Thermal properties of phosphoric acid-doped polybenzimidazole membranes in water and methanol-water mixtures
The thermal properties of phosphoric acid-doped poly[2-2′-(m-phenylene)-5-5′ bi-benzimidazole] (PBI) and poly[2,5-benzimidazole] (ABPBI) membranes, ionomeric materials with promising properties to be used as electrolytes in direct methanol and in high temperature polymer electrolyte membrane (PEM) f...
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todo:paper_03787753_v195_n19_p6389_NoresPondal2023-10-03T15:33:16Z Thermal properties of phosphoric acid-doped polybenzimidazole membranes in water and methanol-water mixtures Nores-Pondal, F.J. Buera, M.P. Corti, H.R. ABPBI Fuel cells PBI Phosphoric acid Thermal properties Water ABPBI Benzimidazoles Cold environment Direct methanol DSC scans Frozen water High temperature polymer electrolyte membranes Ionomeric materials Liquid water Methanol-water mixtures Nafion membrane PBI Polybenzimidazole Polymeric matrices Relative humidities Solvent desorption Temperature range Temperature regions Thermal properties Thermal relaxation Very low temperatures Acids Atmospheric humidity Cold working Desorption Differential scanning calorimetry Electrolytes Fuel cells Gas fuel purification Glass Glass transition Liquids Materials properties Methanol Methanol fuels Mixtures Phosphoric acid Polymers Thermodynamic properties Membranes The thermal properties of phosphoric acid-doped poly[2-2′-(m-phenylene)-5-5′ bi-benzimidazole] (PBI) and poly[2,5-benzimidazole] (ABPBI) membranes, ionomeric materials with promising properties to be used as electrolytes in direct methanol and in high temperature polymer electrolyte membrane (PEM) fuel cells, were studied by means of differential scanning calorimetry (DSC) technique in the temperature range from -145 °C to 200 °C. The DSC scans of samples equilibrated in water at different relative humidities (RH) and in liquid water-methanol mixtures were analyzed in relation to glass transition, water crystallization/melting and solvent desorption in different temperature regions. The thermal relaxation observed in the very low temperature region could be ascribed to the glass transition of the H3PO4-H2O mixture confined in the polymeric matrix. After cooling the samples up to -145 °C, frozen water was detected in PBI and ABPBI at different RH, although at 100% RH less amount of water had crystallized than that observed in Nafion membranes under the same conditions. Even more important is the fact that the freezing degree of water is much lower in ABPBI membranes equilibrated in liquid water-methanol mixtures than that observed for PBI and, in a previous study, for Nafion. Thus, apart from other well known properties, acid-doped ABPBI emerges as an excellent ionomer for applications in direct methanol fuel cells working in cold environments. © 2010 Elsevier B.V. All rights reserved. Fil:Buera, M.P. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Corti, H.R. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_03787753_v195_n19_p6389_NoresPondal |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
ABPBI Fuel cells PBI Phosphoric acid Thermal properties Water ABPBI Benzimidazoles Cold environment Direct methanol DSC scans Frozen water High temperature polymer electrolyte membranes Ionomeric materials Liquid water Methanol-water mixtures Nafion membrane PBI Polybenzimidazole Polymeric matrices Relative humidities Solvent desorption Temperature range Temperature regions Thermal properties Thermal relaxation Very low temperatures Acids Atmospheric humidity Cold working Desorption Differential scanning calorimetry Electrolytes Fuel cells Gas fuel purification Glass Glass transition Liquids Materials properties Methanol Methanol fuels Mixtures Phosphoric acid Polymers Thermodynamic properties Membranes |
| spellingShingle |
