Reverse osmosis membranes, which are made with PFSA ionomer and ePTFE

A method for forming a membrane comprising a step of dissolving a lithium salt in a solution which comprises an ionomer comprising protogenic group to form a modified solution. A membrane is formed from the solution containing the lithium salt and the ionomer, comprising protic groups. The membrane is dried and then contacted with water to form a plurality of pores therein.