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US-12623205-B2 - Superficially porous materials comprising a substantially nonporous hybrid core having narrow particle size distribution

US12623205B2US 12623205 B2US12623205 B2US 12623205B2US-12623205-B2

Abstract

The present invention provides novel chromatographic materials, e.g., for chromatographic separations, processes for its preparation and separations devices containing the chromatographic material; separations devices, chromatographic columns and kits comprising the same; and methods for the preparation thereof. The chromatographic materials of the invention are chromatographic materials comprising having a narrow particle size distribution.

Inventors

  • Kevin D. Wyndham
  • Beatrice Muriithi

Assignees

  • WATERS TECHNOLOGIES CORPORATION

Dates

Publication Date
20260512
Application Date
20220916

Claims (20)

  1. 1 . A superficially porous material comprising superficially porous particles, wherein the superficially porous particles comprise an inorganic/organic hybrid core and one or more layers of a porous shell material surrounding the inorganic/organic hybrid core wherein the inorganic/organic hybrid core has a pore volume of less than 0.10 cc/g; and wherein the inorganic/organic hybrid core has the formula: (A) x (B) y (C) z (IV) wherein the order of repeat units A, B, and C may be random, block, or a combination of random and block; A is an organic repeat unit which is covalently bonded to one or more repeat units A or B via an organic bond; B is an organosiloxane repeat unit which is bonded to one or more repeat units B or C via an inorganic siloxane bond and which may be further bonded to one or more repeat units A or B via an organic bond; C is an inorganic repeat unit which is bonded to one or more repeat units B or C via an inorganic bond; x and y are positive numbers, and z is a non-negative number, wherein x+y+z=1.
  2. 2 . The superficially porous material of claim 1 , wherein the superficially porous material has chromatographically enhancing pore geometry.
  3. 3 . The superficially porous material of claim 1 , wherein the porous shell material is a porous inorganic/organic hybrid material.
  4. 4 . The superficially porous material of claim 1 , wherein the porous shell material is a porous silica.
  5. 5 . The superficially porous material of claim 1 , wherein the porous shell material is a porous composite material.
  6. 6 . The superficially porous material of claim 1 , wherein each layer of the one or more layers of the porous shell material is independently selected from a porous inorganic/organic hybrid material of formula (IV) according to claim 1 , a porous silica, a porous composite material, or mixtures thereof.
  7. 7 . The superficially porous material of claim 1 , wherein the superficially porous material has a spherical core morphology, a rod shaped core morphology, a bent-rod shaped core morphology, a toroid shaped core morphology, or a dumbbell shaped core morphology.
  8. 8 . The superficially porous material of claim 1 , wherein the inorganic/organic hybrid core has a particle size of 0.5-10 μm.
  9. 9 . The superficially porous material of claim 1 , wherein the one or more layers of the porous shell material is independently from 0.05 μm to 5 μm in thickness as measured perpendicular to the surface of the inorganic/organic hybrid core.
  10. 10 . The superficially porous material of claim 1 , wherein the superficially porous material has an average particle size between 0.8-10.0 μm.
  11. 11 . The superficially porous material of claim 1 , wherein the superficially porous material has an average pore diameter of about 25-600 Å.
  12. 12 . The superficially porous material of claim 1 , wherein the superficially porous material has an average pore volume of about 0.11-0.50 cm 3 /g.
  13. 13 . The superficially porous material of claim 1 , wherein pore surface area is between about 10 m 2 /g and 400 m 2 /g.
  14. 14 . The superficially porous material of claim 1 , which has been further surface modified.
  15. 15 . The superficially porous material of claim 1 , which has been further surface modified by: coating with a polymer; coating with a polymer by a combination of organic group and silanol group modification; a combination of organic group modification and coating with a polymer; a combination of silanol group modification and coating with a polymer; formation of an organic covalent bond between an organic group of the material and a modifying reagent; or a combination of organic group modification, silanol group modification and coating with a polymer.
  16. 16 . A separations device having a stationary phase comprising the superficially porous material of claim 1 .
  17. 17 . The superficially porous material of claim 1 , wherein each layer of the one or more layers of the porous shell material is independently selected from a porous inorganic/organic hybrid material of formula (IV) according to claim 1 .
  18. 18 . A chromatographic column, comprising a) a column having a cylindrical interior for accepting a packing material and b) a packed chromatographic bed comprising the superficially porous material of claim 1 .
