Encontrados 20 documentos, a visualizar página 1 de 2
Polyaniline coated conducting fabrics : chemical and electrochemical character...
Esteves, M. de Fátima; Molina, J.; Fernandéz, J.; Bonastre, J.; Cases, F.Polyaniline coated conducting fabrics have been obtained by chemical oxidation of aniline by potassium peroxydisulfate on polyester fabrics. Two different acids have been employed to carry out the synthesis (HCl and H2SO4), obtaining the best results of conductivity with the latter one. The conducting fabrics have been characterized chemically by means of Fourier transform infrared spectroscopy with attenuated ...
C.I. Reactive Black 5 degradation by advanced electrochemical oxidation process...
Esteves, M. de Fátima; Sousa, ElisabeteIn the last decades, an increasing number of procedures to remove pollutants from wastewater have been reported. Advanced oxidation processes (AOPs) are one of those technologies used for this purpose, namely, for textile wastewater treatment. AOPs are environmentally friendly methods based on chemical, photochemical or photocatalytical production of hydroxyl radical (HO•). This strong oxidant can react with mo...
CO2 laser modification on synthetic fibres:effect on dyeing properties
Esteves, M. de Fátima; Alonso, HelenaInfrared lasers, like CO2, appear to be advantageous due to their large beam size, high efficiency, easy operation, use of non-toxic gases and low cost. However, they have been less used than others for the surface treatment of polymers, likely due to the thermal damage effects caused by infrared radiation. This shortcoming can be overcome by use of pulsed lasers. CO2 pulsed laser can be considered as a non-con...
Effect of CO2 laser radiation on surface properties of synthetic fibres
Esteves, M. de Fátima; Alonso, HelenaChemical treatment methods are most often used in the present for polymer surface modification; however, these methods are frequently “environmentally unfriendly”. So, new technologies are now considered, especially in physical treatment methods. This is the case of laser technologies, like CO2 laser radiation. Morphological modifications can be produced on the surface of polymers, resulting in changes in the p...
Electrochemical degradation of C.I. reactive orange 16 in the presence of H2O2/...
Esteves, M. de Fátima; Sousa, ElisabeteThe aim of the present study was to investigate the electrochemical degradation of a vinylsulphone reactive dye, C.I. Reactive Orange 16, in the presence of hydrogen peroxide and copper ions. The reaction between these two species leads to the generation of hydroxyl radicals, causing dye oxidation and degradation. The efficiency of dyebath decolorization and dye degradation was evaluated by color removal and CO...
Voltammetric study and electrochemical degradation of reactive dyes
Esteves, M. de Fátima; Cunha, Elisabete P.The aim of this study was, in a first stage, to investigate the voltammetric behavior of two reactive dyes, C.I.Reactive Orange 16 and C.I.Reactive Blue 19. Cyclic voltammetry technique (CV), on a glassy carbon electrode, was used for this purpose in order to identify the electrochemical activity of the chromophore group in each case, in the present experimental conditions. A second part of the study was to inv...
Electrochemical degradation of reactive blue 19 dye in textile wastewater
Esteves, M. de Fátima; Silva, J. DinisTextile wastewater is notoriously known to contain strong colour, a highly fluctuating pH and significant COD (Chemical Oxygen Demand) values. Because of these characteristics, treatment of these effluents has been rather difficult. Traditional methods for dealing with textile wastewater consist of various combinations of biological, physical and chemical methods. Because of the large variability of the composi...
Optical brighteners effect on white and coloured textiles
Esteves, M. de Fátima; Noronha, A. Cyrne; Marinho, R. MarquesOptical brighteners are colourless to weakly coloured organic compounds that, in solution or applied to a substrate, absorb ultraviolet light and re-emit most of the absorbed energy as blue-violet light between 400 and 500 nm. These compounds are included in commercial detergents formulation in order to increase whiteness and intensifying the colours. The aim of this work was to study several industrial situati...
Comparative study on pilling resistence standard methods
Esteves, M. de Fátima; Fonte, A. P.; Fernandes, Francisco José MatosTextile fabrics are prone to develop balls of fibre on the surface, which are known as pills. The pills are formed during wear and washing, when fibres on the fabric surface “tease out” and become entangled. Under the influence of the rubbing action these loose fibres develop into small spherical bundles anchored to the fabric by a few unbroken fibres. Such a surface deterioration is generally undesirable, but ...
Descoloração de efluentes de tinturaria por oxidação electroquímica
Esteves, M. de FátimaOs efluentes provenientes da indústria tê xtil apresentam, de um modo geral, forte coloração, pH altamente variável e elevado teor em matérias oxidáveis, traduzido pelos significativos valores de C.Q.O. (Carência Química em Oxigénio). Devido a estas características e à variável composição destes efluentes, o seu tratamento através de métodos mais tradicionais (combinação de processos físicos, químicos e biológ...
| Financiadores do RCAAP | |||||||
|
|
|
|
|
|
||