SURFACTANTS AND POLYMERIZABLE SURFACTANTS BASED ON ROOM-TEMPERATURE IONIC LIQUIDS THAT FORM LYOTROPIC LIQUID CRYSTAL PHASES WITH WATER AND ROOM-TEMPERATURE IONIC LIQUIDS

• US 20080029735A1
• Filed: 07/03/2007
• Published: 02/07/2008
• Est. Priority Date: 07/03/2006
• Status: Active Grant

• Current Assignee: The Board of Regents of the University of Colorado (University of Colorado System)
• Original Assignee: The Board of Regents of the University of Colorado (University of Colorado System)
• Inventors: Gin, Douglas, Bara, Jason, Noble, Richard, Zeng, Xiaohui
• Granted Patent: US 7,931,824 B2
• Time in Patent Office: Days
• US Class Current: 252/299.61
• CPC Class Codes: B01D 2323/30 Cross-linking
• CPC Class Codes: B01D 69/10 Supported membranes; Membrane supports
• CPC Class Codes: B01D 71/06 Organic material
• CPC Class Codes: C07D 233/64 with substituted hydrocarbon radicals attached to ring carbon atoms, e.g. histidine
• CPC Class Codes: C09K 19/348 containing at least two nitrogen atoms
• CPC Class Codes: C09K 19/38 Polymers
• CPC Class Codes: C09K 19/54 Additives having no specific mesophase characterised by their chemical composition
• CPC Class Codes: C09K 2019/0448 the end chain group being a polymerizable end group, e.g. -Sp-P or acrylate
• CPC Class Codes: C09K 2019/528 Surfactants
• CPC Class Codes: C11D 17/0026 Structured liquid compositions, e.g. liquid crystalline phases or network containing non-Newtonian phase

Abstract

A modular surfactant architecture based on room temperature ionic liquids (RTILs) has been developed that affords non-polymerizable and polymerizable amphiphiles that form lamellar (L), hexagonal (H) or bicontinuous cubic (Q) LLC phases when mixed with water or RTILs serving as the polar solvent. The amphiphiles are imidazolium salts having two or more imidazolium head groups joined by one or more spacers. Polymerization of the LLC assembly can produce polymeric materials having ordered nanopores, with the ordering of the pores determined by the LLC phase.

Claims

1. A polymerizable surfactant composition having the general formula:

2. The surfactant composition of claim 1, wherein L is —

(CH₂)_n, n is 1 to 10.

3. The surfactant composition of claim 1, wherein L is —

(CH₂CH₂—

(O—

CH₂—

CH₂)_p—

, p is 1 to 3.

4. The surfactant composition of claim 1, wherein the polymerizable group P is an acrylate, methacrylate or diene group.

5. The surfactant composition of claim 4, wherein the polymerizable group P is an acrylate group.

13. A cross-linked lyotropic liquid crystal polymer comprising cross-linked surfactants according to claim 1, wherein the cross-linked surfactants form a LLC phase.

14. The cross-linked LLC polymer of claim 13, wherein the cross-linked LLC polymer forms a bicontinuous cubic phase.

15. The cross-linked LLC polymer of claim 14, wherein the cross-linked LLC polymer forms an inverted bicontinuous cubic phase.

16. The cross-linked LLC polymer of claim 13, wherein the cross-linked LLC polymer forms a hexagonal phase

17. The cross-linked LLC polymer of claim 13, wherein the surfactant composition is such that L is —

CH₂CH₂—

(O—

CH₂—

CH₂)_p—

, p is 1 to 3.

18. A method of making a cross-linked lyotropic liquid crystal polymer, the method comprising the steps of:

a. preparing an LLC polymerization mixture comprising a plurality of polymerizable LLC surfactants according to claim 1, a polymerization initiator and a polar solvent selected from the group consisting of water, imidazolium based room temperature ionic liquids, and mixtures thereof, wherein the surfactant forms a lyotropic liquid crystal phase in combination with the solvent;

b. cross-linking at least some of the LLC surfactants.

19. The method of claim 18, wherein the degree of cross-linking is at least 90%.

20. The method of claim 18, wherein the surfactant composition is such that L is —

CH₂CH₂—

(O—

CH₂—

CH₂)_p—

, p is 1 to 3.

21. The method of claim 18, wherein the surfactant forms a bicontinuous cubic phase.

22. The method of claim 18, wherein the surfactant forms a hexagonal phase.

6. A lyotropic liquid crystal system comprising

a surfactant having the composition given by

Wherein X is an anion;

Y₁ and Y₂ each are a hydrophobic tail group comprising at least 10 carbon atoms;

Z₁, Z₂, Z₃ each are hydrogen or a hydrophobic tail group comprising from 1 to 12 carbon atoms; and

L is a spacer group which comprises an alkyl group having from 1 to 12 carbon atoms or comprises 1 to 6 ether groups; and

a polar solvent,

wherein the concentration of the surfactant is between 10 wt % and 100 wt % and the surfactant forms a lyotropic liquid crystal phase in combination with the solvent.

7. The lyotropic liquid crystal system of claim 6, wherein the surfactant forms a bicontinuous cubic phase in combination with the solvent.

8. The lyotropic liquid crystal system of claim 6, wherein the surfactant forms a hexagonal phase in combination with the solvent.

9. The lyotropic liquid crystal system of claim 6, wherein the polar solvent is selected from the group consisting of water, imidazolium based room temperature ionic liquids, and mixtures thereof.

10. The lyotropic liquid crystal system of claim 6, wherein L is —

(CH₂)_n, n is 1 to 10.

11. The lyotropic liquid crystal system of claim 6, wherein L is —

CH₂CH₂—

(O—

CH₂—

CH₂)_p—

, p is 1 to 3.

12. The lyotropic liquid crystal system of claim 6, wherein Y₁ and Y₂ further comprise a polymerizable group.