RESUMO
The functionalization of cotton fabric with photoactive TiO2-Ag-AgBr nanostructured layer has been successfully developed using a low temperature non-aqueous sol-gel route and aqueous suspension of AgBr. Evidence for the growth of TiO2 layer and the immobilization of AgBr nanoparticles have been confirmed by Raman, XRD and XPS. GSDR analysis revealed a strong absorption in the visible region brought by surface Plasmon resonance (SPR) of Ag nanocrystals generated at the surface of AgBr. The XPS evidenced the presence of Ag+, Ag0 and bromine, suggesting that Ag0 formed a shell around the deposited AgBr. The immobilized TiO2-Ag-AgBr heterostructured layer imparts a strong photocatalytic activity under visible light for the degradation of dyes in aqueous solution as well as of dimethyl methylphosphonate (DMMP), a chemical warfare agent simulant. These new catalytically active functionalized fabrics, with self-detoxification properties, have great potential for application in chemical protective clothes and might offer new opportunities for the design of functional materials for toxic chemical protection.
Assuntos
Brometos/química , Corantes/química , Fibra de Algodão , Organofosfatos/química , Processos Fotoquímicos , Compostos de Prata/química , Prata/química , Titânio/química , Catálise , Corantes/isolamento & purificação , Nanoestruturas/química , Organofosfatos/isolamento & purificação , Organofosfatos/toxicidade , Temperatura , Água/química , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação , Purificação da ÁguaRESUMO
Avaliou-se o efeito do bissulfato de sódio, aplicado sobre a cama de frangos, criados em diferentes densidades, na sobrevivência de Escherichia coli e coliformes, utilizando-se as densidades de 12, 16 e 20 aves/m², com a inoculação de uma cepa de E. coli. Houve maior desenvolvimento microbiano no 21° dia de criação, com tendência de redução a partir daí. A eficácia do bissulfato de sódio foi maior nos primeiros dias do experimento.
The effect of sodium bisulfate has been evaluated on survival of Escherichia coli and coliforms, when applied on the broiler beds, adopting different densities. It has been adopted densities of 12, 16 and 20 birds/m², using inoculations of E. coli strains. The results have shown the highest microbial development on the 21st day of inoculation, with a trend of a microbial reduction afterwards. The sodium bisulfate was efficient during the first days of analyses, reducing its efficacy during the experiment.
