Hydrophilic/hydrophobic patterned surfaces and methods of making and using the same

• US 8,790,845 B2
• Filed: 06/04/2010
• Issued: 07/29/2014
• Est. Priority Date: 05/23/2007
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Xie, Tao
• Primary Examiner(s): Huff, Mark F
• Assistant Examiner(s): WILLS, MONIQUE M
• Application Number:
  US12/793,797
• Publication Number:
  US 20100239958A1
• Time in Patent Office: 1,516 Days
• Field of Search: 429/518, 428/195.1, 526/319
• US Class Current: 429/518
• CPC Class Codes: H01M 2008/1095 Fuel cells with polymeric electrolytes
• CPC Class Codes: H01M 8/0221 Organic resins; Organic polymers
• CPC Class Codes: H01M 8/0223 Composites
• CPC Class Codes: H01M 8/0228 in the form of layered or coated products
• CPC Class Codes: H01M 8/04171 using adsorbents, wicks or hydrophilic material
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y10T 428/24802 Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.]

Abstract

One embodiment includes a substrate having a plurality of molecular chains, each chain comprising a hydrophilic group, a hydrophobic segment, and a reversible crosslinker.

Claims

1. A product comprising a substrate comprising a plurality of molecular chains wherein each chain comprising a hydrophilic group, a hydrophobic segment, and a reversible crosslinker constructed and arranged to reversibly crosslink adjacent molecular chains to change a portion of the substrate from hydrophilic to hydrophobic or from hydrophobic to hydrophilic.

13. A product as set forth in claim 1 wherein each chain is bent over and wherein the hydrophilic or another group is attached to the substrate.

14. A product as set forth in claim 1 wherein each chain is bent over and wherein the hydrophilic group is attached to the substrate.

2. A product comprising a substrate, a plurality of molecular chains attached to the substrate, each chain comprising a hydrophilic group, a hydrophobic segment, and a photo-reversible crosslinker constructed and arranged to reversibly crosslink adjacent molecular chains to change a portion of the substrate from hydrophilic to hydrophobic or from hydrophobic to hydrophilic.

15. A product as set forth in claim 2 wherein each chain is bent over and wherein the hydrophilic or another group is attached to the substrate.

16. A product as set forth in claim 2 wherein each chain is bent over and wherein the hydrophilic group is attached to the substrate.

3. A product comprising a substrate having a reconstructable hydrophobic/hydrophilic patterned surface comprising a plurality of molecular chains, each chain containing a hydrophilic group, a hydrophobic segment and a photo-reversible crosslinked portion constructed and arranged to reversibly crosslink adjacent molecular chains to change a portion of the substrate from hydrophilic to hydrophobic or from hydrophobic to hydrophilic.

17. A product as set forth in claim 3 wherein each chain is bent over and wherein the hydrophilic or another group is attached to the substrate.

18. A product as set forth in claim 3 wherein each chain is bent over and wherein the hydrophilic group is attached to the substrate.

4. A product comprising a fuel cell bipolar plate comprising a substrate comprising a patterned surface comprising hydrophobic and hydrophilic regions comprising a plurality of molecular chains, each chain containing a hydrophilic group, a hydrophobic segment and a reversible crosslinked portion crosslinker constructed and arranged to reversibly crosslink adjacent molecular chains to change a portion of the surface from hydrophilic to hydrophobic or from hydrophobic to hydrophilic.

5. A product as set forth in claim 4 wherein chains in the hydrophilic region are stretched so that the hydrophilic group is furthest from the substrate to provide a surface of the hydrophilic groups.

6. A product as set forth in claim 4 wherein the chains in the hydrophilic group in the hydrophilic region are bent so that the hydrophilic group is attached to the substrate and a surface of the hydrophobic segment is provided.

7. A product as set forth in claim 4 wherein the bipolar plate does not include a reactant flow field defined by lands and channels therebetween.

8. A product as set forth in claim 4 wherein the bipolar plate comprising a reactant gas flow field is defined by at least two lands and a channel therebetween, the channel being defined at least in part by a floor surface and wherein the patterned surface is on the floor surface.

19. A product as set forth in claim 4 wherein each chain is bent over and wherein the hydrophilic or another group is attached to the substrate.

20. A product as set forth in claim 4 wherein each chain is bent over and wherein the hydrophilic group is attached to the substrate.

9. A product comprising a fuel cell bipolar plate having a reactant gas flow field defined therein by at least a plurality of lands and channels, the channel being at least partially defined by a surface, and a virtual microgroove over the surface comprising a plurality of molecular chains each comprising a hydrophilic group and a crosslinked portion crosslinker constructed and arranged to reversibly crosslink adjacent molecular chains to change a portion of the surface from hydrophilic to hydrophobic or from hydrophobic to hydrophilic.

10. A product as set forth in claim 9 wherein each molecular chain further comprises a hydrophobic segment.

11. A product as set forth in claim 9 wherein the crosslinked portion is reversibly crosslinked.

12. A product as set forth in claim 9 wherein the region defining the virtual microgroove has a width less than 50 μ

m.