Superhydrophobic coatings
A superhydrophobic coating can have a water contact angle greater than 150°. The coating can remain superhydrophobic after being immersed in water for one week.
1 . A superhydrophobic surface comprising:
a high roughness polyelectrolyte multilayer arranged on a substrate;
a plurality of nanometer-scale features associated with the high roughness polyelectrolyte multilayer; and
a hydrophobic coating over the substrate.
2 . The surface of claim 1 , wherein the nanometer-scale features include a nanoparticle.
3 . The surface of claim 1 , wherein the high roughness polyelectrolyte multilayer includes poly(allylamine hydrochloride).
4 . The surface of claim 1 , wherein the high roughness polyelectrolyte multilayer includes poly(acrylic acid).
5 . The surface of claim 1 , wherein the high roughness polyelectrolyte multilayer is a porous polyelectrolyte multilayer.
6 . The surface of claim 5 , wherein the polyelectrolyte multilayer includes a pore between 0.2 micrometers and 20 micrometers in size.
7 . The surface of claim 1 , wherein the plurality of nanometer-scale features includes a nanoparticle between 1 nanometer and 100 nanometers in size.
8 . The surface of claim 1 , wherein the plurality of nanometer-scale features includes a silica nanoparticle, a silver nanoparticle, a gold nanoparticle, or a polystyrene nanoparticle.
9 . The surface of claim 1 , wherein the surface has an advancing water contact angle of greater than 150°.
10 . The surface of claim 9 , wherein the surface has a receding water contact angle of greater than 150°.
11 . The surface of claim 1 , wherein the surface has an advancing water contact angle and a receding water contact angle that differ by no more than 5°.
12 . The surface of claim 1 , wherein the surface remains superhydrophobic after a one-week immersion in water.
13 . The surface of claim 1 , wherein the hydrophobic coating includes a hydrophobic silane.
14 . The surface of claim 1 , wherein the hydrophobic coating includes a fluoropolymer.
15 . The surface of claim 1 , wherein the substrate is glass.
16 . The surface of claim 1 , wherein the substrate is plastic.
17 . A superhydrophobic surface comprising a polyelectrolyte multilayer arranged on a substrate, wherein the surface has an advancing water contact angle of greater than 150° and a receding water contact angle, and the advancing water contact angle differs from the receding water contact by less than 5°.
18 . The surface of claim 17 , wherein the polyelectrolyte multilayer is a high roughness polyelectrolyte multilayer.
19 . The surface of claim 17 , wherein the polyelectrolyte multilayer includes poly(allylamine hydrochloride).
20 . The surface of claim 17 , wherein the polyelectrolyte multilayer includes poly(acrylic acid).
21 . The surface of claim 20 , wherein the polyelectrolyte multilayer is a porous polyelectrolyte multilayer.
22 . The surface of claim 21 , wherein the polyelectrolyte multilayer includes a pore between 0.2 micrometers and 20 micrometers in size.
23 . The surface of claim 17 , further comprising a plurality of nanometer-scale features associated with the polyelectrolyte multilayer.
24 . The surface of claim 23 , wherein in the plurality of nanometer-scale features includes a nanoparticle between 1 nanometer and 100 nanometers in size.
25 . The surface of claim 17 , further comprising a hydrophobic coating over the substrate.
26 . The surface of claim 25 , wherein the hydrophobic coating includes a hydrophobic silane.
27 . The surface of claim 25 , wherein the hydrophobic coating includes a fluoropolymer.
28 . The surface of claim 17 , wherein the surface remains superhydrophobic after a one-week immersion in water.
29 . The surface of claim 17 , wherein the substrate is glass.
30 . The surface of claim 17 , wherein the substrate is plastic.
31 . A superhydrophobic surface comprising:
a high roughness polyelectrolyte multilayer arranged on a substrate;
a plurality of nanometer-scale features associated with the high roughness polyelectrolyte multilayer; and
a hydrophobic coating over the substrate;
wherein the surface has an advancing water contact angle of greater than 150° and a receding water contact angle, and the advancing water contact angle differs from the receding water contact by less than 5°.
