| Full text | |
| Author(s): |
Molina, Eduardo F.
[1]
;
Parreira, Renato L. T.
[1]
;
De Faria, Emerson H.
[1]
;
de Carvalho, Hudson W. Pereira
[2]
;
Caramori, Giovanni F.
[3]
;
Coimbra, Daniel F.
[3]
;
Nassar, Eduardo J.
[1]
;
Ciuffi, Katia J.
[1]
Total Authors: 8
|
| Affiliation: | [1] Univ Franca, BR-14404600 Franca, SP - Brazil
[2] KIT, D-76131 Karlsruhe - Germany
[3] Univ Fed Santa Catarina, Dept Quim, BR-88040900 Florianopolis, SC - Brazil
Total Affiliations: 3
|
| Document type: | Journal article |
| Source: | Langmuir; v. 30, n. 13, p. 3857-3868, APR 8 2014. |
| Web of Science Citations: | 29 |
| Abstract | |
Herein, we present a cross-linked ureasil-polyether-siloxane hybrid (labeled PEO500) that can function as a stimuli-sensitive material; it swells or shrinks in response to changes in the environmental conditions and it can also, effectively and selectively, remove dyes from water solution. We also developed a methodology to separate a mixture of cationic and anionic dyes present in water. Addition of PEO500 to an aqueous solution of the anionic orange II (OII) or the ponceau S (PS) dye rendered the solution colorless, but an aqueous solution of cationic methylene blue (MB) remained unchanged after 2 h of contact with the insoluble matrix. In situ small-angle X-ray scattering (SAXS) showed that the distance of siloxane nanodomains are strongly affected by the swelling or shriking. By in situ UV-vis adsorption experiments, we found that the kinetics of OII and PS removal followed a pseudo-first-order rate equation. We accomplished B3LYP calculations, to establish which sites on the matrix interacted with the dyes and to investigate the nature of the matrix-dye chemical bonds. On the basis of the experimental and theoretical investigations, we proposed some mechanisms to explain how PEO500 adsorbs anionic dyes efficiently. This ``smart{''} matrix is potentially applicable as an efficient, fast, selective, and convenient device in water treatment and stimuli-sensitive response materials. (AU) | |
| FAPESP's process: | 12/05514-0 - Development of new adsorbents for the removal of reactive species and heavy metal-based organic-inorganic hybrids |
| Grantee: | Eduardo Ferreira Molina |
| Support Opportunities: | Scholarships in Brazil - Post-Doctoral |