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Blend films of keratoses and sericin were prepared using water as a common solvent and glycerol as a plasticizer. An aqueous solution of keratoses extracted from wool via oxidation using peracetic acid was added with different amounts of sericin from silk degumming and blended along with glycerol to obtain films by solution casting method. All the different concentrations of keratoses/silk sericin (KOx/SS) films are observed to be in intact condition. Blend films were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, thermal analysis, water uptake and tensile behavior. Only the cast films of 100% keratoses show a smooth surface indicating good miscibility between keratoses and plasticizer, while increasing the amount of sericin the film surface becomes rough. Fourier transform infrared analysis pointed out that the polymers have no covalent interaction with each other. The addition of glycerol to 100% sericin films strongly decreases their thermal stability changing their secondary structure as shown by FT-IR and thermal analysis. A similar behavior was not seen in keratoses. Sericin plasticized film with glycerol shows low mechanical properties, but the addition of 10% of keratoses to the blend strongly enhances the tensile strength of cast films, while the addition of small amounts sericin to keratoses slightly increases its water uptake.

Blend films of polyvinyl alcohol (PVA) and keratoses (KOx) were prepared using water as a common solvent. Aqueous solution of KOx from wool was extracted via oxidation using peracetic acid, and different amounts of PVA were added and blended to obtain films by solution casting method. Blend films were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, differential scanning calorimetry and tensile measurement. The scanning electron microscopy investigation showed that with decreasing PVA amount, film surface becomes rough and uneven. Thermal behavior and Fourier transform infrared analysis pointed that the two polymers have no covalent interaction each other. Also, it is to be noted that increasing the amount of PVA in the blend from 70 to 100% improved the tensile strength of blend films, and the elongation at break increases dramatically in films containing 70–100% of PVA. Moreover, blends containing 90 and 100% of KOx were too brittle for films production.

Cashmere plays an important role in luxury factory due to its characteristic. In frame of "green economy", many companies start to produce and market recycled cashmere textiles [1]. In order to have a correct identifiation of fiers, NIR spectroscopy can be applied to analyze and distinguish virgin and recycled cashmere fiers. Since no signifiant diffrences can be seen in the recorded spectra, the PCA analysis combined with the SIMCA method allows the classifiation of the fiers in two distinct classes. Quantitative analysis was carried out using samples obtained by carefully mixing known amounts of recycled and virgin cashmere fiers. These preliminary results confimed that the NIR coupled with chemometric methods might be a useful tool for a rapid screening of cashmere fiers quality.

Low quality coarse wool from Italian sheep is a large biomass unavoidably joined to sheep farming and it is to be disposed or adequately managed. Management of shorn wool (from 14000 to 16000 tons/ year in Italy) mainly implies scouring processes and related costs. Waste wool scouring provides wool wax, further refied into lanolin, in 5-20% yield and washed low-quality coarse wools. Waste wool scouring would become profiable if scouring process optimization and further valorisation of lanolin could be associated to the scarcely remunerative non-textile uses of washed low-quality coarse wools. In this study optimization of waste wool scouring and wool wax/lanolin recovery by green solvent was carried out using cyclopentyl methyl ether in comparison with conventional solvents like diethyl ether and hexan. The extraction study shows that cyclopentyl methyl ether shows higher amount of grease extraction in comparison with conventional solvents. The presence of residual grease on wool samples after solvent extraction was analyzed using FT-IR spectroscopy and resulted in similar effiency of extraction in comparison with conventional solvents.

Cashmere is a luxury, and expensive fier, objective and quantitative methods to identify and possibly quantify recycled cashmere are crucial to discourage adulteration of high-quality virgin cashmere with cheaper recycled fiers. This work investigates objective methodologies to quantify the amount of recycled cashmere, based on their diffrent dye absorption capacity. Pure virgin and recycled cashmere fires, along with recycled and virgin cashmere blends, were stained with C.I. Direct Red 7, and the exhaust dyebaths were analysed by UV-visible Spectroscopy in order to quantify the residual unabsorbed dye.

Pulsed electromagnetic field (PEMF) has drawn attention as a potential tool to improve the ability of bone biomaterials to integrate into the surrounding tissue. We investigated the effects of PEMF (frequency, 75 Hz, magnetic induction amplitude, 2 mT, pulse duration, 1.3 ms) on human osteoblast-like cells (SAOS-2) seeded onto wool keratin scaffolds in terms of proliferation, differentiation, and production of the calcified bone extracellular matrix. The wool keratin scaffold offered a 3D porous architecture for cell guesting and nutrient diffusion, suggesting its possible use as a filler to repair bone defects. Here, the combined approach of applying a daily PEMF exposure with additional osteogenic factors stimulated the cells to increase both the deposition of bone-related proteins and calcified matrix onto the wool keratin scaffolds. Also, the presence of SAOS-2 cells, or PEMF, or osteogenic factors did not influence the compression behavior or the resilience of keratin scaffolds in wet conditions. Besides, ageing tests revealed that wool keratin scaffolds were very stable and showed a lower degradation rate compared to commercial collagen sponges. It is for these reasons that this tissue engineering strategy, which improves the osteointegration properties of the wool keratin scaffold, may have a promising application for long term support of bone formation in vivo.

