Optimization and synthesis of plasma polymerized proton exchange membranes for direct methanol fuel cells

► A low-frequency after-glow capacitively coupled plasma (CCP) discharge technology is employed to prepare sulfonated plasma polymerized membranes. ► The properties of the obtained membranes strongly depend on the conditions used to the preparation of membranes. ► Membranes synthesized at preferable conditions possess highly cross-linked structures, higher sulfonation contents and chemical and mechanical stabilities, and therefore exhibit superior properties in their applications in direct methanol fuel cells.