Ion exchange and luminescence of Eu3+ in Nafion membranes

Dehydration of Nafion perfluorosulphonic membranes at 110 °C results in a significant reduction of their void space volume, the accessibility of sulphonic groups and the total exchange capacity towards Eu3+ cations. Nevertheless, the ion exchange sorption of Eu3+ takes place in accordance with stoichiometric ratio [-SO3H]/[Eu3+]=3. The membranes thermal pretreatment also affects noticeably the spectroscopic features of the fastened Eu3+ ions, such as the relationship between the intensities of the hypersensitive 5D0→7F2 and magnetic dipolar 5D0→7F1 transitions, the excited state life time, as well as the luminescence quenching in the course of water adsorption.