A large amount of wool produced in the EU region is coarse and of low quality. The limited or nonutilization of such coarse wool leads to landfilling causing environmental pollution. In this paper, we studied the properties of keratin hydrolyzate, produced by a sustainable hydrolysis process, to be used as a foaming agent in foam dyeing of cotton and wool fabrics. This is a preliminary step on the way to find possible applications which overcome the environmental problem of wool waste and byproducts. We report for the first time the use of keratin hydrolyzate as a foaming auxiliary in the textile dyeing process. The surface tension, molecular weight, foam stability, blow ratio, and bubble size of keratin hydrolyzate in aqueous solutions with and without dyeing auxiliaries were determined. The dyeing influential parameter such as wet pickup was studied to identify their effect on dye fixation and color strength. The foam dyeing was compared with conventional cold-pad batch and pad-steam processes for cotton and wool, respectively. In the investigated variant, keratin hydrolyzate shows a reduction in surface tension, good foam stability along with dyeing auxiliaries, a blow ratio of about 10:1, and 0.02-0.1 mm diameter bubble sizes. These results make possible its application as a foaming agent. Cotton and wool fabrics were dyed using reactive and acid dyes respectively, on a horizontal padding mangle. In both cases, hydrolyzed keratin acts as a carrier for dye molecules and the mechanism of dyeing depends on the respective pH of the dye solution, keratin, and fiber. Foam dyeing of cotton resulted in comparable color strength, while wool shows higher color strength when compared with conventional dyeing processes. Washing and rubbing fastness of cotton and wool foam dyed fabrics are similar to the respective conventional dyed fabrics. The combinations of sustainable keratin hydrolyzate production and its use as an eco-friendly, biodegradable foaming agent in less add on foam dyeing technology resulted not only in saving of large amounts of water and energy but also will be helpful in minimizing a load on effluent and the environment.

The paper reports an overview of the RiceRes project aiming at the multivalorization of all the wastes of the rice value chain, namely straw, husk and bran in order to improve resources eco-efficiency. A wide range of bio-products and bio-materials with different added value has been produced starting from these wastes in the framework of the RiceRes project. Among them, insulating materials for green building have been obtained from rice straw mixed with waste wool, biofillers from husk for polymer composites, mono- and di-glyceride mixtures and high-added value molecules for the food industry from bran.

The project integrates diversified expertises in organic chemistry, medicinal chemistry, biochemistry, microbiology, biocatalysis, materials, engineering and environmental sciences. The objective is the development of sustainable procedures to recover wool wax and lanolin from waste wool. In parallel, ecofriendly physical, chemical and/or biocatalytic methods are devised to exploit these products, recoverable from an abundant discarded biomass such as waste wool, as a source of fatty acids (FAs) and ?-hydroxy fatty acids (?-HFAs), which are highly-value derivatives of FAs. Lanolin has a high content of both ?-HFAs and FAs esters. Therefore, the aim of the project is to conjugate the production of useful and valuable chemicals with the valorization of a biomass, otherwise to be disposed of. It is to be underlined that waste wool is unavoidably joined to sheep farming and its management costs. Waste wool scouring would become profitable if further valorization of lanolin could be associated to the uses of washed low-quality coarse wools. Preliminary results of waste wool treatment and of FAs and ?-HFAs obtainment are presented.

Keratin refers to a group of insoluble proteins produced by certain epithelial cells of vertebrates, belonging to the superfamily of the intermediate filament proteins, and forming the bulk of the skin and the epidermal appendages, such as wool, hairs, nails, horns, and feathers. Keratin-based materials are tough and resistant to the natural environment and to many chemicals. Keratins are naturally biocompatible and possess cell motif-binding residues supporting cellular attachment, which is the first step in the tissue engineering replacement process. Keratins for biomedical applications have been extracted, processed, and regenerated into various forms, such as films, sponges, hydrogels, fibers, nanoparticles, microcapsules, alone or blended with other natural and manmade polymers or with bioglasses. Recent literature reports on keratin-based material have been studied for different biomedical purposes, in particular for wound healing, peripheral nerve regeneration, bone reconstruction, and drug controlled release. © 2019 Elsevier Inc. All rights reserved.

Keratin from wool fibers was extracted with different extraction methods, for example oxidation, reduction, sulfitolysis, and superheated water hydrolysis. Different samples of extracted keratin were characterized by molecular weight determination, FT-IR and NIR spectroscopy, amino acid analysis, and thermal behavior. While using oxidation, reduction, and sulfitolysis, only the cleavage of disulfide bonds takes place; keratin hydrolysis leads to the breaking of peptide bonds with the formation of low molecular weight proteins and peptides. In the FT-IR spectra of keratoses, the formation of cysteic acid appears, as well as the formation of Bunte salts (–S–SO3–) after the cleavage of disulfide bonds by sulfitolysis. The amino acid composition confirms the transformation of amino acid cystine, which is totally converted into cysteic acid following oxidative extraction and almost completely destroyed during superheated water hydrolysis. Thermal behavior shows that keratoses, which are characterized by stronger ionic interaction and higher molecular weight, are the most temperature stable keratin, while hydrolyzed wool shows a poor thermal stability.

