Superomniphobic coatings and methods of preparation
A composition useful for producing a superomniphobic coating on a substrate, the composition comprising a colloidal suspension of a fluorinated siloxane in a non-silicon-containing fluorinated solvent. In some embodiments, the composition further comprises particles of a hydrophobized metal oxide, e.g., silicon oxide, wherein the hydrophobized metal oxide may be fluorinated. In some embodiments, the composition further comprises a non-silicon-containing fluorinated polymer. The invention is also directed to methods for making the above composition. The invention is also directed to methods for using the above-described composition for rendering a substrate superomniphobic. The aforesaid method comprises depositing a liquid coating solution onto a substrate to form a coated substrate, followed by subjecting the coated substrate to a drying step to remove a liquid phase of the liquid coating solution, wherein the liquid coating solution comprises a colloidal suspension of a fluorinated siloxane in a non-silicon-containing fluorinated solvent.
1. A composition useful for producing a superomniphobic coating on a substrate, the composition comprising a colloidal suspension of a fluorinated siloxane in a non-silicon-containing fluorinated solvent, wherein said fluorinated siloxane has the following structure:
wherein R F is a fluorinated alkyl group having at least three carbon atoms, and R′ is independently selected from hydrogen atom and alkyl groups having 1-6 carbon atoms, wherein said alkyl groups are optionally substituted with fluorine atoms.
2. The composition of claim 1 , wherein said non-silicon-containing fluorinated solvent has a melting point below 0° C.
3. The composition of claim 1 , wherein said non-silicon-containing fluorinated solvent is selected from the group consisting of a perfluorinated hydrocarbon having at least six carbon atoms; perfluorinated trialkylamine; perfluorodialkyl ether; fluorinated alcohol; and
perfluoroalkylated tetrahydrofuran.
4. The composition of claim 1 , wherein R F is a fluorinated alkyl group having at least five carbon atoms.
5. The composition of claim 1 , further comprising particles of a hydrophobized metal oxide.
6. The composition of claim 5 , wherein said hydrophobized metal oxide is silicon oxide.
7. The composition of claim 5 , wherein said hydrophobized metal oxide is fluorinated.
8. The composition of claim 1 , further comprising a non-silicon-containing fluorinated polymer.
9. The composition of claim 1 , further comprising particles of a hydrophobized metal oxide and a non-silicon-containing fluorinated polymer.
10. A method for rendering a substrate superomniphobic, the method comprising depositing the composition according to claim 1 onto said substrate to form a coated substrate, followed by subjecting the coated substrate to a drying step to remove a liquid phase of the composition according to claim 1 .
11. The method of claim 10 , wherein the non-silicon-coating fluorinated solvent is selected from the group consisting of a perfluorinated hydrocarbon having at least six carbon atoms; perfluorinated trialkylamine; perfluorodialkyl ether; fluorinated alcohols; and perfluoroalkylated tetrahydrofuran.
12. The method of claim 10 , wherein R F is a fluorinated alkyl group having at least five carbon atoms.
13. The method of claim 10 , wherein said colloidal suspension further comprises particles of a hydrophobized metal oxide.