Immobilization of ²-diketones on organo modified kaolinite with alkoxides: possibl...
| Full text | |
| Author(s): |
de Araujo, Denis Talarico
;
Ciuffi, Katia J.
;
Nassar, Eduardo J.
;
Vicente, Miguel A.
;
Trujillano, Raquel
;
Calefi, Paulo S.
;
Rives, Vicente
;
de Faria, Emerson H.
Total Authors: 8
|
| Document type: | Journal article |
| Source: | Journal of Physical Chemistry C; v. 121, n. 9, p. 5081-5088, MAR 9 2017. |
| Web of Science Citations: | 3 |
| Abstract | |
The luminescence properties of Eu3+- and Tb3+-dipicolinate (pyridine- dicarboxylate) complexes covalently grafted into a kaolinite matrix were studied. The stability of the grafted lanthanide complexes as a function of the thermal treatment was also investigated. Kaolinite intercalated with dimethyl sulfoxide was heated in the presence of melted dipicolinic acid to form dipicolinate-intercalated kaolinite. The luminescent hybrid solids were obtained by complexation of Eu3+ or Tb3+ cations with this intercalated solid at cation/ligand molar ratios of 1:1, 1:2, or 1:3. The resulting materials were characterized by thermal analysis, CHN element analysis, powder X-ray diffraction, infrared absorption spectroscopy, and photoluminescence. The lanthanide complexes covalently grafted into kaolinite were thermally more stable than the isolated lanthanide complexes. The hybrid materials exhibited more intense Eu3+ and Tb3+ emissions than the isolated complexes. The excitation spectra of the hybrid materials showed a broad band at 277 nm, assigned to a ligand-to-metal charge transfer, whereas the emission spectra showed bands related to the typical electronic transitions of Eu3+ and Tb3+ ions from the excited states D-5(0) and D-5(4) to the F-7(j) fundamental states. The (4 -> 5 and 4 -> 4) and (0 -> 2) transitions were the most intense ones and corresponded to green and red emissions, respectively. (AU) | |
| FAPESP's process: | 13/19523-3 - Functional Biohybrid materials based on layered and/or fibrous natural clays with multifaceted applications |
| Grantee: | Emerson Henrique de Faria |
| Support type: | Regular Research Grants |
| FAPESP's process: | 16/01501-1 - Multifunctional catalysts for advanced oxidation processes employing biogenic matrices or clays |
| Grantee: | Katia Jorge Ciuffi Pires |
| Support type: | Regular Research Grants |
| FAPESP's process: | 13/50216-0 - New clay-based materials with advanced technological and environmental applications |
| Grantee: | Katia Jorge Ciuffi Pires |
| Support type: | Regular Research Grants |