The Effect of Salty Environments on the Degradation Behavior and Mechanical Properties of Nafion Membranes

Abstract

The application of proton-exchange membrane fuel cells (PEMFCs) in maritime transportation is currently in the spotlight due to stringent emissions regulations and the establishment of a carbon trading system. However, salt in the marine environment can accelerate the degradation of proton-exchange membranes (PEM), which are the core component of PEMFCs. In this study, the effect of the NaCl concentration and temperature on the degradation of Nafion, the benchmark PEMFC membrane, was analyzed ex situ by accelerated degradation using Fenton’s test. The membrane properties were studied by mass change, fluoride ion emission, FTIR spectroscopy, and tensile test. The results showed that the degradation of Nafion membranes increased with the increase in temperature and NaCl concentration. Further studies revealed that Nafion produces C=O bonds during the degradation process. Additionally, it was found that sodium ions replace hydrogen ions in degraded Nafion fragments based on analysis of the weight change, and the rate of substitution increases with increasing temperature. A better understanding of the degradation behavior of Nafion in salty environments will lead to the advanced manufacturing of PEM for applications of PEMFCs in maritime transportation.

Examining the Effect of Ionizing Radiations in Ion-Exchange Membranes of Interest in Biomedical Applications

“…We found that this mass loss was not observed in similar experiments using pure water with any one of the non-irradiated samples. Some studies showed that the presence of Na + affects the intramembrane transport properties [ 26 , 27 ]. Madhav et al [ 26 ] used accelerated degradation via Fenton´s test to examine the influence of Na + presence in membrane degradation.…”

“…Some studies showed that the presence of Na + affects the intramembrane transport properties [ 26 , 27 ]. Madhav et al [ 26 ] used accelerated degradation via Fenton´s test to examine the influence of Na + presence in membrane degradation. They observed that the presence of NaCl accelerated the degradation of Nafion membranes in salty environments.…”

“…We checked if the swelling process of the investigated membranes obeyed a second-order kinetic and monitored the effect of the radiation on the dynamic swelling behavior. If we assume that the swelling process of the studied membranes follows a second order kinetic model, the swelling rate at any time t may be expressed as [ 19 ]: which can be linearized to obtain the Schott´s equation [ 26 ] …”

Effect of Mechanical Vibration on the Durability of Proton Exchange Membrane Fuel Cells

“…In order to ensure better forecast accuracy of the fuel cell's lifetime and analyze its probable degradation mechanism, the accelerated stress tests (ASTs) have been implemented by many researchers in experimental studies with regard to the contamination in hydrogen and air [4,5], start-up at subzero temperature [6][7][8][9] and dynamic response under driving cycles [10]. For the on-board fuel cells in vehicles, the performance degradation consists of membrane degradation, Pt/C catalyst degradation and gas diffusion layer degradation [11][12][13][14][15][16][17][18][19]. More specifically, the typical membrane degradation includes cracks, punctures and pinholes, resulting from a harsh operating environment accompanied by improper temperature, relative humidity and mechanical conditions.…”