Nanoporous media templated from unsymmetrical amphiphilic porogens

• US 7,960,442 B2
• Filed: 04/20/2005
• Issued: 06/14/2011
• Est. Priority Date: 04/20/2005
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Lee, Victor Yee-Way, Cha, Jennifer Nam, Volksen, Willi, Kim, Ho-Cheol, Miller, Robert Dennis, Hedrick, James Lupton, Dubois, Geraud Jean-Michel, Magbitang, Teddie Peregrino
• Primary Examiner(s): Eashoo; Mark
• Assistant Examiner(s): MCCULLEY, MEGAN CASSANDRA
• Application Number:
  US11/111,343
• Publication Number:
  US 20060241194A1
• Time in Patent Office: 2,246 Days
• Field of Search: 521/77
• US Class Current: 521/77
• CPC Class Codes: C08G 63/66 Polyesters containing oxygen in the form of ether groups C08G63/42, C08G63/58 take precedence
• CPC Class Codes: C08J 9/26 by elimination of a solid phase from a macromolecular composition or article, e.g. leaching out
• CPC Class Codes: C08K 5/5419 containing at least one Si—C bond
• CPC Class Codes: C08L 67/00 Compositions of polyesters obtained by reactions forming a carboxylic ester link in the main chain of polyester-amides C08L77/12; of polyester-imides C08L79/08; Compositions of derivatives of such polymers
• CPC Class Codes: C08L 83/00 Compositions of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon only; Compositions of derivatives of such polymers
• CPC Class Codes: C08L 83/04 Polysiloxanes

Abstract

Substantially or roughly spherical micellar structures useful in the formation of nanoporous materials by templating are disclosed. A roughly spherical micellar structure is formed by organization of one or more spatially unsymmetric organic amphiphilic molecules. Each of those molecules comprises a branched moiety and a second moiety. The branched moiety can form part of either the core or the surface of the spherical micellar structure, depending on the polarity of the environment. The roughly spherical micellar structures form in a thermosetting polymer matrix. They are employed in a templating process whereby the amphiphilic molecules are dispersed in the polymer matrix, the matrix is cured, and the porogens are then removed, leaving nanoscale pores.

Claims

1. A method of producing a nanoporous material, comprising:

providing a medium into which an amphiphile is dispersed, the medium comprising both solvent and matrix material;

dispensing the medium onto a substrate;

removing the solvent, thereby forming a solid structure that comprises the amphiphile dispersed in the matrix material; and

generating porosity in the matrix material via a templating mechanism by decomposing the amphiphile, thereby leaving porous regions in the matrix material,

wherein the amphiphile comprises at least one branched moiety attached to one linear polymeric moiety, wherein the linear polymeric moiety has a degree of polymerization of between 50 and 500, and one of either the branched moiety or the linear polymeric moiety is lyophilic, and the other is lyophobic.

2. A method of producing a nanoporous material according to claim 1, wherein the weight percentage of the amphiphile which is dispersed in the total weight of amphiphile plus matrix material lies between about 1% and about 30%.

3. The method of producing a nanoporous material according to claim 2, wherein the weight percentage of the amphiphile which is dispersed in the total weight of amphiphile plus matrix material is about 20%.

4. A method of producing a nanoporous material according to claim 1, wherein the pores formed by the method have an average diameter of from about 1 nm to about 50 nm.

5. A method of producing a nanoporous material according to claim 1, wherein the pores formed by the method have an average diameter of from about 1 nm to about 10 nm.

6. A method of producing a nanoporous material according to claim 1, wherein the pores formed by the method have an average diameter of from about 2 nm to about 8 nm.

7. A method of producing a nanoporous material according to claim 1, wherein the pores formed by the method are uniformly distributed throughout the matrix material.

8. A method of producing a nanoporous material according to claim 1, wherein the porous matrix material so formed has a dielectric constant of between 1.0 and 3.0.

9. A method of producing a nanoporous material according to claim 1, wherein the porous matrix material so formed has a dielectric constant of between 1.5 and 2.0.

10. The method of producing a nanoporous material according to claim 1, wherein the volumetric porosity of the nanoporous material is between 1% and 35%.

11. The method of producing a nanoporous material according to claim 1, wherein the linear polymeric moiety comprises polyethylene glycol or polypropylene glycol.

12. The method of producing a nanoporous material according to claim 1, wherein the branched moiety comprises a dendrimer.

13. The method of producing a nanoporous material according to claim 1, wherein the matrix material comprises an organosilicate.

14. The method of producing a nanoporous material according to claim 1, wherein the amphiphile forms a micellar structure.

15. The method of producing a nanoporous material according to claim 1, wherein the branched moiety is chosen to be compatible with the matrix.

16. The method of claim 1, wherein the amphiphile has the structure.

17. The method of claim 16, wherein n is 110.

18. The method of claim 1, wherein the at least one branched moiety is lyophobic, and wherein the linear polymeric moiety is lyophilic.

19. The method of claim 18, wherein the amphiphile forms a micellar structure in the medium, and wherein the linear polymeric moiety lies on the outside of the micellar structure.

20. The method of claim 1, wherein the amphiphile is spatially unsymmetric and is prepared by a method comprising:

(1) preparation of the compound

21. The method of claim 20, wherein n is 110.