Horseradish peroxidase-catalysed coloration of silk and cotton fabrics with phenols

Abstract

Enzymatic dyeing is an environmentally friendly and energy-efficient dyeing method conducted at low temperatures, making it an important option for sustainable dyeing processing technology. This study investigated the enzymatic dyeing of cotton and silk fabrics using six phenolic monomers (catechol, hydroquinone, 2-aminophenol, 4-aminophenol, 1,4-phenylenediamine and 2,5-diaminobenzenesulphonic acid) via oxidative polymerisation catalysed by horseradish peroxidase (HRP). The research explored the colouring mechanism, functional attributes and dyeability of the fabrics. The polymerisation mechanism of the polymer was elucidated through liquid chromatography–tandem mass spectrometry, while the functional and morphological characteristics of the dyed fabric were examined via Fourier transform–infrared spectroscopy, thermogravimetric analysis and scanning electron microscopy imaging. The dyed fabric underwent dyeability assessments, including colour depth analysis and various fastness tests. Under mild reaction conditions, nearly all the phenolic monomers successfully dyed both the silk and cotton fabrics using HRP. The dyed fabrics demonstrated enhanced thermal stability and dyeability. However, the cotton fabrics exhibited worse dyeability and fastness than the silk fabrics, with noticeable stains on their surfaces when dyed with certain phenols. These findings underscore the suitability of enzymatic oxidative dyeing for protein fibres over vegetable fibres, as well as the importance of tailoring enzymatic dyeing processes for vegetable fibres.