Confocal Raman micro-spectroscopy and electrochemical investigation of anion transport through ion-exchange membranes

The aim of this study is the determination of the ionic distribution versus the spatial coordinates within the membrane polymers. The confocal Raman spectroscopy is a useful tool for the study because it allows investigation of the species nature within materials. The studied membrane is a AW from Solvay (with a poly-4-vinylpyridine graft and an ethylene tetrafluoroethylene matrix). The first results are the pK value (2.25), verification of the graft’s homogeneity in the whole membrane and an initial study about ionic transport within membrane and spectra analysis with factor analysis (principal components analysis and evolving factor analysis with multivariate curve resolution).

In conclusion, the different study of the membrane are conclusive and allows to continue the determination of the ionic distribution inside the polymer film and the study of the ionic transport. The next step is the application of an electric field in the different compartments of the transport cell. Moreover, the factor analysis method (PCA, EFA and MCR) is a powerful method to examine Raman spectra and obtains different informations about the ionic transport process through the AW membrane.