Method for manufacturing reinforced composite membrane and reinforced composite membrane obtained thereby

A method for manufacturing a reinforced composite membrane, comprising the steps of:

• (A) pretreating a porous support;
• and
• (B) impregnating the pretreated porous support with a polymer electrolyte solution containing a solvent and a hydrocarbon-based polymer electrolyte,
• wherein the polymer electrolyte solution optionally further comprises a surfactant, and
• said pretreating is carried out by at least one of a method of dipping the porous support in a pretreatment solution containing at least one of K2Cr2O7 and KClO4 and a plasma treatment method.