A new and more alarming source of marine contamination has been recently identified in micro and nanosized plastic fragments. Microplastics are difficult to see with the naked eye and to biodegrade in marine environment, representing a problem since they can be ingested by plankton or other marine organisms, potentially entering the food web. An important source of microplastics appears to be through sewage contaminated by synthetic fibres from washing clothes. Since this phenomenon still lacks of a comprehensive analysis, the objective of this contribution was to investigate the role of washing processes of synthetic textiles on microplastic release. In particular, an analytical protocol was set up, based on the filtration of the washing water of synthetic fabrics and on the analysis of the filters by scanning electron microscopy. The quantification of the microfibre shedding from three different synthetic fabric types, woven polyester, knitted polyester, and woven polypropylene, during washing trials simulating domestic conditions, was achieved and statistically analysed. The highest release of microplastics was recorded for the wash of woven polyester and this phenomenon was correlated to the fabric characteristics. Moreover, the extent of microfibre release from woven polyester fabrics due to different detergents, washing parameters and industrial washes was evaluated. The number of microfibres released from a typical 5 kg wash load of polyester fabrics was estimated to be over 6,000,000 depending on the type of detergent used. The usage of a softener during washes reduces the number of microfibres released of more than 35%. The amount and size of the released microfibres confirm that they could not be totally retained by wastewater treatments plants, and potentially affect the aquatic environment.

High amounts of short fiber by-products not suitable for spinning are produced from silk manufacturing. These high protein content materials (about 94% wt) are suitable as a source of purified fibroin for biopolymer applications. An application not yet thoroughly studied is the use of fibroin solutions as a functional textile auxiliary for permanent finishing of wool garments. The aim of this work was to obtain sheath/core bicomponent fibers by coating wool fibers with thin films of silk fibroin. A polyfunctional chemical to graft fibroin onto the wool fiber surfaces without damaging the physical and chemical properties was searched to obtain wash-resistant finishing. Bifunctional as well as trifunctional epoxides were investigated. The finishing of wool with fibroin confers to the fabric innovative shine and handfeel effects, associated with an improvement of shrink resistance (antifelting) properties. The best operating conditions to obtain wool fabrics with homogeneous fibroin coating were determined.

Conducting linen fabrics were prepared by the in situ oxidative polymerization of pyrrole using ferric chloride as the oxidant and anthraquinone-2,6-disulfonic acid disodium salt as the dopant to enhance conductivity. The effect of the pyrrole concentration on the final performance and properties of the conducting fabrics was evaluated. Scanning electron microscopy and light microscopy showed a polypyrrole layer deposited on the fiber surface associated with penetration into the bulk fiber at the highest concentrations of pyrrole. Saturation of the amorphous domains of the cellulose structure and coating of the fiber surface resulted in good electrical properties, heat development by the Joule effect and reduced moisture adsorption. The mechanical properties and electrical conductivity of the fabrics were affected by the strong acid conditions of the treatment, but significant electrical properties were achieved while preserving up to 70% of the original tensile strength.

In this work five samples of fishing nets abandoned in the Venetian Lagoon were analysed to characterize them by the chemical and morphological point of view. Then, two of these nets were selected because constituted by textile filament yarns to simulate in laboratory a further consumption due to marine environment and the possible release of microplastics fragments. The nets were washed merging different textile standard methods for quality control. Then the washing effluents were collected and filtered on filters of defined microporosity. The filters were analysed with SEM and a statistical counting was performed.

Until today, many studies (Hidalgo-Ruz and Gutow et al. in Environ SciTechnol 46:3060–3075, 2012; Auta et al. in Environ Int 102:165–176, 2017) were focused on the origin or the formation mechanisms of microplastics. Microplastics comprise a very heterogeneous group of fragments that vary in size, shape, color, specific density, chemical composition, and other characteristics.

The substances responsible for the yellowing of wool treated with nitric acid are two amino acid constituents of the fibre: tryptophan and tyrosine. Nitric acid penetrates the fibres and carries out electrophilic aromatic substitution on the two above-mentioned amino acid residues, producing different colour yields. The intensity of yellowing depends in various ways on the treatment conditions (time, temperature, nitric acid concentration, agitation, and liquor ratio). Yellowing evaluation shows abnormal yellowing depending on acid concentration in the range 5.6-5.9 M. Working in this region makes it possible to use the chromatic reaction in order to show the damage done to wool fibres by the oxidising agents utilised in normal antifelting treatments. Wool damage by the oxidants is usually evaluated by dyeing methods based on different affinity of damaged fibres. By contrast, the xanthoproteic reaction yields chromogens as a function of the accessibility of tryptophan and tyrosine residues for the action of nitric acid on damaged fibres, and can be used for assessing the degree of antifelting treatment and its possible unevenness through the development on the treated wool of a yellow coloration more intense than on untreated wool.

Keratin extracted from wool by sulphitolysis, up to a content of 15 wt/wt% was used as a natural reinforcing agent for cross-linked polymers obtained by photopolymerization of thiol-ene systems. The keratin-based photocured coatings obtained show significant improvement in terms of thermal stability, crosslinking density, Tg values and mechanical properties. Moreover, a clear increase of the biodegradability of the starting thiol-ene polymer matrix was induced by the presence of the keratin biopolymer as reinforcement. © 2014 Elsevier B.V.

