Modification Of Wool Research Articles

Biodegradation and valorization of feather waste using the keratinase-producing bacteria and their application in environmentally hazardous industrial processes

Poultry feathers are widely discarded as waste worldwide and are considered an environmental pollutant and a reservoir of pathogenic bacteria. Therefore, developing sustainable and environmentally friendly methods for managing feather waste is one of the important environmental protection requirements. In this study, we investigated a rapid and eco–friendly method for the degradation and valorization of feather waste using keratinase–producing Pseudomonas geniculata H10, and evaluated the applicability of keratinase in environmentally hazardous chemical processes. Strain H10 completely degraded chicken feathers within 48 h by producing keratinase using them as sources of carbon, nitrogen, and sulfur. The culture contained a total of 402.8 μM amino acids, including 8 essential amino acids, which was higher than the chemical treatment. Keratinase was a serine-type metalloprotease with optimal temperature and pH of 30 °C and 9, respectively, and showed relatively high stability at 10–40 °C and pH 3–10. Keratinase was also able to degrade various insoluble keratins such as duck feathers, wool, human hair, and nails. Furthermore, keratinase exhibited more efficient depilation and wool modification than chemical treatment, as well as novel functionalities such as nematicidal and exfoliating activities. This suggests that strain H10 is a promising candidate for the efficient degradation and valorization of feather waste, as well as the improvement of current industrial processes that use hazardous chemicals.

Influence of liquid ammonia on the structure of wool fiber

Liquid ammonia treatment of worsted fabric was carried out by a continuous liquid ammonia finishing machine, and the effects of liquid ammonia on wool surface morphology, chemical structure and crystallinity were studied and corresponding mechanism was discussed in detail. The results showed that liquid ammonia made the surface scales of wool remove partially and decreased the content of hydrophobic lipid layer and hydrophobic property. After liquid ammonia treatment, the secondary structure of wool macromolecule was changed, manifested in increased α-helix and decreased β-sheet; the disulfide bonds were broken to form cysteine sulfonate, cysteic acid and cystine oxides. Liquid ammonia increased the content of α-crystallization, causing an increase in the crystallinity of wool. As our knowledge goes, this is the most systematic report to date on the effect of liquid ammonia on the structure of wool fiber, and provides a novel medium for the modification of wool in a large scale. Furthermore, it also provides a theoretical basis for the commercial application of liquid ammonia as a non-aqueous medium in wool textile industry.

Thermally stable micro-sized silica-modified wool powder from one-step alkaline treatment

Across the world, waste wool generated in farms and textile industries is often discarded without any utilisation. Low thermal stability of wool, i.e., melting of α-helix near 160 °C and degradation around 185–210 °C, further limits its use where a higher temperature is required. In the past, wool powder with slightly enhanced thermo-stability has been prepared using ionic liquids (from those containing toxic imidazole and pyridine), though the search for finding a sustainable and economic alternative is still ongoing. The current study proposes a conversion method of wool waste into highly thermo-stable micro-sized silica-modified powder through controlled disintegration of wool using a single-step chemical treatment. This study for the first time, reports an optimised method of wool powder preparation using sodium silicate solution while also maintains comparatively lower chemical to wool ratio among the previous reports. The properties of chemically prepared powder were thoroughly compared with powder of similar size prepared using mechanical milling. The chemical modification of wool showed improvement in its crystalline structure through α-helix to β-sheet transition and reduction in the interlayer spacing. The known high thermal stability of silicate groups significantly enhanced the thermal stability of the modified wool, given only 12–38% weight loss was recorded even at 600 °C. Overall, this research reveals an innovative method of transforming waste wool into thermally stable micro-sized powder for potential wider applications, such as high temperature extrusion, 3D printing, thermo-resistive coating, insulation in automotive and construction industries.

