Cotton fibres with fine glass flakes (CFGF), a new solid matrix, is reported here for soaking and retaining more electrolyte and water that aids to enhance proton conductivity above that of ...conventional glass mat-phosphoric acid electrolyte. Further, layering of all inorganic gel paste (GP) electrolytes on CFGF reduces the charge transport resistance, Warburg impedance and diffusion time, and enhances the proton conductivity. The use of sandwiched GP-CFGF-GP hybrid electrolyte in fuel cell offers higher power density, durability and higher allowable operating temperature up to 180 °C.
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Short fibre based cotton flocks from end-of-life jeans fabric (denim twill weave) were introduced in an amount of 16 wt.% in a polypropylene (PP) matrix using a specifically designed manufacturing ...process to preserve as much as possible the properties of the cotton waste during injection moulding. This involved a first phase of binding the cotton flocks on polyvinyl acetate (PVAc) support, then pelletizing them with PP and finally extruding the final composite. The resulting composites were subjected to morphological, tensile and fatigue characterisation with stress levels from 50 to 90% of ultimate tensile strength. Results indicated that injection moulding offered a sufficient uniformity of properties to the composite, albeit with some occurrence of pull-out during loading. In particular, the tensile performance exceeded that of the pure matrix in a measure compatible with the amount of fibres introduced. In addition, tensile fatigue loading up to 5000 cycles evidenced a limited amount of degradation for maximum applied stresses up to 70% of composite tensile strength.
The present study emphasizes appending the knowledge of structure-property relations, elasto-mechanical properties. The knowledge of the elasto-mechanical properties of cotton fibers plays a ...significant role in industrial applications, these properties determine the fabric stiffness, hardness, and tailorability of cotton. For various cotton samples studied here, whose molecular orientations were unknown, and few studies are reported to study its basic structural properties. However, the linked atom least square fit (LALS) and crystallographic tool PLATON has been utilized to obtain the crystal structure of LRA and Shankar cotton fibers using XRD data. The elastic constant matrix for the monoclinic unit cell with the lattice parameters a = 7.350 Å, b = 8.220 Å and c = 10.370 Å and γ = 96.28° has been obtained by considering Treloar's assumptions. These elastic constants are incorporated to the ELATE tensor analysis tool along with the Voigt principle to evaluate elastic moduli. It is observed that the spatial variations of these elastic moduli deviate from the spherical shape, which shows the existence of the anisotropic property of the fibers. With all these structures and physicomechanical parameters analyzed for the cotton samples studied, the structure-property dependencies have been obtained utilizing the functional data analysis technique.
An alkali based method has been optimised and proposed to extract the cellulosic fibres from the corn husks. Physicochemical and morphological properties of the fibres extracted from corn husk have ...been studied in detail, and compared with the well-explored cellulosic fibre, like cotton and ligno-cellulosic fibre, like jute. Scanning electron microscopy and energy dispersive X-ray were used to study the surface and cross-sectional morphology and the elemental analysis of the corn-husk fibres and compared with cotton and jute fibres. The analysis showed that the morphological and the physico-chemical properties of the extracted corn husk fibres are comparable with ligno-cellulosic jute fibre. Also, improvement in thermal stability of corn husk fibre was obtained by application of the agro-waste banana pseudostem sap (BPS). BPS treated corn husk fibre showed the limiting oxygen index (LOI) value of 32 against the LOI value of 21 for the control corn fibre. In vertical burning test BPS treated corn yarn showed self extinguishing behaviour and 50 mm char length whereas control corn yarn was burnt within 1 min with flame and afterglow. TG analysis of the BPS treated corn yarn showed more than 30% weight retention at 450 °C compared to the 20% weight retention of the control corn yarn at the said temperature. In addition, major mass loss peak in TG curve has been shifted from 350 to 300 °C after BPS treatment (signature of the dehydration effect of the treated corn yarn). The flame retardant treatment process is comparatively simple and cost-effective, as add-on remains only at 8% and the BPS is available in large quantity in many countries.
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In this work, nanofibrillated cellulose (NFC) has been evaluated as a potential reinforcement for cement mortar composites. Two types of vegetable fibres with different composition and properties ...(cellulose content and microfibrillar angle), sisal, and cotton linters pulps, were initially characterised in order to assess their reinforcing capability. Sisal pulp was found to be most suitable as reinforcement for the brittle cementitious matrix. Nanofibrillated cellulose was produced by the application of a high intensity refining process of the sisal pulp. It was found that 6 hours of refining time was required to obtain the desired nanofibrillation of the fibers. Cement mortar composites reinforced with both the sisal fibres and the nanofibrillated cellulose were prepared, and the mechanical properties were determined under flexural tests. The cement mortar composites reinforced with the nanofibrillated cellulose exhibited enhanced flexural properties, but lower values of fracture energy, than the ones reinforced with the conventional sisal fibres.
