{'fraction_non_alphanumeric': 0.017651573292402148, 'fraction_numerical': 0.003837298541826554, 'mean_word_length': 5.827225130890052, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Preparation and characterization of sulfonated polyether ether ketone membranes for fuel cell applications: A comparison with Nafion® membranes

In this study, polyether ether ketone (PEEK) resin was sulfonated where the time of sulfonation reaction was varied at constant reaction temperature. After sulfonating PEEK, membranes of constant thickness were cast by solution casting method using a casting blade. Ion exchange capacity (IEC) of the membranes was determined by titration technique. Membrane stability and water uptake of the membranes were measured by immersing sPEEK membranes in distilled water at 23 and 100 o C for various soaking times. Surface morphology of the sPEEK membranes synthesized at various solvent evaporation temperatures was studied using optical microscopy. Mechanical properties of the membranes were measured in tensile mode using Universal testing machine (UTM). The results showed that the ion-exchange capacity, water absorption and tensile strength increased whereas dimensional stability and percentage elongation at break of the sPEEK membranes decreased by increasing the sulfonation time. Ion exchange capacity, dimensional stability, and tensile properties of the sulfonated PEEK membranes were also compared with the commercially available Nafion® membranes.