Fluorimetry and differential scanning calorimetry have been used to characterize ionomers that were synthesized by copolymerization of methyl methacrylate, methacrylic acid, and europium methacrylate (EMA). Under excitation of UV light at 375 nm no self-quenching was found in fluorescence of EMA-containing ionomers at 615 nm within the Eu3+ concentration range of 1.6 x 10(-2) to 11.49 x 10(-2) mol %, which means that the distance between two Eu3+ ions is larger than 50 Angstrom. In the same concentration range self-quenching took place in europium octanoate (EOA)-containing ionomers in which EOA was doped as an additive. Only one T-g was found for both binds of polymers within the concentration range of Eu3+ ions. For all ion contents studied, T-g values were essentially independent of ion content and values were slightly higher for the EMA containing ionomers.