The Absorption Accelerating Behavior of Surface Modified Wool: Mechanism, Isotherm, Kinetic, and Thermodynamic Studies

ABSTRACT Even though wool has excellent fabric properties, its low absorption capacity hinders its efficient application in the textile industry and material field. Surface modification is one of the efficient ways of improving its inherent properties. However, the effect of surface modification on its absorption properties is not well understood. Herein, surface modification of wool was performed using deep eutectic solvent method. Several physical and chemical properties of the modified wool including chemical bonds, surface topography, and absorption capacity were analyzed. FTIR revealed that surface modification retained keratin molecular structure but only cleaved disulfide bonds. The second-derivatization of FTIR spectra further indicated that the secondary structure was also retained. SEM and EDS analyses revealed that scale modification etched the wool surface. Together, these changes improved the absorption capacity of wool. BET further revealed that surface modification increased the pole size of wool, a property that improves the adsorption capacity. Further analyses on diffusion coefficient, adsorption isotherm, adsorption kinetics, and thermodynamic parameters at a lower temperature revealed that surface modification followed Langmuir to Freundlich isotherm and pseudo-first-order model to pseudo-second-order model transformation. In particular, the adsorption content, rate and diffusion coefficient increased with decrease in the entropy and enthalpy of wool.

Thiol-Based Ionic Liquid: An Efficient Approach for Improving Hydrophilic Performance of Wool

ABSTRACT Research suggests that to eliminate undesirable effects of the scale layer, natural wool needs to be surface-modified before further application to textile manufacture, obtaining better properties of shrink-resistance, washing/felting and dyeing. However, previous methods exhibited some disadvantages, such as the adsorbable organic halogens (AOX) pollution from chloride treatment and severe fiber damage caused by enzyme treatment. Therefore, thiol-based ionic liquid was introduced onto the surface modification of wool to counter these defects. In this modification process, the surface modification was controlled on the wool surface using scanning electron microscopy (SEM) with evaluation of the effects of cleavage of disulfide bonds ascertained by the X-ray energy dispersive spectroscopy (EDS) results. The solubility in alkali and Fourier transform infrared spectroscopy (FTIR) spectra further indicated that the process could prevent main body damage of the fiber, the decreased content of the α-helix structure was evaluated from X-ray diffraction (XRD) and differential scanning calorimeter (DSC) curves. Furthermore, the hydrophilic performance of the modified wool, including wettability and the dye-ability, revealed an apparent enhancement compared to that of raw wool. In a summary, the thiol-based ionic liquid approach can efficiently improve hydrophilic properties of wool, and has the potential for large-scale production.

Benign Felt-proofing of Wool Fibers Using a Keratinolytic Thermophilic Alkaline Protease

ABSTRACT Felting shrinkage of wool is a major problem which has negative impacts on its performance attributes. Traditional chemical methods used for shrink-resist finishing are suffering from some drawbacks. Therefore, this work aimed at the utilization of microbial protease in wet processing of wool. The bacterial strain Bacillus licheniformis ALW1 produced 52.1 U/mL enzyme activity that was thermophilic with optimum activity at pH 9. Additionally, the enzyme possessed a keratinolytic activity of 4.1 U/mL, suggesting its applicability in wool processing. Therefore, the effects of different treatment conditions; Viz. concentration of the enzyme, temperature, treatment period and pH on some of the physical and chemical characteristics of wool were studied. The felting shrinkage of wool fibers was determined using the Aachener 3-D felting machine. The influence of the enzymatic modification of wool on its dyeability with anionic dye was assessed. Chemical, physical, and mechanical properties of treated samples were evaluated using amino acid analysis, alkali solubility, Fourier Transform Infrared spectroscopy, whiteness index, and tensile properties. Scanning electron microscopy was applied for the examination of wool fibers’ surface. The results proved that the modification of wool fibers with the produced enzyme highly improved their felting resistance and dyeability with acid dye without adverse effects on its inherent properties.

