Pigments extracted from the wood‐staining fungi Chlorociboria aeruginosa, Scytalidium cuboideum, and S. ganodermophthorum show potential for use as textile dyes

Abstract

A growing interest in the use of naturally produced pigments for textile dyeing has led to increased efforts towards the identification of such pigments that are less toxic, more sustainable, and more stable over time than currently used synthetic compounds. This work utilised various concentrations of green, red, and yellow pigments extracted with dichloromethane from the wood‐staining fungi Chlorociboria aeruginosa, Scytalidium cuboideum, and S. ganodermophthorum, respectively, for the effective dyeing of bleached cotton, spun polyamide (nylon 6.6), spun polyester (Dacron 54), spun polyacrylic, and worsted wool. All three pigments utilised in this study show significant potential for use as textile dyes. Colour changes suggested that drip application methods were superior to submersion using dichloromethane. Colour changes as compared with the untreated fabrics were most significant on polyester, which is likely due to increased levels of polymer swelling in polyester exposed to dichloromethane.

Mechanical Color Reading of Wood-Staining Fungal Pigment Textile Dyes: An Alternative Method for Determining Colorfastness

“…Only in the last couple of years has interest surfaced in using the extracted pigments from wood-staining fungi for the direct dyeing of textiles [2,3]. Application methods for depositing the pigments onto textiles has been researched [2], as have preliminary tests for colorfastness of these pigments using the drip method of application [3].…”

Wood-Rotting Fungal Pigments as Colorant Coatings on Oil-Based Textile Dyes

“…Previous textile tests with the aforementioned fungal pigments showed significant differences in pigment binding and uptake between application methods (dripping and submersion) [19]. A saturation test was performed to determine how saturated (how "dark") the textiles could become, to help determine the color range possible.…”

“…As the carrier is the differentiating factor, the difference may be due to the slow evaporation time of the oil. Previous tests [19,27] have shown that the colors on various substrates "build" in saturation with more coats applied, but only if the carrier from the previous application has completely dried. When using DCM, this process is quite fast and textiles either capable of holding more pigment, or upon which the pigment has a unique formation [18] (e.g., polyester), end up with a much higher amount of color change.…”

“…Although these fungal pigments can grow in water, organic solvents are needed in order to extract and apply the pigments. In addition, experimental data show that once bound to a substrate (e.g., a fabric) these pigments cannot be solubilized without harsh organic solvents [19,20] due to their insoluble nature in most solvents, including water. Although this low solubility characteristic lends the pigments good colorfastness for textile applications, it also presents challenges-in particular, for finding a non-toxic carrier for pigments in textile dyeing.…”

“…Although a few organic solvents (e.g., acetone, acetonitrile, and tetrahydrofuran) have been found that can carry a small amount of fungal pigments, there are issues with the color consistency and stability of the pigments in these solvents [19,20]. To date, dichloromethane (DCM) has been found to be the most effective solvent for the pigment extraction and as the carrier for textile coloration, and is the lowest toxicity solvent in which the pigments remain stable [20].…”