32 . The surface of claim 31 , wherein the surface remains superhydrophobic after a one-week immersion in water.
33 . A superhydrophilic surface comprising a polyelectrolyte multilayer arranged on a substrate.
34 . The surface of claim 33 , wherein the polyelectrolyte multilayer is a porous polyelectrolyte multilayer.
35 . The surface of claim 33 , wherein the polyelectrolyte multilayer includes a pore between 0.2 micrometers and 20 micrometers in size.
36 . The surface of claim 33 , wherein the polyelectrolyte multilayer includes poly(allylamine hydrochloride).
37 . The surface of claim 33 , wherein the polyelectrolyte multilayer includes poly(acrylic acid).
38 . The surface of claim 33 , further comprising a plurality of nanometer-scale features associated with the polyelectrolyte multilayer.
39 . The surface of claim 38 , wherein the plurality of nanometer-scale features includes a nanoparticle between 1 nanometer and 100 nanometers in size.
40 . The surface of claim 38 , wherein the plurality of nanometer-scale features includes a silica nanoparticle, a silver nanoparticle, a gold nanoparticle, or a polystyrene nanoparticle.
41 . The surface of claim 33 , wherein the surface has a water contact angle of less than 5°.
42 . A surface comprising a polyelectrolyte multilayer arranged on a substrate, wherein the surface includes a superhydrophobic region and a superhydrophilic region.
43 . The surface of claim 42 , wherein the superhydrophobic region or the superhydrophilic region forms a pattern on the surface.
44 . A method of making a superhydrophobic surface comprising coating a superhydrophilic surface with a hydrophobic material.
45 . A method of altering the wettability of a surface comprising:
providing a substrate having a surface coated with a coating including a polyelectrolyte;
contacting the coating including the polyelectrolyte with a roughness-inducing medium to form increase the roughness of the coating; and
introducing a plurality of nanometer-scale features to the coating to form a composite coating.
46 . The method of claim 45 , further comprising forming a hydrophobic coating over the composite layer.
47 . The method of claim 45 , wherein introducing a plurality of nanometer-scale features includes contacting the coating with a plurality of nanoparticles.
48 . The method of claim 45 , wherein providing a substrate having a surface coated with a coating including a polyelectrolyte includes contacting the substrate with a polyelectrolyte.
49 . The method of claim 48 , wherein the polyelectrolyte is a component of an aqueous solution.
50 . The method of claim 49 , wherein the aqueous solution includes poly(allylamine hydrochloride).
51 . The method of claim 49 , wherein the aqueous solution includes poly(acrylic acid).
52 . The method of claim 45 , wherein the roughness-inducing medium is an aqueous medium.
53 . The method of claim 45 , wherein contacting the coating including the polyelectrolyte with a roughness-inducing medium includes forming a pore in the coating.
54 . The method of claim 53 , wherein contacting the coating including the polyelectrolyte with a roughness-inducing medium includes forming a pore between 0.2 micrometers and 20 micrometers in size in the coating
55 . The method of claim 45 , further comprising crosslinking the coating including the polyelectrolyte.
56 . The method of claim 55 , wherein crosslinking the coating includes heating the coating.
57 . The method of claim 47 , wherein the plurality of nanoparticles includes a nanoparticle between 1 nanometer and 100 nanometers in size.
58 . The method of claim 47 , wherein the plurality of nanoparticles includes a silica nanoparticle, a silver nanoparticle, a gold nanoparticle, or a polystyrene nanoparticle.
59 . The method of claim 46 , wherein forming a hydrophobic coating over the composite coating includes contacting the composite coating with a hydrophobic silane.
60 . The method of claim 46 , wherein forming a hydrophobic coating over the composite coating includes contacting the composite coating with a fluoropolymer.
61 . The method of claim 45 , wherein the substrate is glass.
62 . The method of claim 45 , wherein the substrate is plastic.