Anhydrous proton conductivity of sulfonated polysulfone/deep eutectic solvents (DESs) composite membranes: Effect of sulfonation degree and DES composition

• Published in: International journal of hydrogen energy Vol. 47; no. 2; pp. 1132 - 1143
• Main Authors: Mohammadi, Maryam, Karimi, Mohammad Bagher, Mohammadi, Fereidoon, Mehdipour-Ataei, Shahram
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 05.01.2022
• Subjects: Anhydrous proton conductivity; Composite membrane; Deep eutectic solvents; Sulfonated polysulfone; Sulfonation degree; Sulfonated polysulfone; Anhydrous proton conductivity; Deep eutectic solvents; Composite membrane; Sulfonation degree
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2021.10.056

The potential use of deep eutectic solvents (DESs) for anhydrous conductivity of sulfonated polysulfone membrane is presented. To this end, different molar ratios of sodium bromide as hydrogen bond acceptor (HBA) and ethylene glycol as hydrogen bond donor (HBD) are used for the synthesis of DESs. Two sulfonation degrees (DS) of 30 and 40% are also adjusted for the synthesis of sulfonated polysulfones. The synthesized DESs have suitable thermal stability as well as low viscosity to provide interconnected ionic pathways within the membranes. The proton conductivity of membranes is mainly influenced by the HBD/HBA molar ratio of DES as well as the DS of sulfonated polymer. The maximum proton conductivity of 301 mS/cm at 100 °C is obtained for the polymer with 40% DS containing a DES with a higher HBD/HBA molar ratio. The prepared composite membranes have great potential for fuel cell performance, especially in anhydrous conditions. [Display omitted] •The proton conductivity of sulfonated polysulfone/deep eutectic solvent was studied.•The solvent molar ratio and sulfonation degree were the variables of conductivity.•The proton conductivity of 301 mS/cm at 100 °C was gained for the optimum membrane.•These solvents were promising for anhydrous conductivity of sulfonated polysulfone.