Comparison between the optical properties of cotton and wool fabrics dyed with a natural dye using different mordents

摘要

Cotton and wool fabrics were dyed by Calligonum Comosum extracted from the barks of the plant. The dyed cotton and wool fabrics were mordanted by different mordants that are: Alum (potassium aluminum sulfate), ferrous chloride and ferrous sulfate which were applied separately. The effect of different mordants on the reflectance spectra was investigated using spectrophotometer tool and CIE tristimulus values. The color parameters including L, a, b, h, c and AE were determined. A comparison between the effect of mordanting on both the cotton and wool fabrics by the same three mordants was done. The data obtained indicated that the optical properties are totally different as a result of the nature of wool which is a protein fabric and cotton which is a cellulosic fabric. The different mordants gave different colors and shades which encourage the use of natural dyes instead of synthesis dyes; also, the absorption coefficient (a) was calculated in the visible range. The decrease in transmission and increase in absorption coefficient with the change in the mordant type may be due to the change in the molecular configuration as a result of the change in the chemical bonds in the fabric, dye and the mordant. The optical studies can differentiate between different kinds of fabrics with different kinds of mordants present in small proportions.