Hydrophobic and icephobic coating

Abstract

Embodiments described herein relate to layered structures having a top surface which is hydrophobic for reducing the wetting of water or ice on the layered structure without requiring reapplication. In one or more embodiments, a layered structure is provided and includes a coating containing silicon, oxygen, and carbon disposed over a substrate and an interface disposed between the substrate and the coating. The substrate is at least partially transparent to visible light, a concentration of carbon in the coating is greater at a top surface of the coating than the interface, and the top surface of the coating is disposed on the opposite side of the coating than the interface.

What is claimed is: 
     
         1 . A layered structure, comprising:
 a coating comprising silicon, oxygen, and carbon disposed over a substrate; and   an interface disposed between the substrate and the coating;   wherein:
 the substrate is at least partially transparent to visible light; 
 a concentration of carbon in the coating is greater at a top surface of the coating than the interface; and 
 the top surface of the coating is disposed on the opposite side of the coating than the interface. 
   
     
     
         2 . The layered structure of  claim 1 , wherein the concentration of carbon in the coating is greater at the top surface of the coating by reducing a radio frequency power as the coating is deposited from the interface to the top surface. 
     
     
         3 . The layered structure of  claim 1 , wherein the concentration of carbon in the coating is less than 40 atomic percent. 
     
     
         4 . The layered structure of  claim 1 , wherein the coating on the substrate was deposited by a chemical vapor deposition process. 
     
     
         5 . The layered structure of  claim 1 , wherein the coating has a hardness in a range from about 1 GPa to about 10 GPa. 
     
     
         6 . The layered structure of  claim 1 , wherein the coating has a bulk modulus in a range from about 5 GPa to about 40 GPa. 
     
     
         7 . The layered structure of  claim 1 , wherein a plurality of water droplets disposed on the top surface of the coating makes a water contact angle with the top surface, the water contact angle is in a range from about 90° to about 120°. 
     
     
         8 . The layered structure of  claim 1 , wherein the thickness of the coating is in a range from about 1,000 Å to about 10 μm. 
     
     
         9 . The layered structure of  claim 1 , wherein the variation of concentration of carbon in the coating is substantially linear between the interface and the top surface. 
     
     
         10 . The layered structure of  claim 1 , wherein the concentration of carbon in the coating is in a range from about 3 atomic percent to about 25 atomic percent. 
     
     
         11 . The layered structure of  claim 1 , wherein the substrate comprises a windshield for a vehicle. 
     
     
         12 . The layered structure of  claim 1 , wherein the substrate comprises silicon and oxygen. 
     
     
         13 . The layered structure of  claim 1 , further comprising a second substrate disposed above the coating, the second substrate and the coating are separated by a non-zero distance or an interlayer. 
     
     
         14 . The layered structure of  claim 13 , further comprising a second coating formed over the second substrate. 
     
     
         15 . A layered structure, comprising:
 a coating comprising silicon, oxygen, and carbon disposed over a substrate; and   an interface disposed between the substrate and the coating;   wherein:
 the substrate is at least partially transparent to visible light; 
 a concentration of carbon in the coating is greater at a top surface of the coating than the interface; 
 the top surface of the coating is disposed on the opposite side of the coating than the interface; 
 the thickness of the coating is in a range from about 1,000 Å to about 10 μm; 
 the coating has a hardness in a range from about 1 GPa to about 10 GPa; and 
 the coating has a bulk modulus in a range from about 5 GPa to about 40 GPa. 
   
     
     
         16 . The layered structure of  claim 15 , wherein the concentration of carbon in the coating is greater at the top surface of the coating by reducing a radio frequency power as the coating is deposited from the interface to the top surface. 
     
     
         17 . The layered structure of  claim 15 , wherein a plurality of water droplets disposed on the top surface of the coating makes a water contact angle with the top surface, the water contact angle is in a range from about 90° to about 120°. 
     
     
         18 . The layered structure of  claim 15 , wherein the substrate comprises a windshield for a vehicle. 
     
     
         19 . The layered structure of  claim 15 , further comprising a second substrate disposed above the coating, the second substrate and the coating are separated by a non-zero distance or an interlayer. 
     
     
         20 . A layered structure, comprising:
 a coating comprising silicon, oxygen, and carbon disposed over a substrate; and   an interface disposed between the substrate and the coating;   wherein:
 the substrate is at least partially transparent to visible light; 
 the thickness of the coating is in a range from about 1,000 Å to about 10 μm; 
 a concentration of carbon in the coating is greater at a top surface of the coating than the interface by reducing a radio frequency power as the coating is deposited from the interface to the top surface; and 
 the top surface of the coating is disposed on the opposite side of the coating than the interface.