Modification of Wool via Grafting β-cyclodextrin Oxidized by Sodium Periodate

The modification of wool fabrics is significant in preparation of functional textiles. Sodium periodate oxidized β-cyclodextrin was grafted onto wool fabric through Schiff base reaction to obtain fabric with controlled release property. β-cyclodextrin was oxidized to aldehyde-β-cyclodextrin, and the results show that the inclusion constant and aldehyde content of aldehyde-β-cyclodextrin are varied with the reaction parameters such as molar ratio of reaction agents and the reaction temperature. The degree of oxidation was confirmed by ion chromatography. The drug loading test shows that the oxidized cyclodextrin still had inclusion ability towards phenolphthalein, while the inclusion constant was only 50 % of the original β-CD. The ATR-FTIR spectra proved the occurrence of grafting reaction between the aldehyde groups of aldehyde-β-cyclodextrin and the amino groups on wool fiber. The aldehyde-β-cyclodextrin grafted wool fabric show great washing durability even after 5 washing cycles. Compared with the aldehyde-β-cyclodextrin power, the inclusion ability of aldehyde-β-cyclodextrin fixed on the wool fiber decreased by 60 %.

A Facile and Controllable Approach for Surface Modification of Wool by Micro-dissolution

Most modifications of wool focused on its surface due to the existence of the cuticle scales. For instance, chlorination, oxidation and protease treatments were used to break down or remove the scales. However, these modifications usually severely damaged the internal structure of wool. In this paper, a novel approach based on surface micro-dissolution was employed to modify the surface of wool to minimize the internal damage of wool, and improve the surface-related properties of wool. The micro-dissolution system used NaHSO3/urea to dissolve the scale layer of wool. After being micro-dissolved with NaHSO3/urea system, scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), fluorescence microscopy, Fourier transform infrared spectroscopy (FTIR), and the Allworden reaction were utilized to characterize the treated wool. Furthermore, felting shrinkage, strength loss and wettability of the treated wool were determined. The results showed that NaHSO3/urea system could dissolve the scale layer from outside to inside. The fluorescence microscopic images further indicated that low concentration of NaHSO3/urea system can dissolve the surface of wool without the serious damage of internal structure. Moreover, the micro-dissolution system can be controlled to dissolve the scale layer on the surface of wool slightly by adjusting the reaction conditions. The presented method is simple, easy to operate, and economical, thereby can open up new directions for the surface modification of wool.

Application of D‐optimal design in the analysis and modelling of dyeing of plasma‐treated wool with three natural dyes

AbstractBoth the dyeing and finishing of textiles with natural compounds are gaining increasing attention because of various environmental and health problems associated with the use of synthetic reagents. In this study, wool fibres were dyed with three natural dyes, namely, Arnebia euchroma, cotton pods and harmal seeds. Alum was used as the mordant, and samples were mordanted by the premordanting method. Oxygen plasma was employed for the surface modification of wool. Plasma treatment time, alum concentration, dyebath temperature and pH were selected as the process variables, and their effects on the K/S of the dyed samples were analysed using D‐optimal design. The surface topography, morphology and chemistry of the wool fibres after plasma treatment were studied by atomic force microscopy (AFM), scanning electron microscopy (SEM) and Fourier Transform–infrared spectroscopy (FTIR), respectively. FTIR confirmed the creation of new oxygen‐containing groups on the surface of wool fibres after plasma treatment. SEM and AFM images confirmed the surface etching and increase in the roughness of plasma‐treated fibres. Increasing the dyebath pH and temperature increased the K/S of the dyed samples. Increasing the amount of alum mordant increased the K/S of samples dyed with cotton pods but decreased the K/S of samples dyed with A. euchroma and harmal seeds. Increasing the plasma treatment time improved the K/S of samples dyed with A. euchroma and cotton pods but had no significant effect on the K/S of samples dyed with harmal seeds.

Natural dyeing of wool with henna and yarrow enhanced by plasma treatment and optimized with response surface methodology

In this study, response surface methodology was employed for optimization of natural dyeing of wool with henna leaves and yarrow flowers. As natural dyes have generally low affinity towards textile fibers and need considerable amounts of metal mordants to be absorbed satisfactorily, plasma treatment was used as an environmentally friendly pretreatment to enhance the dyeability and lower the amount of mordant needed. The results showed that the color value of the samples increased by increasing the plasma treatment power, dyebath temperature, and alum mordant concentration. However, the color value was higher at lower pH values. ATR-FTIR, SEM, and AFM investigations confirmed the significant surface chemical and topographical changes of the fibers. Plasma treatment can be considered as an alternative of wet chemical treatments for surface modification of wool to improve its dyeability and reduce the need for potentially toxic metallic mordants.

