Superhydrophobic films

Patent metadata

Field	Value
Publication number	US-9993948-B2
Application number	US-201514737565-A
Country	US
Kind code	B2
Filing date	Jun 12, 2015
Priority date	Oct 28, 2010
Publication date	Jun 12, 2018
Grant date	Jun 12, 2018

Abstract

Superhydrophobic films and methods of making such films are disclosed. More particularly, superhydrophobic films having durable nanostructures with high contrast ratios and various methods of producing such films are disclosed.

First claim

We claim:

1. A method of creating a superhydrophobic film, comprising:
providing a first film, the film comprising a plurality of microstructures on a first surface of the film and a layer of nanoposts on the microstructures;
coating the first film with a metal coating to create a metal mold of the first film;
separating the mold from the first film, wherein the nanoposts of the first film remain embedded in the mold after separating the mold;
etching the mold, such that the nanoposts embedded are etched away resulting in nanocavities in the mold; and
coating the etched mold with a curable composition, curing the composition to create a replica, and separating the replica to create a superhydrophobic film.

2. The method of claim 1 , wherein the etching is reactive ion etching.

3. The method of claim 1 , wherein the metal coating is applied by vacuum coating or plating.

4. A method of creating a superhydrophobic film, comprising:
providing a first film, the film comprising a plurality of microstructures on a first surface of the film;
applying a layer of nanoposts;
coating the first film in a curable composition, and curing the composition to create a negative of the first film;
separating the negative from the first film, wherein the nanoposts of the first film remain embedded in the negative after separation; and
etching the negative, resulting in a superhydrophobic film with a plurality of microstructures and nanocavities, the nanocavities having a length-to-opening ratio of at least 5 to 1.

5. The method of claim 4 , wherein the nanoposts are produced by self-assembling through annealing of a vacuum deposited organic pigment coating.

6. The method of claim 4 , wherein the nanocavities having a length-to-opening ratio of at least 10 to 1.

Assignees

• 3M Innovative Properties Co

Inventors

• Zhang Jun-Ying
• Smith Terry L
• Endres Berkan K
• Debe Mark K

Classifications

• C23F4/00

  Processes for removing metallic material from surfaces, not provided for in group C23F1/00 or C23F3/00 · CPC title

• B81C1/00531

  Dry etching · CPC title

• B81C1/00404

  Mask characterised by its size, orientation or shape · CPC title

• B81C1/00111

  Tips, pillars, i.e. raised structures (microneedles A61M37/0015) · CPC title

• B32B3/30

  characterised by a layer formed with recesses or projections, e.g. {hollows, grooves, protuberances, ribs (apertured layer B32B3/266; layer with cavities or internal voids B32B3/26)} · CPC title