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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Ureasil-Poly(ethylene oxide) Hybrid Matrix for Selective Adsorption and Separation of Dyes from Water

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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
[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

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 type: Scholarships in Brazil - Post-Doctorate