US Patent 8177979 - Water filtration with asymmetric nanotube membranes

http://www.freepatentsonline.com/8177979.html

NanOasis Technologies is a company using carbon nanotubes to manufacture reverse osmosis membranes to enable water desalination and purification. This patent includes some basic claims to NanoOasis's approach. Claim 1 reads:

1. A water filtration method, comprising

passing water through a membrane to filter the water,

wherein the membrane comprises an asymmetric porous polymer and terminating on one side in a skin, with open-ended nanotubes embedded in said skin and protruding through opposite surfaces of said skin to provide fluid communication through each of said nanotubes through said membrane, and

said skin forming a substantially impermeable barrier around said nanotubes, said membrane having pores increasing in diameter with increasing distance from said skin.