Effect of immobilized cellulase enzyme treatment on properties of ramie fabric

In this study, Eudragit S-100 has been covalently bound to the cellulase enzyme to form immobilized cellulase enzyme and then the effect of the treatment on ramie fabric properties is studied. The ramie fabrics treated with immobilized cellulase enzyme show lower quantities of reducing sugar, weight loss, and higher tensile strength than native cellulase enzyme-treated fabrics. Scanning electron microscopic analysis shows that the surface of ramie fabrics treated with cellulase enzyme is smoother than that of the untreated sample. Furthermore, treatment by the immobilized cellulase enzyme is less damaging to the fibres. X-ray diffraction studies show that there is hardly any loss in the crystallinity of ramie fabrics. Low-stress mechanical properties evaluated by the Kawabata Evaluation System for Fabric indicate that immobilized cellulase enzyme treatment improves the softness, flexibility, and elastic recovery of the ramie fabrics

Disulfide bond reconstruction: A novel approach for grafting of thiolated chitosan onto wool

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.Chitosan, a natural biopolymer, is used as a multifunctional agent for modification of wool either through chemical crosslinking or physical coating. For the first time, wool fabric has been modified with chitosan through disulfide bond breaking and reforming reactions. The chitosan was thiolated and then grafted onto the reduced wool fibers through disulfide bonds. In order to understand the mechanism of the grafting of thiolated chitosan onto wool, glutathione was used as a model compound for wool in the research. The structures of thiolated chitosan reacted with glutathione and wool fabrics grafted with thiolated chitosan were investigated by FTIR, 13CNMR, XPS, XRD, SEM. The dyeability, shrink-resistance and biocompatibility were also tested. The results suggested that glutathione reacted with thiolated chitosan and formed disulfide bond. The thiolated chitosan-grafted wool fabric had good shrink-resistance and dyeability. Hydrophilicity and antibacterial properties were also improved compared with untreated wool fabric. The results provide a novel approach for modification of wool through fiber-intrinsic groups like disulfide bonds

Chitosan-Templated Bio-coloration of Cotton Fabrics via Laccase-Catalyzed Polymerization of Hydroquinone

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.There is an increasing interest in the development of enzymatic coloration of textile fabrics as an alternative to conventional textile dyeing processes, which is successful for dyeing protein fibers. However, unmodified cotton fabrics are difficult to be dyed through enzyme catalysis due to the lack of affinity of biosynthesized dyes to cotton fibers. In order to improve the enzyme‐catalyzed dyeability of cotton fibers, chitosan was used to coat cotton fabrics as template. A novel and facile bio‐coloration technique using laccase catalysis of hydroquinone was developed to dye chitosan‐templated cotton fabrics. The polymerization of hydroquinone with the template of chitosan under the laccase catalysis was monitored by ultraviolet‐vis spectrophotometer on the absorbance of reaction solution. A significant peak of UV‐vis spectrum at 246 nm corresponding to large conjugated structures appeared and increased with increasing the duration of enzymatic catalysis. The effect of different treatment conditions on the laccase‐catalyzed dyeing of cotton fabric was investigated to determine their optimal parameters of laccase‐catalyzed coloration. Fourier‐transform infrared spectroscopy spectra demonstrated the formation of H‐bond and Schiff base reaction between chitosan and polymerized hydroquinone. Scanning electron microscopy indicated that the surface of dyed cotton fiber was much rougher than that of the control sample. Moreover, X‐ray photoelectron spectroscopy also revealed the existence of the chitosan/polymerized hydroquinone complex and polymerized hydroquinone on the dyed cotton fibers. This chitosan‐templated approach offers possibility for biological dyeing coloration of cotton fabrics and other cellulosic materials

Enzymatic thiol-ene click reaction: an eco-friendly approach for MPEGMA-grafted modification of wool fibers

