From Textile Coloring to Light-emitting Electrochemical Devices: Upcycling of the Isoviolanthrone Vat Dye

Produced at ton scale, vat dyes are major environmental pollutants generated by the textile industry. However, they represent ideal and accessible candidates for chemical upcycling since they are usually composed of large π-conjugated scaffolds. Based on the valorization of "old" products, waste or even contaminant into high-added value goods, this concept can be easily transposed to the laboratories. As a contribution to the current environmental and ecological transition, we demonstrate herein the valorization/upcycling of wastewaters generated during the dyeing procedure. To do so, the reduced (leuco) form of vat violet 10, also known as isoviolanthrone, was functionalized to afford a readily soluble derivative that was subsequently and successfully used as active material in operating solution processed light-emitting electrochemical cells, that is, from textile dyeing to high-tech application.

Direct electrochemical capture and release of carbon dioxide using an industrial organic pigment: quinacridone

Limiting anthropogenic carbon dioxide emissions constitutes a major issue faced by scientists today. Herein we report an efficient way of controlled capture and release of carbon dioxide using nature inspired, cheap, abundant and non-toxic, industrial pigment namely, quinacridone. An electrochemically reduced electrode consisting of a quinacridone thin film (ca. 100 nm thick) on an ITO support forms a quinacridone carbonate salt. The captured CO2 can be released by electrochemical oxidation. The amount of captured CO2 was quantified by FT-IR. The uptake value for electrochemical release process was 4.61 mmol g(-1). This value is among the highest reported uptake efficiencies for electrochemical CO2 capture. For comparison, the state-of-the-art aqueous amine industrial capture process has an uptake efficiency of ca. 8 mmol g(-1).

Biochemical parameters of liver function in artisans occupationally exposed to "vat dyes"

BACKGROUND

Vat dyes are the class of dyes used in textile dyeing in Abeokuta, South Western Nigeria. While some dyes (including vat dyes intermediates) have been associated with adverse effects on manufacturer's health, there is paucity of data on effects of occupational exposure to vat dyes among end users, such as those involved in textile dyeing and finishing.

AIMS AND OBJECTIVES

To investigate the possible effect of occupational exposure to vat dyes on the functions of the liver.

MATERIALS AND METHODS

Using convenience sampling technique, a cohort of dye workers (n=117) with a minimum of one year and a maximum of 60 years duration of exposure (mean =17.03 ± 1.19 years) were recruited in this study. Sixty traders, matched for age and sex and who had no previous exposure to vat dyes were selected as controls. A structured questionnaire was used to obtain information on demographic, occupational and environmental characteristics of the subjects. Plasma activities of alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP) and plasma concentrations of total protein, albumin and total bilirubin were measured using standard spectrophotometric methods.

STATISTICAL ANALYSES

SPSS version 11.0 was used for statistical analyses. Tests of significance were carried out using Student's t test, and correlation co-efficient.

RESULTS AND CONCLUSION

The activity of ALP and the concentrations of total protein and albumin were significantly lower (P <0.05) in the exposed group. ALT and AST activities were significantly higher (P <0.05) in the exposed group. Occupational exposure to vat dyes may result in sub-clinical adverse effects on the liver, involving inhibition of its synthetic function.