I have not researched the latest papers on this, but researchgate had some links that mostly center on hydrophobic nano-coatings which could be applied after manufacture and molecularly or covalently bond to a surface. Effectiveness and durability are the issues.

https://www.nanoshell.co.uk/products/details/...otector/4/

https://www.asme.org/engineering-topics/artic...efficiency

https://www.chemours.com/Teflon_Industrial/en...k15778.pdf

http://science.sciencemag.org/content/347/6226/1132