Extraction of natural dyes from the stem of Caulis spatholobi and their application on wool

Abstract

Researchers are continuously exploring new candidates in the field of natural dyeing to lighten the burden of synthetic dyestuff on living organisms. In this research, novel natural dye was explored using the Caulis spatholobi plant. The extraction was carried out through the conventional extraction method in the aqueous medium. Various parameters of the natural dye extraction process, such as the material-to-liquor ratio, pH, time and temperature, were optimized to 1:40, 12, 120 min and 100℃, respectively. The extract was filtered twice and used for the characterization and dyeing of wool fabric. The extract was characterized using Fourier transform infrared spectroscopy for the determination of dominant functional groups. Natural dyeing of wool was carried out with and without metal mordants, such as aluminum sulfate, ferrous sulfate, copper sulfate and zinc sulfate. Pre-mordanting, meta-mordanting and post-mordanting techniques were employed. The performances of dyed fabrics were evaluated in terms of color strength K/ S values. The fastness properties of dyed fabrics were also measured. The dyed fabric showed various color shades based on the type of mordant used. Furthermore, enhancement in the colorfastness was observed with mordanting.

Dyeing mechanism and photodegradation kinetics of gardenia yellow natural colorant

“…The curves increase sharply at the beginning of dyeing owing to the rapid fixation of dye molecules on the fabric with the help of mordant metal ions (Al 3+ ) which form complex bonds simultaneously with the dye molecules and fibers, as represented in Figure 7. 49 In this way the dye was rapidly fixed to the surface of fibers resulting in a sharp increase in dye uptake, and after 90 min the dyeing rate curve started flattening and the dyeing process tended to balance. The temperature had a significant impact on the gardenia yellow dyeing of the cotton fabric; that is the higher temperature led to more dye uptake.…”

Review on Extraction and Application of Natural Dyes

“…But the extraction process is affected by pH, time, temperature and liquor ratio. So, for better dyeing performance and K/S, these variables have to be optimized [70]. Silk can be dyed using the exhaust dyeing method with dye extracted from Alpinia blepharocalyx K. Schum.…”

Eco-friendly isolation of tannin based natural colorant from coconut coir (Cocos nucifera) for dyeing of bio-mordanted wool fabric

“…This is because wool fabric containing amido linkage force protontion under acidic conditions (pH < 3), due to which active sites are available for bonding (Jiang et al, 2019). Whereas due to higher pH (pH >3), the certain sites are not available to give good color depth (Rani et al, 2020).…”