Hybrid parylene-metal oxide layers for corrosion resistant coatings
Described herein is a composite coating on a substrate including a parylene layer deposited on a substrate surface of a substrate, a metal oxide layer covering the parylene layer, and a metal oxide, parylene hybrid layer formed between the metal oxide layer and the parylene layer.
1. A composite coating on a substrate, comprising:
a parylene layer deposited on a substrate surface of a substrate;
a metal oxide layer covering the parylene layer; and
a metal oxide, parylene hybrid layer formed between the metal oxide layer and the parylene layer, wherein a portion of the hybrid layer is located within an outer layer portion of the parylene layer, wherein the hybrid layer diffuses into the outer layer portion to at least a depth of one hundred nanometers in at least one location of the outer layer portion.
2. The composite coating of claim 1 , wherein the parylene layer is at least one of parylene A, parylene C, parylene N, parylene D, parylene VT-4 , parylene AF-4, or mixtures or derivations of parylene A, parylene C, parylene N, parylene D, parylene VT-4, parylene AF-4.
3. The composite coating of claim 1 , wherein the parylene layer is at least one of parylene C and parylene N.
4. The composite coating of claim 1 , wherein the metal oxide layer is formed by oxidation of a metal oxide precursor defined by formula I: [M]-(R 1 ) n , wherein:
M is a metal;
each R 1 is at least one of hydrogen, C 1 -C 12 alkyl, C 1 -C 12 alkoxide, halogen, C 1 -C 12 alkylamido, di-C 1 -C 12 alkylamido, optionally substituted cyclopentadienyl; and
n corresponds to the oxidation state of the metal.
5. The composite coating of claim 4 , wherein the metal is at least one of aluminum, gallium, magnesium, hafnium, silicon, tantalum, titanium, yttrium, zinc, and zirconium.
6. The composite coating of claim 4 , wherein the metal is aluminum.
7. The composite coating of claim 4 , wherein the metal is titanium.
8. The composite coating of claim 4 , wherein the metal is zinc.
9. The composite coating of claim 4 , wherein the metal is silicon.
10. The composite coating of claim 4 , wherein the metal is zirconium.
11. The composite coating of claim 5 , wherein at least one least one R 1 is hydrogen, C 1 -C 12 alkyl, or partially or completely halogenated C 1 -C 12 alkyl.
12. The composite coating of claim 5 , wherein at least one R 1 is a halogen selected from the group consisting of fluorine, chlorine, and bromine, or an alkoxide selected from the group consisting of iso-propoxide and butoxide.
13. The composite coating of claim 5 , wherein at least one R 1 is optionally substituted cyclopentadienyl.
14. A coated corrosive sensitive article comprising:
a corrosive sensitive article comprising a substrate surface; and
a composite coating comprising:
a parylene layer on the substrate surface;
a metal oxide layer covering the parylene layer; and
a metal oxide, parylene hybrid layer formed between the metal oxide layer and the parylene layer, wherein a portion of the hybrid layer is located within an outer layer portion of the parylene layer, wherein the hybrid layer diffuses into the outer layer portion to at least a depth of one hundred nanometers in at least one location of the outer layer portion.
15. The coated corrosive sensitive article of claim 14 , wherein the parylene layer is at least one of parylene A, parylene C, parylene N, parylene D, parylene VT-4, parylene AF-4, or mixtures or derivations of parylene A, parylene C, parylene N, parylene D, parylene VT-4, parylene AF-4.
16. A process for depositing a composite coating on a substrate, comprising:
applying a parylene layer to a substrate surface of a substrate;
depositing a metal oxide precursor onto a surface of the parylene layer, thereby covering the parylene layer;
diffusing the metal oxide precursor into an outer layer portion of the parylene layer; and
oxidizing the metal oxide precursor to form a metal oxide layer, parylene hybrid layer between the metal oxide layer and the parylene layer; wherein the hybrid layer diffuses into the outer layer portion to at least a depth of one hundred nanometers in at least one location of the outer layer portion.
17. The process of claim 16 , wherein the parylene layer is at least one of parylene A, parylene C, parylene N, parylene D, parylene VT-4, parylene AF-4, or mixtures or derivations of parylene A, parylene C, parylene N, parylene D, parylene VT-4, parylene AF-4.
18. The process of claim 17 , wherein a surface of the parylene layer is modified by infusion of a metal oxide precursor of the formula I: [M]-(R 1 ) n wherein:
M is a metal;
each R 1 is at least one of hydrogen, C 1 -C 12 alkyl, C 1 -C 12 alkoxide, halogen, C 1 -C 12 alkylamido, di-C 1 -C 12 alkylamido, optionally substituted cyclopentadienyl; and
n corresponds to the oxidation state of the metal.
19. The process of claim 16 , wherein the metal is at least one of aluminum, gallium, magnesium, hafnium, silicon, tantalum, titanium, yttrium, zinc, and zirconium.
20. The process of claim 16 , wherein the diffusing occurs at a temperature in the range of 20° C. to about 150° C.