Eco-friendly Grafting of Chitosan as a Biopolymer onto Wool Fabrics Using Horseradish Peroxidase

Chitosan and enzymes have been extensively used in modification of wool, due to their non-toxic and eco-friendly characteristics, as well as to reduce pollution in textile production. In the present work, chitosan was grafted onto wool fabrics using horseradish peroxidase (HRP) in order to endow wool with outstanding properties. The reaction mechanism, grafting percentage, and properties of chitosan-grafted pretreated wool fabric including wettability, dyeability, shrink resistance, and antibacterial activity were studied. P-hydroxyphenylacetamide (PHAD), as a model compound for tyrosine residues in wool, was used to study the mechanism of HRP-mediated grafting of chitosan onto wool. UV and FTIR analyses indicated that quinones, which are intermediate of HRP/H2O2-catalyzed PHAD, reacted with the amino groups of chitosan by Schiff base or Michael addition reactions. Scanning electron microscopy (SEM) showed that dichloroisocyanuric acid pretreatment had an etching effect and some substances were deposited onto the wool fiber. SEM and Fourier transform infrared (FTIR) spectroscopy further confirmed the covalent grafting of chitosan onto wool. Compared with chitosan-grafted unpretreated wool, there was an obvious improvement in grafting efficiency of chitosan onto wool fabric, physical and mechanical properties after pretreatment and chitosan grafting on the wool. For chitosan-grafted pretreated wool fabrics, there was no observable change in the thermal behavior, while the hydrophilicity, dyeability, shrinkage resistance, and antibacterial activity were remarkably improved compared to that of untreated wool. The present work offers a new ecologically acceptable process of grafting chitosan on the wool.

Ammonia ligand and transition metal salt complexation on naturally dyed textile surface: A reflectance spectroscopic investigation to understand coloration and fastness properties

Ammonia is a stronger ligand and can replace water molecules in a chelate metal complex as per spectrochemical series. This property of ammonia was utilized in this work for the coloration of wool in order to obtain some unusual effects. Different concentrations of ammonia solution was applied on Butea monosperma flower extract dyed wool previously premordanted with ferrous sulfate salt to evaluate the effect on colorimetric properties. A range of newer shades were produced on wool substrates which were characterized in terms of K/S, CIELa*b* values and fastness properties. The observed effects exhibited on wool and acceptable fastness properties of produced shades points out a promising approach for developing environmentally sustainable colorful textile materials and clothing. The chemical modification of wool before and after application of ammonia was also evaluated using Fourier transform infrared spectrometer analysis. © 2019 American Institute of Chemical Engineers Environ Prog, 38:e13146, 2019

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

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.

An ecofriendly phosphorylation of wool using Maillard reaction for improving cationic dye absorption

Abstract Phosphorylated wool with enhanced ability to absorb cationic dyes is helpful to dye wool fabrics using cationic dyes with good dyeing properties, which is more economic and ecofriendly compared to the traditional dyeing process of acid dyes with poor wet fastness. Phosphorylation can be performed by applying chemical reagents which tend to cause a problem of environmental pollution and the fibers can be damaged seriously under harsh reaction conditions, or using enzymes which are currently somewhat discouraged due to significant cost of the enzymes and their decreased stability at the reaction conditions. In this study, non-toxic glucose 6-phosphate was applied to phosphorylated modification of wool via Maillard reaction under a mild condition to enhance the dyeing properties of wool fabric for cationic dyes. The reaction between glucose 6-phosphate and wool keratin was demonstrated from the results of sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), particle diameter, Fourier transform infrared spectra (FTIR) and Energy Dispersive X-ray test (EDS). It was found that phosphorylation modification scarcely changed the mechanical properties of the wool fabric. Maillard browning on the wool could be avoided by accurately controlling the reaction time. Dyeing properties of phosphorylated wool fabric with cationic dyes were markedly enhanced. The exhaustion of phosphorylated wool fabric for two cationic dyes: Cationic Brilliant Red 5 GN and Brilliant Yellow B 6 GL increased from 38.6% to 18.9%–84.5% and 67% respectively by comparing with that of the wool fabric without modification and better color strength (K/S) and very good wash fastness properties obtained. The results indicated that phosphorylated modification of wool with glucose 6-phosphate could be a potential, safe and cleaner approach to develop a more efficient and economic dyeing process for wool fibers with cationic dyes.

