Physical dispersion state and fluorescent property of Eu-complex in the Eu-complex/silicon rubber composites

The fluorescent complex Eu(TTA)2(Phen)(MA) (HTTA=2-Thenoyltrifluoroacetone, Phen=1,10-phenanthroline, MA=Maleic anhydrider) was synthesized and characterized with elemental analysis, infrared spectrum (IR), scanning electron microscope (SEM), X-ray Diffraction(XRD), differential scanning calorimetry(DSC), and fluorescent measurement. To explore the effect of different physical dispersion state of Eu-complex on the fluorescent property of the Eu-complex/silicon rubber composites, various quantities of Eu(TTA)2(phen) (MA) were mixed with silicon rubber (SiR) and peroxide to form uncured composites. These composites were vulcanized to obtain cured Eu-complex/SiR composites at 250 °C, which was higher than the melting-point of Eu-complex. The SEM, XRD, DSC, and the fluorescent measurement of these composites showed that both the complex molecules dispersed in the silicon rubber during the melting process and the parent Eu-complex particles had positive effects on fluorescent property, whereas the re-crystallized Eu-complex particles and the aggregating complexes formed during the melting-process had negative effects on fluorescent property. For the uncured composites, their fluorescent intensities almost did not change with the increasing amount of Eu-complex. Furthermore, for the composites with small content of Eu-complex, their fluorescent intensities decreased significantly after curing, and this difference in fluorescent intensity became smaller as the content of Eu-complex increases.