Porous polymer media

• US 6,472,443 B1
• Filed: 06/22/2000
• Issued: 10/29/2002
• Est. Priority Date: 06/22/2000
• Status: Expired due to Term

• Current Assignee: National Technology & Engineering Solutions Of Sandia LLC (Honeywell International Inc.)
• Original Assignee: Sandia National Laboratories (Government of the United States of America)
• Inventors: Shepodd, Timothy J.
• Primary Examiner(s): COONEY, JOHN M
• Application Number:
  US09/603,466
• Time in Patent Office: 859 Days
• Field of Search: 521/62, 521/63, 521/64, 521/142, 521/149, 521/150, 521/152, 521/182, 521/183, 521/185, 428/304.4, 428/313.5, 428/317.1
• US Class Current: 521/63
• CPC Class Codes: B01D 15/325 Reversed phase
• CPC Class Codes: B01J 20/26 Synthetic macromolecular compounds
• CPC Class Codes: B01J 20/261 obtained by reactions only involving carbon to carbon unsaturated bonds macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds per se C08F
• CPC Class Codes: B01J 20/267 Cross-linked polymers
• CPC Class Codes: B01J 20/28014 characterised by their form
• CPC Class Codes: B01J 20/28042 Shaped bodies; Monolithic structures
• CPC Class Codes: B01J 20/28059 being less than 100 m2/g
• CPC Class Codes: B01J 20/285 based on polymers
• CPC Class Codes: B01J 2220/54 Sorbents specially adapted for analytical or investigative chromatography
• CPC Class Codes: B01J 2220/82 Shaped bodies, e.g. monoliths, plugs, tubes, continuous beds
• CPC Class Codes: B01J 2220/84 Capillaries
• CPC Class Codes: C08F 2/06 Organic solvent
• CPC Class Codes: G01N 27/44747 Composition of gel or of carrier mixture
• CPC Class Codes: Y10T 428/249953 Composite having voids in a component [e.g., porous, cellular, etc.]
• CPC Class Codes: Y10T 428/249972 Resin or rubber element
• CPC Class Codes: Y10T 428/249982 With component specified as adhesive or bonding agent

Abstract

Highly crosslinked monolithic porous polymer materials for chromatographic applications. By using solvent compositions that provide not only for polymerization of acrylate monomers in such a fashion that a porous polymer network is formed prior to phase separation but also for exchanging the polymerization solvent for a running buffer using electroosmotic flow, the need for high pressure purging is eliminated. The polymer materials have been shown to be an effective capillary electrochromatographic separations medium at lower field strengths than conventional polymer media. Further, because of their highly crosslinked nature these polymer materials are structurally stable in a wide range of organic and aqueous solvents and over a pH range of 2-12.

Claims

1. A method for producing a highly crosslinked porous cast-to-shape polymer structure in capillaries, the method comprising:

preparing a mixture of monomers in a polymerization solvent, wherein the monomers include bifunctional monomers, and wherein the polymerization solvent has a conductivity of at least about 0.4 mho/cm;

filling the capillary tube with the monomer mixture;

polymerizing the monomers; and

exchanging the polymerization solvent for a conducting liquid that can be a buffer solution by applying an electric field to the polymer.

2. The method of claim 1, wherein the polymerization solvent is selected from the group including C₁-C₄ alcohols, C₄ ethers, C₃-C₆ esters, C₁-C₄ carboxylic acids, methyl sulfoxide, sulfolane, N-methyl pyrrolidone, and 35 vol % aqueous buffers and mixtures thereof.

3. The method of claim 2, wherein the polymerizing solvent is a mixture of 60 vol % acetonitrile, 20 vol % ethanol, and 20 vol % 5 mM phosphate buffer pH 6.8.

4. The method of claim 1, wherein the monomers are acrylate monomers.

5. The method of claim 4, wherein the monomers include bifunctional monomers selected from the group including sulfonates, phosphonates, and boronates and ammonium compounds containing active vinyl groups in the molecule.

6. The method of claim 1, wherein the step of polymerizing is by UV radiation.

7. The method of claim 1, wherein the volume ratio of polymerization solvent to monomer is about 67:

33.

8. A porous polymer material made by the method of claim 1.

9. The polymer material of claim 8, wherein the surface area is between about 1-3 m²/g.

10. The method of claim 1, further including the step of pretreating the walls of a capillary.