Keratins extracted from Merino wool and Brown Alpaca fibres as potential fillers for PLLA-based biocomposites

This paper reports on the promising perspectives of using keratins extracted by sulphitolysis reaction from Merino wool (KM) and Brown Alpaca fibres (KA) in poly (l-lactide) (PLLA)-based biomaterials. Both types of keratin were dispersed in chloroform (CHCl3) and tetrahydrofuran (THF), and optimisation of dispersion methods and parameters using the two selected solvents was considered. The extraction yield, as well as supermolecular structures, morphology and thermal behaviour of the two proteins before and after the regeneration in CHCl3 was investigated. The results indicated that the supermolecular structures and thermal behaviour of the two proteins were affected by the interaction with CHCl3, producing decrease of the amount of α-helix structures in KM and an increase for KA, a slight decrease of β-sheet structures and a reduced thermal stability of α-crystallites for both keratins. Biocomposite films based on PLLA polymer matrix and two different contents of Merino wool and Brown Alpaca keratins (1 % and 5 % wt) were successfully developed by solvent casting in chloroform and the resulting morphologies after incorporation of different keratins (as a function of content and source) give evidence of different surface topographies, with a random distribution of keratin in flask-like structure. PLLA/5KA and PLLA/5KM samples with 1 % and 5 % wt of keratins show a specific pore-like surface microstructure, induced by solvent evaporation.Peer Reviewe

Multifunctional finishing of wool fabrics by chitosan UV-grafting: An approach

The aim of this study was the surface modification of wool fibers to confer a multifunctional finishing to the fabrics, improving the textile value and its applications without damage of comfort properties. The attention was focused on an economical and environmental friendly process to obtain an effective treatment with good durability to washing. Chitosan in acetic acid solution was applied by padding, and grafted by ultraviolet radiation, through radical reactions promoted by a photoinitiator. 2% chitosan grafted was enough to confer satisfactory antimicrobial activity (67% reduction of Escherichia coli) after an oxidative wool pre-treatment and 1 h impregnation at 50 ◦C. Moreover treated wool fabrics showed a strong dyeability increase toward acid dye. However the evaluation of the treatment durability to laundering showed different behavior depending on the nature of the surfactants. Finally, anti-felting properties with respect to untreated fabrics were revealed, while no effect was shown toward anti-pilling properties

Multifunctional Finishing ofF Wool Fabrics by Chitosan UV-grafting

Chitosan was grafted on wool knitted fabrics, by ultraviolet radiation, in order to confer peculiar properties increasing the textile value and its applications. Results showed first of all the antimicrobial properties conferred by the treatment. Chitosan weight on was optimized while an oxidative pre-treatment of the wool as well as the impregnation method were investigated to improve the effectiveness of treated fabrics. Moreover treated wool fabrics showed an increased dyeability towards acid dyes and antifelting properties with respect to untreated fabrics, while no effect was revealed toward antipilling propertie

Multifunctional Finishing of Wool Fabrics by Chitosan UV-grafting

Chitosan was grafted on wool knitted fabrics, by ultraviolet radiation, in order to confer peculiar properties increasing the textile value and its applications. Results showed first of all the antimicrobial properties conferred by the treatment. Chitosan weight on was optimized while an oxidative pre-treatment of the wool as well as the impregnation method were investigated to improve the effectiveness of treated fabrics. Moreover treated wool fabrics showed an increased dyeability towards acid dyes and antifelting properties with respect to untreated fabrics, while no effect was revealed toward antipilling properties

Thermal properties of wool fabrics treated in an Atmospheric Pressure Post-Discharge plasma equipment

A plain-weave wool fabric has been treated in a roll-to-roll atmospheric pressure, post-discharge plasma equipment at three fabric speeds. The thermal properties of the treated fabric have been investigated by means of an Alambeta instrument. The thermal resistance and thermal diffusivity increased after the plasma treatment while the thermal absorptivity and volumetric heat capacity decreased. The longer the plasma-to-fabric exposure time, the more marked the change in the fabric's thermal properties. Since thermal conductivity was unaffected after the treatment, the thermal properties changed due to the increase in thickness that was observed after the plasma treatment. A validated model has been used to predict the human psychophysical perception of the fabric hand. As a consequence of the more voluminous structure, a softer and warmer hand has been predicted for the treated fabrics compared to the untreated ones

Study of Methylene Blue adsorption on keratin nanofibrous membranes

: In this work, keratin nanofibrous membranes (mean diameter of about 220nm) were prepared by electrospinning and tested as adsorbents for Methylene Blue through batch adsorption tests. The adsorption capacity of the membranes was evaluated as a function of initial dye concentration, pH, adsorbent dosage, time and temperature. The adsorption capacity increased with increasing the initial dye concentration and pH, while it decreased with increasing the adsorbent dosage and temperature, indicating an exothermic process. The adsorption results indicated that the Langmuir isotherm fitted the experimental data better than the Freundlich and Temkin isotherm models. A mean free energy evaluated through the Dubinin-Radushkevich model of about 16kJmol(-1), indicated a chemisorption process which occurred by ion exchange. The kinetic data were found to fit the pseudo-second-order model better than the pseudo-first-order model. The obtained results suggest that keratin nanofibrous membranes could be promising candidates as dye adsorption filters