Avaliação de processos de degradação de corantes dispersos por técnicas eletroquímica e fotoeletroquímica usando eletrodos de Pt, filmes finos e nanotubos de 'TI'/'TIO IND. 2' e bicomponentes 'W'/'WO IND. 3'/'TIO IND. 2'

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Estudo da orientação dipolar fotoassistida de grupos azobenzênicos em filmes finos através de medidas da atividade eletro-óptica

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Photoelectrochemical Hydrogen Generation and Concomitant Organic Dye Oxidation under TiO2 Nanotube

The present work describes the photoelectrochemical hydrogen generation during a photodegradation of an organic compound. For this, it was chosen the reactive black 5 dye as a model of organic pollutant and its oxidation under TiO2 nanotube in a two compartment cell. The photoelectrocatalysis is conducted in 0.1 mol L-1 Na2SO4 pH 6 medium under photoanode biased at +1.0 V (SCE) and activated by UV and visible light using 150W Xe-Arc lamp (Oriel) and 125 W Hg lamp (Osram). The concomitant hydrogen production was monitored at cathodic compartment using a Pt cathode. Using optimized condition of Na2SO4 0.1 mol L-1 pH 6 as supporting electrolyte, applied potential of +1.0V it was verified 100% of discoloration and 72% of TOC removal of 1.0 x 10(-5) mol L-1 Reactive Black 5 dye after 120 min of treatment (rate constant of 10.6 x10(-2) min(-1)). The concomitant hydrogen generation was 44% in this condition.

A New and Simple Visual Technique Based on Indigo Dye for Determination of Ozone in Ambient Air

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Assessment of the breakdown products of solar/UV induced photolytic degradation of food dye tartrazine

The food dye tartrazine (CI 19140) was exposed to UV irradiation from an artificial source, a mercury vapor lamp, and a natural one, sunlight. It was observed that conditions such as energy dose, irradiation time, pH and initial dye concentration affected its discoloration. There was 100% of color removal, after 30 min of irradiation, when a dye solution 1 x 10(-5) mol L-1 was submitted to an energy dose of 37.8 J cm(-2). Liquid Chromatography coupled to Diode Array Detection and Mass Spectrometry confirmed the cleavage of the chromophore group and the formation of five by-products at low concentration. Although by-products were formed, the Salmonella/microsome mutagenicity assay performed for both, the dye solution at a dose of 5.34 mg/plate and the solutions obtained after exposure to UV irradiation, did not present mutagenic activity for TA98 and TA100 with and without S9. (C) 2014 Elsevier Ltd. All rights reserved.

Electrochemical investigations on the capacity of flavonoids to protect DNA against damage caused by textile disperse dyes

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Enhanced photoabsorption properties of composites of Ti/TiO2 nanotubes decorated by Sb2S3 and improvement of degradation of hair dye

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Highly Ordered TiO2 Nanotubes for Electrochemical Sensing of Hair Dye Basic Brown 17

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Identification of Sudan III-(deoxy)-guanosine adducts formed in situ in a reaction with no catalyst

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Impact of the Textile Dye Acid Blue 40 on the Periphyton of a Simulated Microecosystem

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação da toxicidade do azocorante Acid Red 114 antes e após processo de biodegradação por meio de um consórcio de microorganismos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Coherence characteristics of random lasing in a dye doped hybrid powder

The photon statistics of the random laser emission of a Rhodamine B doped di-ureasil hybrid powder is investigated to evaluate its degree of coherence above threshold. Although the random laser emission is a weighted average of spatially uncorrelated radiation emitted at different positions in the sample, a spatial coherence control was achieved due to an improved detection configuration based on spatial filtering. By using this experimental approach, which also allows for fine mode discrimination and timeresolved analysis of uncoupled modes from mode competition, an area not larger than the expected coherence size of the random laser is probed. Once the spectral and temporal behavior of nonoverlapping modes is characterized, an assessment of the photon-number probability distribution and the resulting second-order correlation coefficient as a function of time delay and wavelength was performed. The outcome of our single photon counting measurements revealed a high degree of temporal coherence at the time of maximum pump intensity and at wavelengths around the Rhodamine B gain maximum.

Removal of reactive dye from aqueous solution using thermally treated red mud

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The cosmetic dye quinoline yellow causes DNA damage in vitro

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)