Insights on Structuration of Peroxotungstic Acid in Aqueous Media

Autor(es)

Pazinato, Julia C. O. ^[1] ; Villetti, Marcos A. ^[2] ; Mertins, Omar ^[3] ; Silva, Emerson R. ^[3] ; Garcia, Irene T. S. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed Rio Grande do Sul, Dept Fisicoquim, Inst Quim, BR-91501970 Porto Alegre, RS - Brazil

^[2] Univ Fed Santa Maria, Ctr Ciencias Nat & Exatas, Dept Fis, BR-97105900 Santa Maria, RS - Brazil

^[3] Univ Fed Sao Paulo, Escola Paulista Med, Dept Biofis, BR-04023062 Sao Paulo, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of the Brazilian Chemical Society; v. 30, n. 4, p. 752-763, APR 2019.
• Citações Web of Science: 0

Resumo

Recent studies on tungsten oxide preparation are mainly motivated by its applications in smart windows, energy harvesting and, recently, in cancer therapy. Peroxotungstic acid (PTA) is an important precursor to obtain tungsten oxide in an environmentally-friendly way, through the colloidal synthesis in aqueous media. Despite giving chemically pure products, PTA originates oxides with various morphologies depending on the experimental conditions, a subject open to discussion. PTA, in the presence of sodium dodecyl sulfate (SDS) as architecture-directing agent, was investigated in ethanol/water medium by small angle X-ray scattering (SAXS), fluorescence, surface tension and conductivity measurements; the morphology of tungsten oxide obtained from the precursor systems was also characterized by scanning electron microscopy (SEM). PTA/SDS/ethanol/water systems show a two-level organization in which small micelles are aggregated as fractal structures. There is an inverse correlation between gyration radius of the fractal structures of the PTA/SDS systems and particle size of the tungsten oxide films. The interaction of PTA with SDS is observed by reducing the Gibbs energy of micellization; also, it is evidenced that the supressive effect of PTA on pyrene emission is overrided in presence of SDS. (AU)

• Processo FAPESP: 15/23948-5 - Aperfeiçoamento das propriedades do polissacarídeo quitosana para aplicação em lipossomas e vesículas gigantes
• Beneficiário: Omar Mertins
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 16/24409-3 - Peptídeos Penetrantes de Células para Transporte de DNA plasmídial e microRNA: da Estrutura Nanoscópica a Entrega de Genes.
• Beneficiário: Emerson Rodrigo da Silva
• Modalidade de apoio: Auxílio à Pesquisa - Regular