Luminescent Lanthanide(III)-containing Materials: Nanoparticles and Polymers
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Authors
Tigaa, Rodney Awelana
Issue Date
2017
Type
Dissertation
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Keywords
Lanthanides , Metallopolymers , Nanoparticles , Photoluminescence , Polymers , UV-Vis absorption , fluorescence and NIR spectroscopy
Alternative Title
Abstract
The unique luminescence properties of lanthanide(III) [LnIII] ions render them useful in applications such as imaging, sensing, security inks and telecommunications. Consequently, materials containing these ions continue to be extensively studied.The synthesis of II-VI semiconducting and fluorescent carbon nanoparticles (NPs) was achieved. The NPs were decorated with LnIII ions and successfully used as optical antennae to sensitize the metal-centered luminescence. Despite the metal-centered luminescence, the energy transfer from the NPs to the LnIII ions was inefficient, leading to low quantum yields of LnIII emission. However, we showed for the first time, through this work, energy transfer directly from a NP to surface-coordinated LnIII ions.Two new functionalized polycarbonate materials, one with a pyridine-2,6-bis(ethyl)ester (BEP) chromophore and the other with a pyridine-2,6-bis(diethylamide) (BDP) chromophore appended to a polycarbonate-backbone were synthesized. The materials were successfully used to chelate LnIII (Ln = Eu, Tb or Tm) ions and sensitize their luminescence. Emission efficiencies of 30% and 31% were measured for the EuIII and TbIII systems of BEP, respectively, while an emission efficiency of 2% was determined for both the EuIII and TbIII systems of BDP. In addition, the BEP polymer sensitized blue TmIII-centered emission. A blend of the polymers and their LnIII-containing systems were used to generate white-light.Finally, the BEP polymer was used to protect LnIII-doped ZnAl2O4 NPs from vibrational deactivation and as a sensitizer, leading to enhancement of the LnIII-centered emission.
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In Copyright(All Rights Reserved)