https://phys.org/news/2018-10-scientists-oil-resistant-filter-technology.html

"One of the best ways to clean oily water is with membranes," said Seth Darling, Director of the Institute for Molecular Engineering at Argonne. "The problem is that the oil sticks on the membrane and clogs the holes until the membrane stops working. Today, if people have an oil-fouled membrane, either they replace it or they try to clean it with harsh chemicals to wash away the oil."

The scientists used a method called atomic layer deposition, which uses chemical vapors to deposit a very thin coating of the metal oxide on all of the filter membrane surfaces. They experimented using different metal oxides on off-the-shelf commercial polymer membranes to find which ones worked the best. The team published the results in ACS Nano on August 14.