Polypropylene (PP)-based composites containing 20 wt.% wool fibres were successfully prepared using a simple melt blending procedure. A blend of a commercial-grade PP and a maleinised PP was chosen as the matrix. To investigate the effects of modifying the fibre surface on the fibre/matrix adhesion, wool fibres were used as received, oxidised, or functionalised with a silane-based coupling agent, capable in principle of reacting with both the fibres and the polyolefinic matrix. The silanisation of the fibres and the consequent surface modifications were assessed using infrared spectroscopy and scanning electron microscopy. The resulting PP-based composites were thoroughly characterised in terms of their morphology, thermal stability and mechanical behaviour.

Natural fibres by products represent sustainable and locally available raw materials for application in bio architecture. These materials, which are renewable, abundant, cheap and lightweight, may replace man-made synthetic or artificial insulating materials (extruded polystyrene, glass wool and rock wool) which are more energy demanding. They are easy recyclable and carbon dioxide neutral, i.e. they do not return excess carbon dioxide into the atmosphere when they are composted at the end of the life cycle. Natural fibres display good thermal-insulating, sound-proofing and mechanical properties. They also enable better handling and working conditions in processing and laying regarding dermal and respiratory irritation, and show less concern with safety and health as for end use properties. Moreover, their thermal-moisture behavior is close to the human body demands (they enhance and stabilize indoor humidity microclimate) and they may contribute to reduce the sick building syndrome due to airborne VOCs (Volatile Organic Compounds) in existing and new constructions. This work was focused on the preparation of biocomposite stiff boards entirely made with natural fibres, exploiting the different properties of protein and cellulose components submitted to mild alkali treatments. Waste wool was used in combination with rice straw. Thermal properties were determined on testing specimens of insulation boards. Wool-rice straw based insulating materials show very good thermal insulating properties (thermal conductivity is around 0.04 W/m °K and it depends on bulk density and fibre proportion). Important expected advantages are accessibility of raw materials from the long-term point of view, which is very important for sustainable development. Developed materials can be used in existing and new buildings, for insulation of inclined roofs, hung ceilings, partition walls and external claddings (integrated thermal insulation). Potential applications can also be envisaged in other fields, such as the automotive sector where recyclability and fire resistance are fundamental requirements.

The purpose of this work is to understand the impact of superheated water hydrolysis treatment on the chemical properties of wool, and compare it with a conventional method of alkaline hydrolysis. The effects of hydrolysis temperature and concentration of alkali on the properties of wool were investigated. Superheated water hydrolysis was carried out at the temperatures of 140℃ and 170℃, with a material to liquor ratio of 1:3 for 1 hour. In conventional alkaline hydrolysis, the experiments were carried out in the same conditions using potassium hydroxide (KOH) and calcium oxide (CaO) with a concentration in the range of 5%–15% on the fiber weight (o.w.f.). The effects of hydrolysis temperature and alkali concentrations on wool properties were checked using optical and scanning electron microscopy. It was observed that the hydrolyzates obtained in both cases contained low molecular weight proteins and amino acids. Both the hydrolysis processes resulted in degradation of the wool fibers. However, superheated steam hydrolysis is an environmentally friendly and less expensive process, as it is performed using water as a solvent. The wool hydrolyzates produced using superheated water hydrolysis could find a potential application in agriculture, such as fertilization, soil improvement and suchlike.

The aim of this work is to improve the select mechanical properties of keratin films for biomedical application by exploiting the hierarchical cell structure of wool fibers in a simple and green process. Bio-composite keratin films were prepared by ultrasonic irradiation of wool fibers soaked in clean water, have previously been swollen in mild alkali. The disruption of the fiber cell structure produced a suspension of cortical cells that was centrifuged and rinsed to remove part of the hydrolyzed keratin matrix, then cast into micro-structured porous films made of randomly oriented cortical cells stuck to each other by solidification of the matrix. The chemical and physical properties of the porous films were compared with those of compact films produced using the entire hydrolyzed keratin matrix. Reduction of the keratin matrix amount leads to an even micro-porous structure and improves the mechanical properties (ultimate tensile strength: 11.36 MPa; elongation at break: 3.18%), the moisture uptake and the thermal stability of the films. These properties, associated with other properties of wool keratin, which is naturally hydrophilic, non-burning, biodegradable and biocompatible, make the porous bio-composite keratin films simple and low-cost candidates for biomedical and biotechnology applications.

In this study, nanofibre mats for chemical adsorption of heavy metals were prepared by electrospinning blends of hydrolyzed keratin (HK) and polyamide 6 (PA6) in formic acid. Viscosity measurements of the spinning solutions and morphological analyses of the fracture sections of the same polymer blends cast into films, suggested intermolecular interactions and good compatibility between HK and PA6. The mats made of continuous randomly oriented blend nanofilaments of HK/PA6 50/50 wt, with a mean diameter of about 200 nm, were tested as chromium (VI) ion adsorbents. The parameters investigated included initial chromium ion concentration, pH, contact time and adsorbent dosage. The maximum adsorption capacity occurred at acidic pH. The pseudo-first order, the pseudo-second order and the intraparticle diffusion models were used to describe the kinetics of adsorption process. It was found that kinetic data fit the pseudo-second order model and follow the intraparticle diffusion model, although diffusion is not the only rate control step. Adsorption data fit well the Freundlich isotherm model and the maximum adsorption capacity was found 55.9 mg/g. Moreover, the mean free energy (E) of adsorption ranges between 8 and 16 kJ/mol, so that the adsorption mechanism for HK-based nanofibres was explained as an ion-exchange process.

