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| Author(s): |
Fernanda Cesar dos Santos
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Araraquara. 2017-05-08. |
| Institution: | Universidade Estadual Paulista (Unesp). Instituto de Química. Araraquara |
| Defense date: | 2017-03-27 |
| Advisor: | Marian Rosaly Davolos |
| Abstract | |
Luminescent materials based on lanthanide ions have many technological applications, such as in light emitting or molecular optical devices, resulting in an interest in the searching and in the deep study of these materials, especially in studies of their conformation control. In this work, it was studied the structural and spectroscopic properties of europium betradetonate complexes when conformed in bulk solid and in Langmuir and Langmuir-Blodgett mixed films of the neutral complex and the surfactant. The experimental techniques applied were luminescence spectroscopy by UV-Vis and X-rays excitation, especially the in situ luminescence spectroscopy by UV-Vis excitation during the formation of the Langmuir films. For the study of the films, were obtained isotherms of surface pressure versus molecular area of mixed complex in the presence of stearic acid or in the presence of dimethyldioctadecylammonium bromide (DODA), stability curves, reversibility curves of the mixed films on the aqueous surface beyond the deposition of such films to a glassy substrate, besides the monitoring of Langmuir film formation by Brewster Angle Microscopy (BAM). The stability and reversibility measures indicated the formation of possible agglomerates of the mixed films using stearic acid as a spacer, whereas the mixed films in the presence of DODA showed to be more stable on the aqueous surface. The BAM images revealed that DODA works effectively in the process of film homogeneity of the europium complexes and in situ luminescence measurements have shown the dependence of the emission intensity on the homogeneity of the film. Langmuir-Blodgett films of the mixed complex / spacer system showed the prevalence of cohesive forces over the adhesive forces of the species on the aqueous surface. This study showed how attached the molecular organization of the material with the luminescence. (AU) | |
| FAPESP's process: | 15/12630-4 - Luminescence in situ measurements to study Langmuir and Langmuir-Blodgett films of europium coordination compounds |
| Grantee: | Fernanda Cesar dos Santos |
| Support Opportunities: | Scholarships in Brazil - Master |