Surface functionalization of wool via microbial-transglutaminase and bentonite as bio-nano-mordant to achieve multi objective wool and improve dyeability with madder

Abstract

Recently, natural dyes have a widening scope in various traditional and advanced applications due to their eco-friendly environment. However, improved dyeability of natural dyes still remains a challenging task. This research was aimed to achieve multi-objective wool with improved dyeability using bio-nano-mordant composed of m-Trans-glutaminase, m-TGase, and bentonite nanoclay. Wool fiber was treated through sonochemical method using different concentrations of m-TGase and bentonite. The surface morphology of wool fabric samples was examined by field emission-scanning electron microscopy (FESEM), and Fourier transform Infrared Radiation (FTIR). Further, wool samples treated at different conditions were applied to madder for dyeability examination. The optimum conditions of color coordinates, color strength, K/S, and washing fastness of madder on treated wool fabric with m-TGase and bentonite, were also examined. The results revealed well-made interactions among m-TGase, bentonite, and wool fibers. In addition, surface morphology was strongly influenced by variations in enzyme concentrations so that extra addition of m-TGase lead to clear damage scales or less cuticle surface in SEM images. Moreover, the results showed that the value of K/S for treated wool samples was better than untreated samples. Indeed, amongst all, 5% concentrations of bio-nano-mordant for m-TGase and bentonite have the most constructive K/S values. Similarly, results of Δ E and antibacterial investigations also confirmed its superiority.

Chromatic and medicinal properties of six natural textile dyes: A review of eucalyptus, weld, madder, annatto, indigo and woad

“…Bentonite is a clay that is created by the weathering of volcanic ash. Both materials are considered good candidates for the textile industry because of their environmentally friendly properties [ 52 ].…”

“…No color change was observed after washing, demonstrating good K/S values. [ 52 ] Pour et al, 2020 The madder-dyed wool fabrics treated with bio-nano-mordant composed of microbial transglutaminase ( m -TGase) and bentonite showed highest K/S values and antibacterial activity for comparing with untreated. The treated samples resulted in a change in hue from pink to red and a lighter red hue was obtained with higher m -TGase concentrations.…”

“…Using primary colors of natural dyes provides an opportunity to obtain a broad spectrum of shades and expand the color palette of textiles dyed with natural colorants [ 24 ]. However, increasing the dyeability of natural dyes remains challenging [ 31 ]. The dyeability of natural dyes depends on various factors, such as the chemical structure and molecular weight of the dye molecules, the pH and temperature of the dyeing solution, the type and concentration of mordants and the type and structure of the textile fiber [ 32 ].…”

Bio-mordants: a review

“…In one study, madder was used as a natural dye, and alum and the transglutaminase (m-TGase) enzyme were used as mordants for dyeing wool fabric (Pour and He 2020a ). In another study, Pour et al ( 2020b ) used m-TGase and bentonite as bio-nano-mordants for dyeing wool. They modified the surface of the wool by adding the appropriate amount of m-TGase due to the cross-linking reaction between the two main amino acids of the wool, glutamine and lysine.…”

“…The inhomogeneous surface of the obtained hydrophilic wool interacted with the hydrophilic bentonite and thus provided a rough surface for the placement of dye molecules during the dyeing process. It was stated that the surface modification significantly affects the obtained color strength (Pour et al 2020b ). It is seen that some enzymes can be used in natural dyeing processes, but it would be more appropriate to classify them as auxiliary substances that can increase the color yield of textile materials rather than directly calling them mordants.…”