In recent years, there has been growing attention on intrinsically conducting polymers, such as polypyrrole (PPy) because of the wide range of possible applications. Adhesion to other materials is a pending problem that could be tackled by enhancing the chemical affinity of the surface toward PPy coating. In this work, low-temperature plasma pretreatments were used for improving adhesion of PPy on polyester (PET) fabrics by changing the surface chemistry and generating a microscopically rough surface. Oxygen and argon plasmas were used to treat both sides of PET fabrics before PPy deposition by in situ chemical polymerization. Moreover, PPy depositions were performed 1 h, 1 week, and 1 month after the plasma treatments to study possible ageing effects. Different chemical/physical characterizations (contact angle, surface energy, atomic force microscopy, and X-ray photoelectron spectroscopy) showed the efficacy of plasma pretreatments in inducing wettability on PET fabrics and promoting adhesion of the PPy layer. The enhanced adhesion was confirmed by abrasion tests and subsequent surface resistivity and color measurements. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

A new approach to the objective identification of the different animal hair fibres based on the application of monoclonal antibodies has been discussed. Three different extraction methods including metabisulphite/urea, dithiothreitol/urea, thiourea/urea/dithiothreitol were compared to evaluate efficiency and repeatability in extracting keratin from wool and cashmere fibres. ‘Anti-cashmere’ monoclonal antibodies were produced by immunization of mice with Type II intermediate filament proteins extracted from cashmere, purified by 2D preparative electrophoresis. Two monoclonal antibodies (named P21 and I6) were tested with both wool and cashmere blends for both qualitative and quantitative analysis. The interaction of P21 and I6 antibodies was studied by the immunoblot method. After a calibration carried out on both the antibodies, the method was applied to unknown wool/cashmere blends and compared with the results of the analysis carried out by the SEM (scanning electron microscopy) method IWTO 58-00 in order to preliminarily assess the method.

Mats of randomly oriented nanosized filaments, prepared by electrospinning wool keratin/polyamide 6 blends in formic acid, were evaluated as adsorbents of Cu 2+ ions. The adsorption capacity was evaluated as a function of the nanofibre composition, specific surface area, initial metal ion concentration, contact time and pH of the solution. The adsorption tests revealed that keratin-based nanofibres highly adsorb Cu 2+ ions and the adsorption capacity increases with increasing the specific surface area of the nanofibre mats. The maximum adsorption capacities for nanofibre mats containing 50%, 70% and 90% (wt.%) of keratin were found to be 61.7 (mg/g), 90 (mg/g) and 103.5 (mg/g), respectively. The Cu 2+ adsorption onto the keratin rich nanofibres is highly pH-dependent and the optimum pH was found above the isoelectric point of keratin. The experimental data fit the pseudo second-order kinetic model. Infrared analysis demonstrated the formation of complexes between Cu 2+ ions and keratin that involve terminal free carboxyl groups of the protein.

Wool and hair can be regarded as bio-composite keratin-based fibres made up of spindle shaped cortical cells oriented along the fibre, embedded in an amorphous protein matrix. This natural composite structure has been exploited to prepare cheap and easy keratin-based films. Wool was submitted to alkali treatment, rinse, and ultrasonic disruption of its hierarchic assembly, obtaining a suspension of cortical cells in a protein aqueous solution that was transformed into films by cold casting. Preliminary investigation showed the bio-composite nature of the films, with randomly oriented cortical cells embedded in the protein matrix. Structural characterization revealed the presence of predominantly -sheet secondary structure due to lanthionine and lysino-alanine covalent cross-links. Bio-composite keratin films are transparent and show good tensile strength and thermal stability, high moisture regain and swelling, but are fragile in ambient condition like films of reduced keratin reported in literature. Further characterization and improvement should candidate bio-composite keratin films from wool fibrillation as easy and cheap materials for biotechnology applications.

Electrospinning is a simple and versatile process for producing small-diameter fibres (nanofibres). However, in spite of the many potential applications of electrospun nanofibres, further process developments are still necessary to achieve a decisive productivity breakthrough for electrospinning plants. Increasing knowledge of multi-jet electrospinning is crucial for developing industrial devices for large-scale nanofibre production. This paper reports on the effect of a non-conducting textile substrate placed between a jet-emitting source (nine-nozzle arrangement) and collector. Shielding the electric field changes the electrospinning conditions, nanofibre morphology, stability of jets and fibre deposition on the collecting surface. Various perturbation phenomena of the electrically driven jets were recorded and are described. The intensity of the perturbations increases as the weight of the non-woven substrate increases resulting in defects in the nanofibrous mat (i.e. beaded nanofibres), production of tick fibres or failure to produce fibrous materials (e.g. films, droplets). The paper also reports an objective image-processing procedure to enhance the evaluation of the collector after nanofibre deposition. Copyright © 2010 Society of Chemical Industry

The extra-fine, soft and warm fibres used by the textile industry for manufacturing high-quality, luxury textiles are obtained from the undercoat hair of several domestic mammals of the genera Capra, Bos, Camelus, and Lama. The demand for ‘speciality fibres’ by the fashion world represents an important opportunity for livelihoods, on condition that conservation of the wild species is preserved. Large scale trade of hair from wild goats hunted for meat or trophy and hybridisation of wild (Capra ibex) and domestic (Capra hircus) goats or wild Vicuna (Lama vicugna) and domestic Alpaca (Lama pacos), with the aim of improving fibre fineness and yield, would involve a risk of genetic pollution and would severely threaten conservation and biodiversity. This work describes fibre morphology and cell structure of fine fibres from the most important wild and domestic fibre producing species with the aim of enhancing traits for identification purposes. Microscopy investigation shows that exposure to thermal and nutritional stresses in the wild, lead to finer hair associated with lower rate of growth, yielding orientation and elongation of the cuticle cells. Differential scanning calorimetry reveals specie-specific differences in the internal structure of the fibre cortex, probably related to the process of hair keratinisation.

