Elsevier

Dyes and Pigments

Volume 162, March 2019, Pages 222-231
Dyes and Pigments

Photo-stability of a flavonoid dye in presence of aluminium ions

https://doi.org/10.1016/j.dyepig.2018.10.021Get rights and content
Under a Creative Commons license
open access

Highlights

  • Photo-stability of luteolin decreases with increasing concentrations of Al ions

  • Light-fastness of colour of weld-dyed wool also decreases with increasing [Al3+]

  • The lower the [Al3+] used for mordanting the wool, the more light-fast its colour

  • Using low [Al3+] limits the obtainable yellow colours

  • This approach could be of technical, environmental and financial benefit

Abstract

The main colouring compounds of the dye plant weld (Reseda luteola L.) are the flavones luteolin (lut), lut-7-O-glucoside and lut-7,3ʹ-O-diglucoside. Alum (an aluminium salt)-premordanted wool dyed with weld leads to yellow colours that are of low resistance to light. The photo-stability of lut in aerated methanol–water 8:2 (v/v) solution upon irradiation with light above 300 nm was studied at different lut–Al3+ ratios. Experiments using extracts of weld to dye wool premordanted with increasing quantities of aluminium salts were also carried out. The photo-stability of lut in the polar protic solvent and the photo-resistance (light-fastness) of the colour of weld-dyed wool decrease with increasing concentrations of aluminium ions. Thus, the lower the [Al3+] used for mordanting the wool, the more light-fast its colour. Lowering the [Al3+] appears to have no negative influence on the wash-fastness of the colour. As the gain in light-fastness by the use of low [Al3+] to premordant the wool is not extensive, however, this does not seem to be a way to meet today's requirement of light-fastness of the colours of dyed textiles by itself. Nevertheless, it may be part of a bigger strategy to address the need for increased light-fastness of the colour of wool dyed with weld. Implementation of this approach by dyers is expected to clarify whether it results in benefits for textile dyeing practice.

Keywords

Weld
Reseda luteola
Flavonoid
Luteolin
Natural dye
Light-fastness

Cited by (0)

1

Current affiliation: Avans University of Applied Sciences, Research Group Biobased Products, P.O. Box 90.116, 4800 RA Breda, The Netherlands.