Nanostructured articles and methods to make the same

1. A material comprising sub-micrometer particles and polymeric matrix, wherein the sub-micrometer particles consist of a first portion of the sub-micrometer particles dispersed within the polymeric matrix and a second portion dispersed in the polymeric matrix, wherein the material has a major surface, wherein the sub-micrometer particles have particle sizes of at least 75 nm, wherein the second portion of the sub-micrometer particles protrude from the major surface by up to 90 percent of their respective particle sizes, wherein the protruding sub-micrometer particles each have an exposed outer surface, and wherein less than 50 percent of the exposed outer surface is covered by organic material.

2. The material of claim 1 , wherein the sub-micrometer particles are covalently bonded to the polymeric matrix.

3. The material of claim 1 , wherein at least a portion of the polymeric matrix comprises at least one of tetrafluoroethylene, vinylfluoride, vinylidene fluoride, chlorotrifluoroethylene, perfluoroakoxy, fluorinated ethylene-propylene, ethylenetetrafluoroethylene, ethylenechlorotrifluoroethylene, perfluoropolyether, perfluoropolyoxetane, hexafluoropropylene oxide, siloxane, organosilicon, siloxides, silyl halides, ethylene oxide, propylene oxide, hydroxyl, hydroxylamine, carboxylic acid, —COONa, —SO 3 Na, —HCONCH 3 , —CONEt 2 , acrylamide, amine, ether, sulfonate, acrylic acid, maleic anhydride, vinyl acid, vinyl alcohol, vinylpyridine, vinypyrrolidone, acetylene, pyrrole, thiophene, aniline, phenylene sulfide, or imidazole.

4. The material of claim 1 , wherein at least some of the sub-micrometer particles are functionalized with at least one multifunctional silane coupling agent comprising silanol and at least one of acrylate, epoxy, or vinyl functional groups.

5. The material of claim 1 , wherein the sub-micrometer particles are present in a range from 10 percent to 70 percent by volume, based on the total volume of the material.

6. The material of claim 1 , wherein the sub-micrometer particles comprise at least one of carbon, metal, metal oxide, metal carbide, metal nitride, or diamond.

7. The material of claim 1 , wherein the sub-micrometer particles have particle sizes in a range from 75 nm to 500 nm.

8. The material of claim 1 , wherein the sub-micrometer particles have a bimodal distribution.

9. The material of claim 1 , wherein the portion of the sub-micrometer particles protruding from the major surface protrudes by up to 50 percent of their respective particle sizes.

10. The material of claim 1 , wherein the portion of the sub-micrometer particles protruding from the major surface protrudes in a range from 60 nm to 300 nm.

11. The material of claim 1 , wherein there is an average spacing between the protruding sub-micrometer particles is in a range from 5 nm to 300 nm.

12. The material of claim 1 , wherein the polymeric matrix comprises at least one of acrylate, urethane acrylate, methacrylate, polyester, epoxy, fluoropolymer, or siloxane.

13. The material of claim 1 having a change in reflection from the Durability Test of less than 2 percent.

14. The material of claim 1 that is a layer.

15. The layer of claim 14 having a thickness of at least 500 nm.

16. An article comprising a substrate having first and second generally opposed major surfaces with a layer of the material of claim 1 on the first major surface.

17. A method of making an article, the method comprising:

providing a layer comprising sub-micrometer particles dispersed in a polymeric precursor matrix;

at least one of drying or curing the layer; and

etching the dried or cured layer, as applicable, to provide the article of claim 16 .