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

Autor(es)

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]

Afiliação do(s) autor(es)

^[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

• Tipo de documento: Artigo Científico
• Fonte: Journal of the Brazilian Chemical Society; v. 26, n. 12, p. 2598-2606, DEC 2015.
• Citações Web of Science: 1

Resumo

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)

• Processo FAPESP: 13/24948-3 - Fixação de CO2 por Nanoparticulas de SiO2@TiO2 decoradas com Ferrocianeto de Ferro (Azul da Prússia) e Ferrocianeto de Rutênio: Uma Possível Alternativa para o aumento de Sustentabilidade de Biorefinarias e Plantas de Síntese de Amônia
• Beneficiário: Elias Paiva Ferreira Neto
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 11/08120-0 - Filmes nanoestruturados: impacto da arquitetura dos filmes contendo nanopartículas e fosfotungstato sobre as propriedades fotoativas
• Beneficiário: Ubirajara Pereira Rodrigues Filho
• Modalidade de apoio: Auxílio à Pesquisa - Regular