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

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.

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.

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.

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.

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 μm.

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.

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.

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.

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.