Solvent-based preliminary treatments were carried out on polyamide fabrics to be coated with a thin layer of electrically conducting doped polypyrrole, with the aim of improving the adhesion of the conducting layer to the fibre substrate. Polyamide fabrics were treated with dilute formic acid, pure tetrachloroethylene and ethanol/water at different temperatures and times. After the treatments, the fabrics were coated with polypyrrole by in situ chemical oxidative polymerisation.The adhesion of the PPy layer was evaluated by means of surface resistivity measurements, SEM investigation and ATR FT-IR analysis after Martindale abrasion tests. The adhesion of PPy layer on the fibre surface was strongly improved by the solvent treatments, in particular with ethanol and tetrachloroethylene. The surface resistivity of the ethanol-treated fabrics did not change after more than 200 abrasion cycles and the PPy layer linked to the fibre surface was observed by SEM and AIR FT-IR also after 4000 abrasion cycles. (C) 2010 Elsevier B.V. All rights reserved.

Large amount of protein wastes, such as fibre by-products from the wool textile industry and poor quality wools from stock-farming and butchery, are currently disposed of. Their pooling and processing would allow the production of innovative bio-plastics suitable for novel large-scale uses (compostable films for agriculture and packaging, filaments for textiles, sanitation and filtration). Since it is known that keratinous materials can absorb toxic substances such as heavy-metal ions, formaldehyde and other hazardous VOCs (volatile organic compounds), applications can also be envisaged in water purification and air cleaning. However, the poor mechanical properties of keratin regenerated from wool restrict processing and practical applications. Therefore, blending keratin with appropriate polymers with better structural properties is a way to overcome the aforementioned problems. In the present work, keratin was extracted from wool and blended with polyamide 6 in formic acid as the common solvent, in order to obtain blend solutions suitable for nanofibre production by electrospinning. Viscosity of the blend solutions decreased with increasing the keratin content, while electrical conductivity (of 2 mS/cm) did not change significantly. Electrospinning produced very thin nanofibres, in the range from 70 to 300 nm, with mean diameter of about 150 nm. The adsorption of heavy metal ions from water was evaluated by immersion of keratin/PA6 nanofibre mats in an aqueous solution of Cr(3+) and compared with the films obtained by casting from the same solution. For the nanofibre non-wovens the adsorption capacity slightly increased with increasing the keratin content. That of the nanofibre mats was at least one order of magnitude greater than the films obtained by casting. Moreover, whilst the physical efficiency of nanofibre-based filters is well known, the formaldehyde adsorption of protein nanofibres was studied in order to test their suitability for application in "chemical" air cleaning.

Antistatic treatments lower the electrical resistivity of textiles and facilitate charge dissipation avoiding high potential electrical discharges. Moreover, low surface resistivity gives textiles electro-conducting, soil release, thermal and electromagnetic shielding properties. A new way of producing electrically conducting textiles consists of treatments with organic conducting polymers. Unfortunately, conducting polymers have a low level of processability because of their poor mechanical and physical properties. These problems have been overcome by simple in situ depositions of conducting polymers on different substrates in order to produce composite materials with good mechanical properties. Polypyrrole (PPy) is one of the most promising candidates because it exhibits high conductivity and good environmental stability. In situ PPy synthesis on wool and on other animal fibers is presented in this work. A preliminary oxidative treatment (e.g. shrink-proofing, bleaching or depigmentation) improves the electrical properties of the resulting conductive composite textiles significantly.

Keratin proteins are the major component of hair, feathers, wool and horns and represent an important source of renewable raw materials for many applications. Regenerated keratin has useful properties such as biocompatibility and biodegradability. Moreover, keratin materials can absorb heavy metal ions, formaldehyde and other VOCs. In this work, regenerated keratin was blended with aqueous solutions of poly(ethylene oxide) (PEO) in different proportion in order to improve its processability. Keratin/PEO nanofibres were produced by electrospinning the blend aqueous solutions. The chemical, physical and rheological characteristics of the blend solutions were correlated with morphology, structural, thermal and mechanical properties of the electrospun mats.

