The Influence of Iron Ions on Optical Brighteners and Their Application to Cotton Fabrics

Abstract

The influence of iron ions at concentrations of 0.2, 0.5, and 1.0 g/L on optical brighteners of the groups stilbene and biphenyl in solution and on cotton fabric was investigated. Both groups of optical brighteners are intended for detergent formulations. The influence of iron ions was studied by absorption and fluorescence spectra in solution and by whiteness degree, identifying color differences using CIEL*a*b* coordinates and Ultraviolet Protection Factor (UPF) of cotton fabrics. The obtained results in solutions and cotton fabrics showed different behavior of optical brighteners stilbene and biphenyl in the presence of iron. Stilbene compounds with metal ions produced new species capable of absorbing in the UV-B region of the spectrum. A biphenyl compound in combination with iron had no effect on the absorption properties. Both optical brighteners were influenced by iron ions in the sense of fluorescence quenching. The influence of iron ions in single- and two-bath treatments of cotton fabrics after one cycle on whiteness degree and UPF was negligible.

Luminescent transparent wood from a woody cellulosic template treated with an optical brightener

“…The enhancement of UV protection property as a result of OB treatment has been reported by several research works 53,54 . This mechanism of OB induced UV absorption was attributed to the generation of stilbene‐metal ion complexes during the treatment 55 . Previous studies have also correlated the optical properties of TW materials with the cellulose volume fraction and thickness of the material 9,10,56 .…”