title: Nanocomposite membranes based on polybenzimidazole and ZrO2 for high-temperature proton exchange membrane fuel cells.
abstract: Owing to the numerous benefits obtained when operating proton exchange membrane fuel cells at elevated temperature (>100 °C), the development of thermally stable proton exchange membranes that demonstrate conductivity under anhydrous conditions remains a significant goal for fuel cell technology. This paper presents composite membranes consisting of poly[2,2'-(m-phenylene)-5,5'-bibenzimidazole] (PBI4N) impregnated with a ZrO2 nanofiller of varying content (ranging from 0 to 22 wt %). The structure-property relationships of the acid-doped and undoped composite membranes have been studied using thermogravimetric analysis, differential scanning calorimetry, dynamic mechanical analysis, wide-angle X-ray scattering, infrared spectroscopy, and broadband electrical spectroscopy. Results indicate that the level of nanofiller has a significant effect on the membrane properties. From 0 to 8 wt %, the acid uptake as well as the thermal and mechanical properties of the membrane increase. As the nanofiller level is increased from 8 to 22 wt % the opposite effect is observed. At 185 °C, the ionic conductivity of [PBI4N(ZrO2 )0.231 ](H3 PO4 )13 is found to be 1.04×10(-1)  S cm(-1) . This renders membranes of this type promising candidates for use in high-temperature proton exchange membrane fuel cells.
authors: Dipartimento di Scienze Chimiche, Universitá degli student di Padova, Via Marzolo, 1, 35131, Padova (Italy).
authors: Graeme
authors: G
authors: Nawn
authors: Giuseppe
authors: G
authors: Pace
authors: Sandra
authors: S
authors: Lavina
authors: Keti
authors: K
authors: Vezzù
authors: Enrico
authors: E
authors: Negro
authors: Federico
authors: F
authors: Bertasi
authors: Stefano
authors: S
authors: Polizzi
authors: Vito
authors: V
authors: Di Noto
mesh_terms: D001562:Benzimidazoles / Q000737:chemistry*; D011211:Electric Power Supplies; D004563:Electrochemistry; D055595:Mechanical Phenomena; D008567:Membranes, Artificial; D008958:Models, Molecular; D008968:Molecular Conformation; D053761:Nanocomposites / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry; D010756:Phosphoric Acids / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D011522:Protons; D013696:Temperature; D015040:Zirconium / Q000737:chemistry*
chemical_list: D001562:Benzimidazoles; D008567:Membranes, Artificial; D010756:Phosphoric Acids; D011108:Polymers; D011522:Protons; D015040:Zirconium; C030242:phosphoric acid; C028541:zirconium oxide
keywords: fuel cells; inorganic polymers; ion exchange; membranes; nanofillers