A large amount of coarse wool, practically unserviceable for textile use, is generated in Europe from sheep shearing and butchery. Such a byproduct is either dumped, burned, or sent to landfill. Following the European Commission regulations on animal byproduct control, unserviceable raw wool is classified as a category 3 special waste materials. The collection, storage, transport, treatment, use, and disposal of such unserviceable raw wool are subject to European Union regulations because of a potential risk to human and animal health. This study aims at converting the waste wool into nitrogen fertilizers at a commercial scale for grassland management and cultivation purposes. The chemical transformation of waste wool in to fertilizer is based on a green economically sustainable hydrolysis treatment using superheated water. The experiments were carried out in a semi-industrial reactor feeding superheated water. The wool/superheated water system was maintained for different reaction times. The optimal conditions for this treatment were as follows: 170 °C for 60 min with a solid to liquor ratio (MLR) close to 1. The hydrolyzed product was analyzed using amino acid analysis and molecular weight distribution. Both the amino acid and molecular weight distribution analysis revealed that the wool was completely degraded and the hydrolyzed product contains a low molecular weight proteins and amino acids. Several hydrolyzed product obtained at different conditions were tested for germination which showed a germination index higher than 100% without collateral phytotoxicity. The presence of amino acids, primary nutrients, and micronutrients in wool hydrolyzates, along with a concentration of heavy metals below the standard limit, confirm the possibility of using wool hydrolyzates as a nitrogen based ecologically sound fertilizer.

Submicron size fibers (so-called nanofibers) are easily produced with an electrospinning apparatus from polymer solutions of poly(ethylene oxide), poly(vinyl alcohol), and polyamide-6. Electrospinning seems the most powerful tool for fabricating polymer nanofibers. Fibers were directly deposited in the form of random fiber webs with high area-to-volume ratio and small porous size on ordinary nonwoven filters of PET microfibers. Morphology and diameter distribution of the electrospun filaments were characterized by SEM investigations. The flow resistance of the produced composite filters are evaluated by means of air permeability measurements. The electrospun fibers have diameters ranging from about 70—500 nm and are interconnected each other to form thin webs that have very small pore size. After the electrospinning treatment, the air permeability of the filter media decreases 6—17 times showing a significant change of flow resistance that can be controlled by the thickness of nanofibers layer and the pore size. High efficiency nano-microfibers composite filters could be used in a wide range of applications, ranging from air cleaning for automotive to environment conditioning or liquid filtration.

Anti-felting properties of knitted wool fabrics treated with chitosan were investigated, by both a laboratory scale treatment and a semi-industrial application. The influence of oxidative wool pre-treatments was analysed. The distribution of chitosan on treated wool fibres was also assessed using both qualitative and quantitative evaluation methods. The study provided shrinkage data perfectly comparable with those obtained by the currently used shrinkproofing processes, but with two important advantages: the total absence of chlorine in the process and the complete biodegradability of chitosan. The semi-industrial treatment showed the complete reproducibility of the laboratory scale results, giving rise to the possibility of an industrial adaptation of the process.

A wool fiber sample was submitted to chemical-free steam explosion in view of potential exploitation of keratin-based industrial and farm wastes. Fiber keratin was converted into a dark-yellow sludge that was submitted to phase separation by filtration, centrifugation, and precipitation of the soluble materials from the supernatant liquid. The resulting products, when compared with the original wool, showed the extent of disruption of the histology structure, reduction of the molecular weight to water-soluble peptides and free amino acids, and change of the structure of the remainder of the protein associated with breaking of disulfide bonds and decomposition of the high-sulfur-content protein fraction.

Coating the fibre surface by in situ oxidative chemical polymerisation of polypyrrole (using FeCl(3) as oxidant) is a readily industrial applicable way to give electrical properties to wool with good ageing stability [1], although pre-treatments are required to avoid damage of the cuticle surface due to the acidic condition of the process. FT-IR and EDX analysis reveal that organic sulphonates and sulphates, used as dopants, are absorbed by wool, while chlorine ions are preferably embedded on the polypyrrole layer. The resulting electrical conductivity seems mainly due to the presence of chlorine as counter-ion of polypyrrole; nevertheless, the presence of arylsulphonate in the polymerisation bath increases the electrical conductivity of the coating layer.

Conducting textiles were prepared embedding polypyrrole in natural and man made cellulose-based fibres, such as cotton, viscose, cupro and lyocell, by means of in situ polymerisation. Chemical vapour phase deposition of polypyrrole is a suitable process for producing electro-conductive composites in two steps: (a) fabric impregnation with an aqueous solution of oxidant and dopant and subsequent drying; (b) exposition to pyrrole vapour and polymerisation. Comparative morphological and structural analysis was carried out on the conducting viscose prepared with both vapour and liquid phases processes and some significant differences in the structural, calorimetric and electrical properties were highlighted, due to the different methods of preparation. Vapour phase prepared fabrics show a high uniform polypyrrole coating on the fibre surface and its partial penetration inside the amorphous zones of the fibre bulk. WAXD analysis shows that the conducting fabrics preserve the crystalline structure of the cellulose matrix, while SAXS results evidence the presence of a nanoparticle dispersion of polypyrrole in the cellulose matrix. Polypyrrole–cellulose conducting composite textiles show good performances to light exposure and washing fastness tests.

