The Spectral Properties Of Polyamide Polymer Doped With Rare Earth Ions

Investigations pertaining to the polymer materials containing rare earth ions have intensified in recent years, mainly due to the potential of these widely useful materials for light-emitting devices, high magnetic materials etc. Moreover, polyamide polymers are also acquired a great importance for their wide applications in biomedical materials, pharmaceutical fields and analytical chemistry. However, researches concerning polyamide materials containing rare earth elements have not been reported until recently.In this paper, several series of binary and ternary polyamide complexes containing rare earth ions were synthesized for the first time by blending three polyamide polymers (poly N-vinylacetamide, poly N-vinylisobutyramide and poly N-isopropylacrylamide), four rare earth elements (Samarium, Europium, Terbium and Dysprosium) and two low molecular weight ligands (thenoyltrifluoroacetone, triphenylphosphineoxide) respectively. My researching focus was judging the formation of those complexes, developing conditions of doped rare earth ions, measuring spectral properties and luminescence behaviors of those materials by means of ultraviolet spectroscopy, Fourier transform infrared transmission spectroscopy, X-ray photoelectron spectroscopy and fluorescence spectroscopy and finally on theoretical analysis of experimental results. Their potential uses as novel luminescent materials were also discussed.The experimental results of UV, IR and XPS suggested that there exist at least two actions between the polyamide macromolecules and rare earth ions in these complexes. One is coordination action and another is electrostatic force. Although they are quite different in terms of intrinsic characters, both of them could change the conformation and conjugated structure of these polymers and further influence the properties of absorption and emission.The fluorescence emission spectra of terbium binary and ternary complexes show intensive characteristic emissions of terbium ions, indicating that there exists effective energy transfer behavior between terbium ion and polymer ligands. However, other binary complexes display merely emission bands of polymeric ligands, indicating that the energy levels of triplet state of polymer ligands do not match the excited states of other rare earth ions. In ternary complexes, the characteristic emission intensities of rare earth ions were greatly increased by the introduction of low molecular weight ligands as a result of synergetic effect between them. Especially, Eu (III)-TTA-PNVA and Eu (III)-TTA-PNVIBA are potential luminescent materials in respect that not only they could emit intensive monochromatic red light at 617 nm excited by UV light at 380 nm, but also they have stable chemical characters.