Synthesis of acid dyes containing polyetheramine moieties and their low‐temperature dyeing properties on wool fiber

ABSTRACTTo realize the low‐temperature dyeing of wool fibers, the use of auxiliaries and wool modification are common methods. Low‐temperature auxiliaries may cause water‐pollution problems, and wool modification is a costly and uncontrollable process. In this study, new acid dyes, named D1–D3, containing polyetheramine groups were synthesized and applied to wool fiber by conventional and low‐temperature exhaust dyeing procedures. The results indicate that the new acid dyes could interact with wool‐fiber‐like auxiliaries and render a high exhaustion rate to the wool fiber at a dyeing temperature of 80 °C. In comparison with Acid Blue 25, the D1–D3 dyes showed an increased dyeing rate, especially under a dyeing temperature of 80 °C. Despite the bigger relative molecular masses of D1–D3, the exhaustion rates of D1–D3 were still higher, and the times of half‐dyeing were shorter than that of Acid Blue 25. The color differences between the wool fabrics dyed with the four dyes at 80 and 98 °C, respectively, were compared. We found that the color differences of D1–D3 between 80 and 98 °C were smaller than that of Acid Blue 25. The interactions between the dyes and wool fiber were analyzed and manifested by the measurement of the ζ potential of the dyes and wool fiber. The leveling and transfer properties of the D1–D3 dyes were also investigated, and the color differences of the wool fabrics dyed with Acid Blue 25, D1, and D2 were very low at all measured pH values and temperatures. The fastnesses of D1–D3 on wool fabric were almost the same as that of Acid Blue 25. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45793.

Examining a change in the properties of coarse wool fiber under the influence of electrical discharge treatment

Modification of coarse wool fibre is a basic condition for improving quality of the manufactured woolen textile products while reducing their cost. Traditional methods of modification of wool are expensive, that is why the implementation of these methods into existing technological modes is not always economically justified. The obtained effect of modification is often associated with undesirable damage of protein structure of fiber. A solution to this problem is the application of electric discharge treatment, accompanied by the emergence of electric discharge non-linear bulk cavitation. It is shown that the influence of electrohydrolic shock and products of water cleavage on wool does not cause profound destruction of keratin, in contrast to enzymatic and plasmochemical methods of treatment. Based on the performed experimental studies, it was determined that during electric discharge treatment of coarse wool there occurs the compaction of fiber cuticles and a change in supramolecular structure of keratin. This fact predetermines a decrease in felting ability of wool fibre, an increase in sorption properties, as well as in resistance to hydrolysis and influence of oxidants and reductants. It was established that the application of electric discharge treatment as a method of coarse wool modification would contribute to a decrease in shrinking and improvement of optimized dyeing of woolen textile material. Thus, the proposed technology of wool improvement will make it possible to use less expensive raw materials for the production of textile materials for different purposes.