ABPBI Fuel cells PBI Phosphoric acid Thermal properties Water ABPBI Benzimidazoles Cold environment Direct methanol DSC scans Frozen water High temperature polymer electrolyte membranes Ionomeric materials Liquid water Methanol-water mixtures Nafion membrane PBI Polybenzimidazole Polymeric matrices Relative humidities Solvent desorption Temperature range Temperature regions Thermal properties Thermal relaxation Very low temperatures Acids Atmospheric humidity Cold working Desorption Differential scanning calorimetry Electrolytes Fuel cells Gas fuel purification Glass Glass transition Liquids Materials properties Methanol Methanol fuels Mixtures Phosphoric acid Polymers Thermodynamic properties Membranes Nores-Pondal, F.J. Buera, M.P. Corti, H.R. Thermal properties of phosphoric acid-doped polybenzimidazole membranes in water and methanol-water mixtures |
| topic_facet |
ABPBI Fuel cells PBI Phosphoric acid Thermal properties Water ABPBI Benzimidazoles Cold environment Direct methanol DSC scans Frozen water High temperature polymer electrolyte membranes Ionomeric materials Liquid water Methanol-water mixtures Nafion membrane PBI Polybenzimidazole Polymeric matrices Relative humidities Solvent desorption Temperature range Temperature regions Thermal properties Thermal relaxation Very low temperatures Acids Atmospheric humidity Cold working Desorption Differential scanning calorimetry Electrolytes Fuel cells Gas fuel purification Glass Glass transition Liquids Materials properties Methanol Methanol fuels Mixtures Phosphoric acid Polymers Thermodynamic properties Membranes |
| description |
The thermal properties of phosphoric acid-doped poly[2-2′-(m-phenylene)-5-5′ bi-benzimidazole] (PBI) and poly[2,5-benzimidazole] (ABPBI) membranes, ionomeric materials with promising properties to be used as electrolytes in direct methanol and in high temperature polymer electrolyte membrane (PEM) fuel cells, were studied by means of differential scanning calorimetry (DSC) technique in the temperature range from -145 °C to 200 °C. The DSC scans of samples equilibrated in water at different relative humidities (RH) and in liquid water-methanol mixtures were analyzed in relation to glass transition, water crystallization/melting and solvent desorption in different temperature regions. The thermal relaxation observed in the very low temperature region could be ascribed to the glass transition of the H3PO4-H2O mixture confined in the polymeric matrix. After cooling the samples up to -145 °C, frozen water was detected in PBI and ABPBI at different RH, although at 100% RH less amount of water had crystallized than that observed in Nafion membranes under the same conditions. Even more important is the fact that the freezing degree of water is much lower in ABPBI membranes equilibrated in liquid water-methanol mixtures than that observed for PBI and, in a previous study, for Nafion. Thus, apart from other well known properties, acid-doped ABPBI emerges as an excellent ionomer for applications in direct methanol fuel cells working in cold environments. © 2010 Elsevier B.V. All rights reserved. |
| format |
JOUR |
| author |
Nores-Pondal, F.J. Buera, M.P. Corti, H.R. |
| author_facet |
Nores-Pondal, F.J. Buera, M.P. Corti, H.R. |
| author_sort |
Nores-Pondal, F.J. |
| title |
Thermal properties of phosphoric acid-doped polybenzimidazole membranes in water and methanol-water mixtures |
| title_short |
Thermal properties of phosphoric acid-doped polybenzimidazole membranes in water and methanol-water mixtures |
| title_full |
Thermal properties of phosphoric acid-doped polybenzimidazole membranes in water and methanol-water mixtures |
| title_fullStr |
Thermal properties of phosphoric acid-doped polybenzimidazole membranes in water and methanol-water mixtures |
| title_full_unstemmed |
Thermal properties of phosphoric acid-doped polybenzimidazole membranes in water and methanol-water mixtures |
| title_sort |
thermal properties of phosphoric acid-doped polybenzimidazole membranes in water and methanol-water mixtures |
| url |
http://hdl.handle.net/20.500.12110/paper_03787753_v195_n19_p6389_NoresPondal |
| work_keys_str_mv |
AT norespondalfj thermalpropertiesofphosphoricaciddopedpolybenzimidazolemembranesinwaterandmethanolwatermixtures AT bueramp thermalpropertiesofphosphoricaciddopedpolybenzimidazolemembranesinwaterandmethanolwatermixtures AT cortihr thermalpropertiesofphosphoricaciddopedpolybenzimidazolemembranesinwaterandmethanolwatermixtures |
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