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.The thiol–ene click reaction has been commonly used for the modification of many materials due to its high efficiency, high selectivity, and reliability. To further promote the sustainable technology for the modification of keratin-based materials, enzymatic biotechnology and thiol–ene click chemistry was integrated for the first time for grafting modification of wool fibers with methoxy polyethylene glycol methacrylate (MPEGMA). Wool fibers were reduced to create thiol groups and then grafted with MPEGMA through a horseradish peroxidase (HRP)-mediated thiol–ene click reaction. In order to understand the grafting mechanism of MPEGMA on wool, l-cysteine was used as a model compound for the thiol group of the reduced wool in the current research. The structures of MPEGMA reacted with l-cysteine and grafted on wool fabrics were investigated by FTIR, MALDI-TOF, Raman spectra, and XPS. The surface morphology, wettability, moisture penetrability, and regain of modified wool fibers were also assessed. The results showed that l-cysteine reacted with MPEGMA through the thiol–ene click reaction. The MPEGMA-grafted wool fabric had good surface wettability, and its moisture penetrability and regain were also improved when compared with untreated wool fabric. The HRP-initiated thiol–ene grafting reaction not only encouraged green and sustainable click chemistry but also provide an alternative eco-friendly approach for modification and functionalization of keratin and keratin-containing materials

Laccase-mediated dye-free coloration of wool fabric

In this study, an investigation on a novel coloring technique, based on laccase-mediated radical coupling of amino acidmolecules of wool fibres, has been carried out. Firstly, the influence of temperature, incubation time, and pH on the K/Svalue and hue angle (h) of the colored wool fabrics is studied. Analysis of levelness of coloration, wash fastness, rubfastness, and UV-protection factor of the colored wool fabrics has been done. Then, the surface morphology and structure ofthe wool fibres are analyzed by scanning electron microscopy (SEM) and Fourier transform Infrared spectroscopy (FTIR).The enzymatic coloration processes are carried out in an acetate-sodium acetate buffer medium (pH 5) at 50 C for 24 h andthe colored wool fabrics show good color fastness and uniformity. The results obtained are as per the requirements of textilecolor fastness. SEM study shows that no particles are adhered to the surface of the wool fibres. The results of FTIR andultraviolet-visible spectroscopy show that the obvious oxidation coupling reactions take place between the molecules in thepolypeptide chains of the wool

Hydrophobic functionalization of jute fabrics by enzymatic-assisted grafting of vinyl copolymers

We report an eco-friendly approach to improve the hydrophobicity of jute fabrics via horseradish peroxidase (HRP)-catalyzed covalent grafting of butyl acrylate (BA) and 2,2,3,4,4,4-hexafluorobutyl methacrylate (HFBMA). Hydrophobic vinyl monomers were grafted onto the exposed lignin molecules of the jute surface by free-radical polymerization in the presence of a HRP/H2O2/acetylacetone (ACAC) system. Coupling onto the lignin-jute surface was demonstrated by attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), solid-state nuclear magnetic resonance (solid-state 19F NMR), elemental analyses, X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray spectroscopy (EDS), matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF MS) and scanning electron microscopy (SEM). The hydrophobicity and oleophobicity of modified jute fabrics was estimated in terms of contact angle and wetting time. The results indicated that it was essential to attain vinyl monomers grafting polymerization onto jute surfaces in a HRP/H2O2/ACAC system. Moreover, the grafting of vinyl monomers led to hydrophobicity increases of 53.86% and 61.03% in the contact angle of grafted jute fabrics with BA and HFBMA when compared with unmodified jute fabrics, respectively. Both vinyl monomers demonstrated high propensity to be polymerized by HRP in the presence of H2O2, and acquired the ability to act as high-performance composites with hydrophobic resins.This work was financially supported by the National Natural Science Foundation of China (51673087, 51603087), Fundamental Research Funds for the Central Universities (JUSRP51717A), the Programme for Changjiang Scholars and Innovative Research Teams at University (IRT_15R26), the Portuguese Foundation for Science and Technology (UID/BIO/04469/2013 unit) and COMPETE 2020 (POCI-01-0145-FEDER-006684).info:eu-repo/semantics/publishedVersio