Surface Modification of Wool Fabric with Chitosan and Gamma Radiation

Surface modification of wool was done with chitosan, gamma radiation and combined chitosan/gamma radiation to analyze how polymer loading%, k/s value, dye uptake% and wash fastness property vary of the dyed fabric. In this investigation scoured and bleached knitted wool fabric was treated with 0.1%, 0.3%, 0.5%, 0.7% and 1% chitosan and polymer loading was found as of 1.21%, 1.38%, 0.32%, 0.14% and 0.48% respectively. It was found that polymer loading % increase significantly with the decrease of chitosan concentration % up to a certain limit. Some samples were irradiated with 5kGy, 10kGy, 20kGy and 50kGy gamma radiation individually. Combined chitosan/gamma treatment was carried out by treating with 0.1% chitosan followed by treatment with 5kGy, 10kGy, 20kGy and 50kGy gamma radiation. The infrared spectrum of wool specimens were analyzed by Fourier Transform Infrared Spectrometer (FT-IR). It was found that the infrared spectrum of untreated and treated wool specimens were approximately same except the peak absorbs at 1340-1265 cm-1 which indicate the C-N stretch absorption of aromatic amines. After dyeing k/s value of untreated and treated wool specimens were measured using Data color 600®. There was a remarkable variation of k/s value on different treatment process. Dye uptake% of untreated and treated wool specimens were determined by using UV Visible Spectrophotometer in terms of absorbency. Color fastness to wash was measured using ISO standard. There was no significant change of wash fastness property of treated and untreated wool.

A cleaner and eco-benign process for wool dyeing with madder, Rubia tinctorum L., root natural dye

In this study, an alternative cleaner process over traditional metallic mordanting process for wool dyeing with madder, Rubia tinctorum L., root natural dye was presented. Wool surface was modified with novel eco-friendly and biocompatible cationizing agent having numerous free amine groups, namely chitosan–polypropylene imine dendrimer hybrid (CS-PPI). Modified wool demonstrated remarkable increase in dye uptake as compared to raw wool. Optimal dyeing results were obtained when CS-PPI 7 %, madder dye 20 % and dyeing pH 7 were employed. Dyeing results such as percent dye exhaustion and color depth emphasized auxiliary agents, i.e., metallic mordant and acid could be eliminated from wool dyeing process with madder dye. Saturation point shifted to lower dye concentrations in the treated wool suggested the same color depth could be obtained using lower amount of crude dye material. Wool modification with CS-PPI demonstrated no adverse impact on other properties such as colorfastness and color shade characteristics. In addition, treated wool exhibited excellent antimicrobial activity (nearly 100 % microbial reduction) against two common pathogenic microorganisms, Escherichia coli and Staphylococcus aureus which were almost durable after dyeing and subsequent repeated washes. In general, the results of this investigation showed that CS-PPI can be employed as an alternative eco-friendly “bio-mordant” as well as effective antimicrobial finishing material in wool dyeing with madder dye.

The Dissolution of Wool in Alkali Solution and the Changes of Fiber Structure and Performance

The dissolution of wool in 4g/L NaOH solution at 65°C is used to be a standard test method for the damage of wool in the processing. This suggests that alkali can cause wool keratin and the linkage between molecule chains broken. Fortunately, the dissolution of wool at low temperature is mainly limited on the surface scales because the swelling of wool in water solution at lower temperature is quite small. In this paper, the dissolution of wool in alkali solution and the changes of the fiber structure and performance at different temperature were investigated. The results showed clearly that the wool surface keratin could be dissolved in different extent with the varying of the temperature and this could be applied to develop an AOX free modification of wool for shrinkage resistance.

Modification of wool by air plasma and enzymes as a cleaner and environmentally friendly process

Abstract A big disadvantage of the traditional anti-felting modification of wool is the problem of environmental pollution. Low temperature plasma (LTP) and enzyme process are the two important cleaner technologies which have potential use in the textile industry. In this paper, transglutaminase, a protein crosslinking enzyme, combined with air low temperature plasma and protease was used to modify wool fiber. The influences of the combination treatment on wool knitgoods performances were discussed. It was shown that air low temperature plasma pretreatment, instead of conventional chemical pretreatment, improved wettability significantly and made enzyme molecule more accessible to protein chains of the wool. Protease treatment following air plasma impacted a significant reduction in fabric shrinkage and the loss of strength was under control. Transglutaminase remediated wool damage, resulting in an increase in bursting strength. The machine washable wool knitgoods are obtained and the damage to the wool fiber can be controlled by using the combination treatment of air plasma, protease and transglutaminase. TGase was demonstrated to catalyze cross-linking reaction in wool protein by analyzing the thermal behavior of wool.