Tuning Architecture in Polybenzimidazole Reinforced Membranes

Many fuel cell membranes are highly heterogeneous systems comprising mechanical and chemical reinforcing components, including porous polymer sheets, nanofibers or nanoparticles, as well as radical scavengers or hydrogen peroxide decomposition catalysts. In the last 10 years, significant attention has been devoted to 1D nanomaterials obtained by electrospinning. Several chemistries and compositions ranging from aliphatic or aromatic polymers to metal oxides and phosphates and morphologies from nanofibers to nanotubes have been employed to prepare nanocomposite membranes. Despite the significant advances realized, further improvements in ionomer membrane durability under operation are still required. In particular, it is crucial to control the heterogeneity induced by the nanofiber component and to strengthen the interface between them and the matrix. Specific interactions can improve the fiber/matrix interface with overall improvement of dimensional and mechanical properties. This presentation will briefly review the different approaches to fuel cell membrane reinforcement based on electrospun polymers and describe our recent advances with polybenzimidazole reinforcement of PFSAs.