  19. 19 . A chromatographic device, comprising a) an interior channel for accepting a packing material and b) a packed chromatographic bed comprising the superficially porous material of claim 1 .
  20. 20 . A kit comprising the superficially porous material of claim 1 , and instructions for use.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a divisional of U.S. patent application Ser. No. 16/101,779, filed Aug. 13, 2018, which is a divisional of U.S. patent application Ser. No. 13/638,924, filed Feb. 14, 2013 (issued as U.S. Pat. No. 10,092,893 on Oct. 9, 2018), which is the U.S. National Phase pursuant to 35 U.S.C. § 371, of U.S. international application No. PCT/US2011/045246, filed Jul. 25, 2011, which claims the benefit of U.S. provisional application Ser. No. 61/367,797, filed Jul. 26, 2010. The entire disclosure of each of which is incorporated herein by this reference. BACKGROUND OF THE INVENTION Superficially porous particles (also called pellicular, fused-core, or core-shell particles) were routinely used as chromatographic sorbents in the 1970's. These earlier superficially porous materials had thin porous layers, prepared from the adsorption of silica sols to the surface of ill-defined, polydisperse, nonporous silica cores (>20 μm). The process of spray coating or passing a solution of sols through a bed of particles was commonly used. Kirkland extensively explored the use of superficially porous particles throughout this time and helped develop the Zipax brand of superficially porous materials in the 1970's. A review of Kirkland's career was provided by Unger (Journal of Chromatography A, 1060 (2004) 1). Superficially porous particles have been a very active area of research in the past five years. One prior report that uses a mixed condensation of a tetraalkoxysilane with an organosilane of the type YSi(OR)3 where Y contains an alkyl or aryl group and R is methoxy or ethoxy, has been reported by Unger for both fully porous (EP 84,979 B1, 1996) and superficially porous particles (Advanced Materials 1998, 10, 1036). These particles do not have sufficient size (1-2 μm) for effective use in UPLC, nor do they contain chromatographically enhanced pore geometry. Narrow distribution superficially porous particles have been reported by Kirkland (U.S. Application 20070189944) using a Layer-by-Layer approach (LBL)—however these particles are not highly spherical. Other surfactant-templated approaches, can yield low yields of narrow distribution, fully porous particles, however these approaches have not been used to prepare monodisperse, spherical superficially porous particles having chromatographically enhanced pore geometry. Modern, commercially available superficially porous particles use smaller (<2 μm), monodisperse, spherical, high purity non-porous silica cores. A porous layer is formed, growing these particles to a final diameter between 1.7-2.7 μm. The thickness of the porous layer and pore diameter are optimized to suit a particular application (e.g., small vs. large molecule separations). In order to remove polyelectrolytes, surfactants, or binders (additional reagents added during the synthesis) and to strengthen the particles for use in HPLC or UPLC applications, these material are calcined (500-1000° C. in air). Additional pore enlargement, acid treatment, rehydroxylation, and bonding steps have been reported. Evaluation of superficially porous materials (e.g., Journal of Chromatography A, 1217 (2010) 1604-1615; Journal of Chromatography A, 1217 (2010) 1589-1603) indicates improvements in column performance may be achieved using columns packed with these superficially porous materials. While not limited to theory, improvements were noted in van Deemter terms as well as improved thermal conductivity. The University of Cork also has a recent patent application (WO 2010/061367 A2) on superficially porous particles. Although these reported superficially porous particle processes differ, they can be classified as layering of preformed sols (e.g., AMT process) or growth using high purity tetraalkoxysilane monomers (e.g., the University of Cork process). The AMT and University of Cork processes are similar in that they incorporate a repeated in-process workup (over nine times) using centrifugation followed by redispersion. For the AMT process this is a requirement of the layer-by-layer approach, in which alternate layers of positively charged poly-electrolyte and negatively charged silica sols are applied. For the University of Cork process the in-process workup is used to reduce reseeding and agglomeration events. Particles prepared by this approach have smooth particle surfaces and have notable layer formation by FIB/SEM analysis. While both approaches use similar spherical monodisperse silica cores that increase in particle size as the porous layer increases, they differ in final particle morphology of the superficially porous particle. The AMT process, as shown in FIG. 8, results in bumpy surface features and variation of the porous layer thickness. This difference in surface morphology may be due to variation in the initial layering of sols. Most notably both processes use high temperature thermal treatment in air to remove additives (polyelectrolyte or surfactants) and