Development of extraction and application of alizarin from madder roots using supercritical carbon dioxide and its sustainable application on textile

Abstract

Low temperature, extraction pressure, critical carbon dioxide are the most commonly used supercritical condition. Super critical carbon dioxide was used to extract alizarin from madder roots (Rubia tinctorum) under various conditions, including temperature of 30–60 °C, pressure of 50–250 bar, extraction duration of 20–80 min, and flow rate of 5–9 mL/min. Under ideal circumstances, alizarin discovery in R. tinctorum extract (RE) of 1.34 g/kg roots with the concentration of 6.42 %. Wool textiles were dyed at various concentrations, pH levels, and times using microwave dyeing techniques.  Low molecular weight chitosan was substituted for mordent at varying doses of 2–10 g/L. For both treated and untreated fibers, fastness characteristics of colored wool textiles were investigated. The dyeing characteristics and the fastness property were improved by the mordent. Technology was used to extract pigment of alizarin from R. tinctorum as a sustainable substitute for traditional extraction techniques.  The impact of chemical, natural mordents, and extract concentration on the coloring characteristics of dyed wool textiles were assessed.  Additionally, the antibacterial qualities of the dyed wool fabrics against bacteria and yeast including Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus epidermidis, and Candida albicans were assessed.