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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.)

The Effect of Ormosil Matrix Composition and Alkaline Earth Metal Doping on the Photochromic Response of Ormosil-Phosphotungstate Films

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Ferreira Neto, Elias P. [1] ; Simoes, Mateus B. [1] ; Noveletto, Julia C. [2] ; Yabarrena, Jean M. S. C. [1] ; Ullah, Sajjad [3] ; Rodrigues Filho, Ubirajara P. [1]
Total Authors: 6
[1] Univ Sao Paulo, Inst Quim Sao Carlos, BR-13560970 Sao Carlos, SP - Brazil
[2] Univ Sao Paulo, Escola Engn Sao Carlos, Dept Engn Mat, BR-13560120 Sao Carlos, SP - Brazil
[3] Univ Peshawar, Inst Chem Sci, Peshawar 25120, KP - Pakistan
Total Affiliations: 3
Document type: Journal article
Source: Journal of the Brazilian Chemical Society; v. 26, n. 12, p. 2598-2606, DEC 2015.
Web of Science Citations: 1

In this study, polyoxometallate based hybrid photochromic materials were prepared by incorporating phosphotungstate anion, PW12O403-, (PW) in hybrid tetraethyl orthosilicate and (3-glycidyloxypropyl)trimethoxysilane TEOS-GPTMS derived organomodified silicates (Ormosil) matrices by sol-gel method and the resulting materials were used to prepare multilayer films by dip-coating method. The effect of alkaline earth metal cations doping and matrix composition (%GPTMS) on the photochromic response of the hybrid films was studied in details. GPTMS, after undergoing ring opening reaction, leads to the formation of chelating sites (diol and ether functionalities) which helps in anchoring of cations, which in turn interacts with phosphotungstate anions and favors their incorporation in the hybrid films. For a fixed concentration of GPTMS, the cation-phosphotungstate electrostatic interaction and hence the photochromic response of the films follow the order Mg2+ < Ca2+ < Sr2+ < Ba2+, thereby, indicating that larger cations interact more strongly with the heteropolyanions. The presence of these cations and GPTMS concomitantly leads to increased incorporation of phosphotungstic acid hydrate (HPW) in the films, resulting in a significant enhancement of the photochromic response. (AU)

FAPESP's process: 11/08120-0 - Nanostructured films: on the influence of the architecture on Photoactivity properties of films with phosphotungstate and nanoparticles
Grantee:Ubirajara Pereira Rodrigues Filho
Support type: Regular Research Grants
FAPESP's process: 13/24948-3 - CO2 fixation by SiO2@TiO2 nanoparticles decorated with Iron Ferrocyanide (Prussian Blue) and Ruthenium Ferrocyanide: toward high sustainability of biorefineries and ammonia synthesis plants
Grantee:Elias Paiva Ferreira Neto
Support type: Scholarships in Brazil - Doctorate