The chemical polymerization of pyrrole was studied with the aim of defining the best operating conditions for obtaining conductive fabrics of synthetic fibers. Ammonium persulfate was chosen as the oxidant, and various dopants were tested. Among these, naphtalene-2,6-disulfonic acid disodium salt enabled the lowest surface resistivity to be reached. Hence, several kinetic runs were performed to explain the influence of some operating conditions as oxidant concentration and temperature. A pseudo-first-order kinetic equation was derived, and the reaction rates were found to be practically unaffected by the presence of the textile substrate. Pyrrole polymerization was faster than adsorption of the monomer, suggesting the hypothesis of fast polymerization outside the fibers followed by adsorption onto the fiber surface. The surface coating of polypyrrole was evidenced by microscopic observation of the fiber cross sections. ©2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4121–4126, 2006

Type II keratins from cashmere are used as antigens to produce species-specific monoclonal antibodies for fiber identification purposes. Balb/c mice are immunized with the keratins purified by two-dimensional preparative gel electrophoresis. Hybridoma clones showing high immunological responses are subcloned by limiting dilution and then expanded to obtain antibodies in large amounts. When the antibodies are screened by two-dimensional immunoblotting for immunoreactivity with keratins isolated from cash mere and wool, several differences are detected, both quantitative and qualitative. Al though further work is needed to develop routine analytical protocols, the preliminary results reported in this paper appear to be extremely promising, and our approach could contribute to solving the problem of the objective identification of cashmere and other speciality animal fibers.

In the wool textile industry, several processes serve to improve the commercial properties of the fibres such as fineness, softness, length, strength and lustrous. For example, wool is chemically treated with reductive agents then stretched and set. This leads to modifications of the original protein structure causing changes in thermal behaviour, dyeing, colouristic and wet resistance properties. A multidisciplinary approach was used to investigate treated and untreated wools, with the aim of exploiting the nature of the structural changes. SEM and TEM revealed changes on the cuticle and cortical cell morphology; structure modification were studied by FT-IR and DSC.

Management of waste wool is a problem related to sheep farming and butchery in Europe. Since the primary role of European flock is meat production, sheep are crossbreds not graded for fine wool production. Their wool is very coarse and contains a lot of kemps (dead fibres), so that it is practically unserviceable for textile uses, and represents a by-product which is mostly disposed off. Green hydrolysis using superheated water is an emerging technology to turn waste wool into amendment-fertilizers for the management of grasslands and other cultivation purposes. In this way wool keratin (the wool protein) is degraded into simpler compounds, tailoring the release speed of nutrients to plants. Wool, when added to the soil, increases the yield of grass grown, absorbs and retains moisture very effectively and reduces run off of contaminants such as pesticides. Moreover, the closed-loop cycle grass–wool–grass is an efficient form of recycling, because the wool-grass step is solar powered and grazing sheep increases soil carbon sequestration on grasslands and fertilisation, if not over-used, can enhance the carbon sequestration rate. Economical results of using hydrolysed wool as a fertilizer are expected from the increase of the management yield and the extension of the pasture lands that may contribute to employment and profit of sheep farming, increase European sheep population, and reduce European dependency of imported meat which is forecast to rise in the next years.

The fine undercoat fibers removed from wild goats hunted for meat and trophy, principally belonging to subspecies of Capra ibex, are used as an alternative to Shatoosh, the hair of the endangered Tibetan antelope (Pantholops hodgsonii). Although currently legal, the large-scale use of these fibers (known as "Yangir"), and hybridization of ibex with domestic goats to improve fiber fineness and yield, would severely threaten the conservation of wild ibex. A SEM investigation shows morphological differences in the cuticle cell patterns of fine fibers from the domestic Cashmere goat, the wild Yangir goat, and the Tibetan antelope. A study of the DSC traces reveals differences in the enthalpy of denaturation of the crystallites. This information enables identification of these fibers, including those from lots submitted to dehairing processes, such as are commonly found in the animal fiber trade.

Thermal degradation of modern and ancient linen fabrics was investigated by DSC and FTIR analysis in order to find a possible correlation between thermal behaviour and the age of linen. A similar p...

The European Union (EU) area has the second largest world sheep population, numbered to about 87 millions (Source EU-Eurostat 2014). The EU flock is made of crossbred sheep not graded for fine wool production. The annual wool clip amounts to about 200 000 t and its management is a specific problem for the EU livestock sector. Indeed, wool from sheep farming and butchery industry is very coarse and contains a lot of kemps (dead fibres), making it practically unserviceable for the textile industry. Unserviceable wool is mostly disposed in landfills or illegally thrown over. Thus, shearing, storage, transportation and disposal of waste wool in accordance with current EU Regulation, heavily weigh on the profit of sheep farming. The Life+ 12 ENV/IT000439 GreenWoolf project aims at converting waste wool into nitrogen fertilizers at a commercial scale for grassland management and organic agriculture purposes. The chemical transformation is based on a green economically sustainable hydrolysis treatment using superheated water. The experiments were carried out in a semi-industrial reactor feeding superheated water and, due to condensation, the wool/superheated water system was maintained for different reaction times. The optimal conditions for this treatment were: 170 oC for 60 min with a solid to liquor ratio close to 1. Chemical analyses such as amino acid analysis and molecular weight distribution performed on the hydrolysis products obtained revealed that the wool was completely degraded, the reaction product containing low molecular weight proteins and amino acids. Several product batches tested for germination showed an index higher than 100% without collateral phytotoxicity. The presence of amino acids, primary nutrients and micronutrients in wool hydrolyzates, along with a concentration of heavy metals below the standard limit, confirms the possibility of using wool hydrolyzates as nitrogen based ecologically sound fertilizer suitable for organic agriculture.