Superhydrophobic poly(dimethylsiloxane) and methods for making the same

1. A hydrophobic coating having a contact angle of at least about 150 degrees, which coating comprises:

a polymer substrate comprising poly(dimethyl) siloxane (PDMS) and a first linker incorporated therein at a specified surface density of from about 3×10 −4 to about 9 ×10 −8 units per nm 2 ;

a first polymer layer in contact with said first linker;

a second linker in contact with said first polymer layer; and

a second polymer layer in contact with said second linker.

2. The coating of claim 1 , wherein the first linker is incorporated at a surface density of about 1.0×10 −5 units per nm 2 .

3. The coating of claim 1 , wherein the first polymer layer is bonded to the first linker.

4. The coating of claim 1 , wherein the second linker is bonded to the first polymer layer.

5. The coating of claim 1 , wherein the second polymer layer is bonded to the second linker.

6. The coating of claim 1 , wherein the second polymer layer is the outermost layer on the article.

7. The coating of claim 1 , wherein the first polymer layer is bonded to the first linker by a carbon-carbon bond.

8. The coating of claim 1 , wherein the second linker is bonded to the first polymer layer by an ester bond.

9. The coating of claim 1 , wherein the second polymer layer is bonded to the second linker by a carbon-carbon bond.

10. The coating of claim 1 , wherein the first linker comprises an alkyl group with a terminal functional group.

11. The coating of claim 1 , wherein the first linker comprises a linear (C 6 -C 12 ) alkyl group with a terminal alpha-haloester group.

12. The coating of claim 1 , wherein the first polymer layer comprises a polyether.

13. The coating of claim 1 , wherein the first polymer layer comprises polyethylene glycol.

14. The coating of claim 1 , wherein the second linker comprises a carbonyl group.

15. The coating of claim 1 , wherein the second polymer layer comprises fluorine.

16. A hydrophobic coating having a contact angle of at least about 150°, which coating comprises:

a poly(dimethyl) siloxane substrate comprising a first linker incorporated therein at a surface density of from about 3×10 −4 to about 9×10 −8 units per nm 2 ;

a polyether layer in contact with said first linker;

a second linker in contact with to said polyether layer; and

a fluorinated polymer layer in contact with said second linker.

17. A method of making a hydrophobic coating having a contact angle of at least about 150 degrees, said method comprising:

1) providing a polymer substrate wherein a first linker is incorporated into the substrate at a surface density of from about 3×10 −4 to about 9×10 −8 units per nm 2 ;

2) contacting a monomer with said first linker under first polymerizing conditions to provide a first polymer layer bound to the polymer substrate through the first linker;

3) contacting a second linker with said first polymer layer under reaction conditions to provide a reactive surface; and

4) contacting a monomer with said reactive surface under second polymerizing conditions to provide the hydrophobic coating,

wherein providing a polymer substrate comprises polymerizing a mixture comprising at least one base monomer and a substantially low concentration of first linker to form a polymer substrate, and wherein the at least one base monomer is a poly(dimethyl-methylvinylsiloxane) prepolymer.

18. The method of claim 17 , wherein the mixture further comprises a second base monomer.

19. The method of claim 18 , wherein the ratio of first and second base monomer to first linker is about 10:1:10 −3 .