The present disclosure relates to a process for neutralizing a sulfonated block copolymer with a metal compound, to metal-neutralized block copolymers, and to various articles comprising the metal-neutralized block copolymers, e.g., in form of a water vapor permeable membrane which comprises the metal-neutralized block copolymers. The present disclosure further relates to a means and a method for storing and stabilizing a polar component such as a metal compound in a non-polar liquid phase by immuring the polar component in micelles of the sulfonated block copolymer in the non-polar liquid phase.