Superhydrophobic and self-cleaning substrate and a method of coating

Patent metadata

Field	Value
Publication number	US-10150140-B2
Application number	US-201615387142-A
Country	US
Kind code	B2
Filing date	Dec 21, 2016
Priority date	Feb 9, 2016
Publication date	Dec 11, 2018
Grant date	Dec 11, 2018

Abstract

A superhydrophobic and self-cleaning surface including a substrate and a superhydrophobic layer. The superhydrophobic layer having a reacted form of octadecyltrichlorosilane. The octadecyltrichlorosilane is disposed on and crosslinked to a surface of the substrate via surface hydroxyl groups. The surface exhibits a rms roughness of 40 nm to 60 nm, a water contact angle of 155° to 180°, and a contact angle hysteresis of less than 15°. A method of preparing the substrate with a superhydrophobic and self-cleaning surface including treating a substrate with a plasma treatment, contacting the substrate with water or an alcohol to form an hydroxylated substrate, contacting the hydroxylated substrate with a solution of octadecyltrichlorosilane in an alkane solvent at a concentration in the range of 0.05 M to 0.3 M, and drying the solution on to the substrate under ambient air to form the superhydrophobic and self-cleaning surface on the substrate.

First claim

The invention claimed is:

1. A substrate with a superhydrophobic and self-cleaning surface, comprising:
a substrate comprising a surface modified with hydroxyl groups; and
a superhydrophobic layer, which is a 3-dimensional polysiloxane network of cylindrical fibers having a diameter of 45 nm to 100 nm with pores in between the cylindrical fibers, formed from vertical and horizontal polymerization of octadecyltrichlorosilane;
wherein the superhydrophobic layer is disposed on and crosslinked to the surface of the substrate via the hydroxyl groups; and
wherein the substrate with the superhydrophobic and self-cleaning surface has a root mean square roughness of 40 nm to 60 nm, a water contact angle of 155° to 180°, and a contact angle hysteresis of less than 15°.

2. The substrate with a superhydrophobic and self-cleaning surface of claim 1 , wherein the substrate is a glass, a hard plastic, a non-woven fabric, a cotton fabric, a non-woven synthetic polymer fabric, or a combination thereof.

3. The substrate with a superhydrophobic surface and self-cleaning surface of claim 1 , wherein a height of the cylindrical fibers from peak to valley is in the range of 0.9 nanometers to 500 nanometers.

4. The substrate with a superhydrophobic and self-cleaning surface of claim 1 , wherein the pores have a pore size in the range of 140 nm to 260 nm.

5. The substrate with a superhydrophobic and self-cleaning surface of claim 1 , which is resistant to particles having a size of at least 0.8 micron.

6. A method of preparing the substrate with a superhydrophobic and self-cleaning surface of claim 1 , the method comprising:
treating the substrate with a plasma treatment under a reduced pressure of 0.5 atm to vacuum;
removing the substrate from the reduced pressure and contacting the substrate with water, an alcohol, or both to form a hydroxylated substrate;
contacting the hydroxylated substrate with a solution comprising octadecyltrichlorosilane and an alkane solvent, wherein a concentration of the octadecyltrichlorosilane in the alkane solvent is in the range of 0.05 M to 0.3 M; and
drying the solution on a surface of the substrate under air to form the substrate with the superhydrophobic and self-cleaning surface.

7. The method of claim 6 , wherein the plasma treatment is at least one selected from the group consisting of an oxygen plasma, an argon plasma treatment, and a nitrogen plasma treatment.

8. The method of claim 6 , wherein the alkane is hexane.

9. The method of claim 6 , wherein the dying is under a heated air stream.

10. The method of claim 6 , wherein the treating is for 1 minute to 5 minutes under a vacuum.

11. The method of claim 6 , further comprising repeating the contacting and the drying.

12. The method of claim 6 , wherein the substrate is a glass, a hard plastic, a non-woven fabric, a cotton fabric, a non-woven synthetic polymer fabric, or a combination thereof.

Assignees

• Univ King Fahd Pet & Minerals

Inventors

• Matin Asif
• Merah Necar

Classifications

• B05D2203/35

  Glass · CPC title

• B05D3/142

  Pretreatment · CPC title

• B05D2518/12

  Ceramic precursors (polysiloxanes, polysilazanes) · CPC title

• B05D5/08 Primary

  to obtain an anti-friction or anti-adhesive surface (rendering particulate materials free-flowing in general, e.g. making them hydrophobic B01J2/30) · CPC title

• B05D2201/00

  Polymeric substrate or laminate · CPC title