| abstract |
The present invention discloses fluoropolymer coated membranes and methods for making and using these membranes. The fluoropolymer coated membranes are prepared by coating a porous asymmetric membrane layer with a thin layer of fluoropolymer coating. The porous asymmetric membrane layer comprises an asymmetric cellulosic membrane, an asymmetric polymer membrane, or an asymmetric molecular sieve/polymer mixed matrix membrane with a low selectivity and high permeance. The fluoropolymer coating improves the selectivity of the porous asymmetric membrane layer and maintains the membrane performance with time. The fluoropolymer coated membranes are suitable for a variety of liquid, gas, and vapor separations such as desalination of water by reverse osmosis, non-aqueous liquid separation such as deep desulfurization of gasoline and diesel fuels, ethanol/water separations, pervaporation dehydration of aqueous/organic mixtures, CO 2 /CH 4 , CO 2 /N 2 , H 2 /CH 4 , O 2 /N 2 , olefin/paraffin, iso/normal paraffins separations, and other light gas mixture separations. |