 27 wherein said porous inorganic/organic hybrid particles have average pore diameters of about 100 to 300 Å

.

30. The method of claim 27 wherein n is a number from 0.2 to 0.5.

31. A method of preparation of spherical, porous particles of hybrid silica having a chromatographically-enhancing pore geometry, comprising the steps of

a) prepolymerizing a mixture of one or more organoalkoxysilanes and a tetraalkoxysilane in the presence of an acid catalyst to produce a polyorganoalkoxysiloxane;

b) preparing an aqueous suspension of said polyorganoalkoxysiloxane, said suspension further comprising a surfactant or combination of surfactants, and gelling in the presence of a base catalyst so as to produce porous particles; and

c) modifying the pore structure of said porous particles by hydrothermal treatment,

thereby preparing porous particles of hybrid silica having a chromatographically-enhancing pore geometry in which all pores of a diameter of about <

34 Å

contribute less than about 110 m²/g to the specific surface area of the particle.

32. The method of claim 31 wherein the molar ratio of said organotrialkoxysilane and tetraalkoxysilane is from about 0.5:

1 to 0.2;

1.

33. The method of claim 31 wherein said particles have a specific surface area of about 75 to 600 m²/g.

34. The method of claim 31 wherein said particles have a specific surface area of about 100 to 200 m²/g.

35. The method of claim 31 wherein said particles have a micropore surface area of less than about 110 m²/g.

36. The method of claim 31 wherein said particles have specific pore volumes of about 0.4 to 1.2 cm³/g.

37. The method of claim 31, wherein said particles have a micropore surface area of less than about 105 m²/g.

38. The method of claim 31, wherein said particles have a micropore surface area of less than about 80 m²/g.

39. The method of claim 31, wherein said particles have a micropore surface area of less than about 50 m²/g.

40. The method of claim 31 wherein said particles have an average pore diameter of about 50 to 500 Å

.

41. The method of claim 31 wherein said particles have an average pore diameter of about 100 to 300 Å

.

42. The method of claim 31 wherein said surfactant is an alkylphenoxypolyethoxyethanol.

43. The method of claim 31 wherein said suspension further comprises a porogen.

44. The method of claim 31 wherein said tetraalkoxysilane is selected from the group consisting of tetramethoxysilane and tetraethoxysilane.

45. The method of claim 31, wherein said hybrid silica particles have the formula SiO₂/(R²_pR⁴_qSiO_t)_n or SiO₂/[R⁶ (R²_rSiO_t)_m]_n wherein R² and R⁴ independently C₁-C₁₈ aliphatic or aromatic moieties, R⁶ is a substituted or unsubstituted C₁-C₁₈ 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.

46. The method of claim 45, wherein n is a number from 0.1 to 1.

47. The method of claim 45, wherein said hybrid silica particles have average pore diameters of about 100 to 300 Å

.

48. The method of claim 45 wherein n is a number from 0.2 to 0.5.

49. A method of preparation of spherical, porous inorganic/organic hybrid particles having a chromatographically-enhancing pore geometry, comprising the steps of

a) prepolymerizing a mixture of one or more organoalkoxysilanes and a tetraalkoxysilane to produce a polyorganoalkoxysiloxane;

b) preparing an aqueous suspension of said polyorganoalkoxysiloxane, said suspension further comprising a surfactant or combination of surfactants,

c) gelling said aqueous suspension in the presence of a base catalyst so as to produce porous particles; and

d) modifying the pore structure of said porous particles by subjecting said porous particles to hydrothermal treatment

thereby preparing spherical porous inorganic/organic hybrid particles having a chromatographically-enhancing pore geometry in which;

all pores of a diameter of about <

34 Å

contribute less than about 110 m²/g to the specific surface area of the particle;

said particles have a specific surface area of about 75 to 600 m²/g; and

said particles have an average pore diameter of about 100 to 300 Å

.