Laccase-catalyzed polymerization of hydroquinone incorporated with chitosan oligosaccharide for enzymatic coloration of cotton

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.Chitosan oligosaccharide (COS), a water-soluble carbohydrate obtained from chemical or enzymatic hydrolysis of chitosan, has similar structure and properties to non-toxic, biocompatible, and biodegradable chitosan. However, COS has many advantages over chitosan due to its low molecular weight and high water solubility. In the current work, COS was incorporated in the laccase-catalyzed polymerization of hydroquinone. The laccase-catalyzed polymerization of hydroquinone with or without COS was investigated by using simple structure of glucosamine hydrochloride as an alternative to COS to understand the mechanism of COS-incorporated polymerization of hydroquinone. Although polyhydroquinone can be regarded as the polymeric colorant with dark brown color, there is no affinity or chemical bonding between polyhydroquinone and cotton fibers. Cotton fabrics were successfully in-situ dyed into brown color through the laccase-catalyzed polymerization of hydroquinone by incorporating with COS as a template. The presence of COS enhanced the dye uptake of polyhydroquinone on cotton fibers due to high affinity of COS to cotton and covalent bonding between COS and polyhydroquinone during laccase catalysis. This novel approach not only provides a simple route for the biological coloration of cotton fabrics but also presents a significant way to prepare functional textiles with antibacterial property

Laccase-catalyzed polymerization of diaminobenzenesulfonic acid for pH-responsive colour-changing and conductive wool fabrics

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.In recent years, there has been an extensive interest in the research of smart fabrics and functional textiles. The present work has successfully developed the enzymatic approach for dyed wool fabrics in possession of special pH-responsive colour-changing and conductive properties, via in-situ polymerization of 2,5-diaminobenzenesulfonic acid (DABSA) by laccase from Trametes versicolor. The enzymatically synthesized product, poly(2,5-diaminobenzenesulfonic acid) (PDABSA), were characterized by FT-IR, UV-Vis spectrophotometry and matrix assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS). The redox property and thermal stability of the polymer products were studied by cyclic voltammetry (CV) and TGA analysis, respectively. The results proved that the resulting polymer reached to 2 KDa and showed strong pH-dependence of UV-Vis absorption, electrochemical activity and high thermal stability. Utilizing the doping/dedoping process of PDABSA, the dyed wool fabrics were endowed with a pH-dependent redox potential. Furthermore, the dyed wool fabrics exhibited reversible colour change from dark purple at pH 1.8 to yellowish-brown at pH 10.0, indicating that the PDABSA showed unusual pH-dependent colour-changing properties on dyed wool fabrics

Laccase-catalyzed poly(ethylene glycol)-templated ‘zip’ polymerization of caffeic acid for functionalization of wool fabrics

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link

Changes on content, structure and surface distribution of lignin in jute fibers after laccase treatment

Effect of laccase treatment on the content, structure, and surface distribution of lignin in jute fibers were fundamentally investigated. Four percent lignin was removed from jute fibers via the laccase treatment. The residual lignin in the laccase-treated jute fibers showed increased molecular weights, which indicated polymerization between lignins on jute fibers. Meanwhile, the phenolic hydroxyl content in lignin decreased during the laccase oxidation accompanied by demethylation of methoxyl groups and generation of carbonyl groups. Due to the degradation and subsequent polymerization of lignin by laccase, the bulgy lignins on jute fiber surfaces were redistributed, which made the surface neat and glossy.This work was financially supported by the National Natural Science Foundations of China (51603087, 51673087), Program for Changjiang Scholars and Innovative Research Team in University (IRT_15R26), Fundamental Research Funds for the Central Universities (JUSRP51717A), Key R&D Program of Jiangsu Province (BE2016208), Portuguese Foundation for Science and Technology (UID/BIO/04469/2013 unit), and COMPETE 2020 (POCI-01-0145-FEDER006684).info:eu-repo/semantics/publishedVersio