Froth flotation is a process for selectively separating hydrophobic materials from hydrophilic.
They also exclude bacterial viruses and most hydrophobic toxic materials such as detergents.
Suberin is highly hydrophobic and a somewhat 'rubbery' material.
Some are better for cellulose-based fibers, others have higher affinity to hydrophobic materials like nylon, polyethylene terephthalate, polyacrylonitrile, etc.
Mr. Stern's answer is a dime-size piece of hydrophobic material that sticks on top of the coffee-lid vent hole.
Many very hydrophobic materials found in nature rely on Cassie's law and are biphasic on the submicrometer level with one component air.
Using silica nano-particles is also of interest to develop transparent hydrophobic materials for car windshields and self-cleaning windows.
Ideally, you would remove the water, by osmosis, from the specimen and replace it with some hydrophobic material such as paraffin.
First, a small aperture is created in a hydrophobic material such as Teflon.
The content of long hydrocarbon chains makes the material highly hydrophobic (resistant to wetting with water), making it more difficult to extinguish.