Ecological Dyeing of Cotton with Reactive Dyes in Sea Water

Abstract

Using sea water as a textile dyeing medium is an innovative and environmentally friendly approach that addresses the challenges associated with conventional fresh water dyeing methods. Dyes with one functional group were used in the work: Remazol red B and Ostazin blue H-BR. The reflectance of the samples was measured at wavelengths 400-700 nm and the CIELab color coordinates were determined. Based on the reflection value at the wavelength of maximum adsorption for each sample the color intensity (K/S) was calculated according to the Kubelka-Munk equation. Color lightness L* is the vertical coordinate of the three-dimensional CIELab system and shows the similarity of chromatic color to achromatic colors. The higher the value of L*, the more similar a chromatic color is to white - achromatic color. For both reactive dyes used, the highest lightness is achieved by samples dyed with real sea water without NaCl, and the difference in lightness is greater on samples dyed in a darker shade. The color intensities of the samples dyed with 1% Remazol red B in sea water have minimally changed in relation to the intensity of the reference sample dyed in distilled water. Fabric dyed in simulated and real sea water with 50% less NaCl concentration has a minimally higher color intensity compared to the sample dyed in distilled water. Dyeing with 3% reactive dye Ostazin blue H-BR in sea water results in reduced color intensity, which is more pronounced than dyeing with 1% dye. In the case of a system with real sea water the reduction in intensity is about 12%. Based on the results obtained by reflection spectrophotometry, it can be concluded that it is possible to dye cotton fabric with selected monofunctional reactive dyes in light shades with half the amount of NaCl compared to standard dyeing.