Proton conducting membranes based on semi-interpenetrating polymer network of Nafion® and polybenzimidazole 
(5473-5481) Polymer 51 #23 (2010)
Guan et al ofTongji University prepared the interpenetrating network during membrane formation using N-vinylimidazole as the crosslinker.  The composite membranes exhibit excellent thermal stability, high-dimensional stability, and significantly improved mechanical properties compared with Nafion®212. The benzimidazole structure of PBI and the acidic component of Nafion® provide the possibility for the proton mobility via structure diffusion involving proton transfer between the heterocycles with a corresponding reorganization of the hydrogen bonded network  (RDC 12/17/2010)