Nanofibrils of cellulose were prepared from short staple cotton by refining process using a lab disc refiner that exerts a combination of shear and frictional forces. The nanofibrils were ...characterized by scanning electron microscope (SEM), atomic force microscope (AFM), X-ray diffractometer (XRD) and Fourier transform infrared spectroscopy (FTIR). From SEM and AFM, it was found that starting average diameter of the cotton fiber (∼25 µm) was reduced to 242 nm after 30 passes of refining. FTIR analysis revealed the increase in amorphous nature of cotton cellulose due to refining process. Supportively, XRD analysis showed a steady decline in percent crystallinity of the cotton fibers as the cotton fibres were passed through the refiner for more number of passes. Similarly, degree of polymerization (DP) was reduced from 2720 to 740 due to the refining process. Nanofibrils of cellulose from short staple cotton have a huge potential for application in nanofilters and as biodegradable fillers in nanocomposites.
The purpose of this work was to assess the usefulness of thin layer chromatography (TLC) for discriminating single cotton fibres dyed with red reactive dyes. An effective enzymatic extraction ...procedure with the use of cellulase for the red reactively-dyed cotton fibres was developed and used for the discrimination of fibres derived from 21 garments purchased commercially. Discrimination of the fibres relied on the separation of the extracted dyes by thin layer chromatography (TLC). Four eluents were used to develop the plates with the extracted dyes, and the obtained results were analysed using, among others, video spectral comparator (VSC). Observation of TLC plates in visible, ultraviolet and infrared light allowed unambiguous discrimination of 5 and probable discrimination of 6 of the 21 fibres tested. The remaining fibres were divided into several groups. Comparison of the acquired results with those obtained for the same examination material by standard non-destructive methods used in forensic fibres examinations (transmitted light microscopy, fluorescence microscopy, UV–Vis microspectrophotometry and Raman spectroscopy) has shown that efficiency in fibres differentiation is similar for all methods. TLC coupled with VSC was even found to be more effective in differentiation of red cotton fibres. The chemometric analysis was helpful to discriminate dyed cotton fibres, characterized by very similar colour.
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•Dyes extraction by enzymatic digestion effective for market red cotton fibres.•A separation procedure of the extracted dyes by TLC was elaborated.•Effective results interpretation with the use of the light of different lengths.•Efficiency of fibres differentiation by TLC higher than routine methods.•Chemometric analysis help to discriminate cotton fibres of similar red colour.
•Several design options for automotive acoustic components are compared using a LCA.•Options discussed include either non-renewable materials or recycled natural fibres.•The analysis confirms the ...environmental advantages of the natural fibres in these applications.•The environmental behaviour of recycled natural fibres is highlighted, thanks to the “50/50” allocation split.•The importance of using similar environmental assessment in multi-objective ecodesign process is underlined.
This paper summarizes the results and the lessons learnt from an LCA case study comparing acoustic automotive components. Three alternative acoustic components produced by the Brazilian automotive sector are considered: dual-layer polyurethane (DL-PU) panel, recycled textile absorption-barrier-absorption (ABA-cotton) panel and recycled textile DL (DL-cotton) panel. DL-PU is a “status-quo” alternative, composed mainly of synthetic plastics and the two other alternatives are mainly made of recycled cotton fibres. Using the Life Cycle Assessment (LCA) method, the three following phases of the panels’ life cycle are examined: production, use and end-of-life. For the latter, two end-of-life scenarios are analysed: landfill and incineration with energy recovery. For the LCA model, some Life Cycle Inventory (LCI) datasets have been adapted from the data available in the EcoInvent database in order to adjust to the Brazilian context. LCA results show that, within the entire life cycle, the DL-cotton option, which combines two layers of recycled fibres of different densities, is overall the best alternative from an environmental perspective. This result is therefore independent from the end-of-life scenario. This is mainly due to the lower weight of this component, which is extremely important for the transportation aspects, but also due to its lower consumption of fossil resources, to the energy saving during its production and to the avoidance of textile disposal that would happen otherwise. The obtained results confirm the available literature dealing with the use of renewable fibres in industrial products. The particular behaviour of recycled fibres compared to virgin ones (in terms of shared contribution of agricultural production and of avoidance of landfilling) is highlighted in this paper, thanks to the application of the “50/50” allocation rule. LCA results are discussed in terms of their potential use in an R&D context. Further research needs are also derived from the case study, including the potential benefits of developing multi-objective optimization methods that include environmental impact to be used in the design of such a component.
Novel analytical techniques are successfully applied to quantify physical changes in cotton fibre during development. Display omitted
•Maturity ratio increases as the fibres develop.•Birefringence ...increases rapidly from 17dpa to 26dpa; levels off up to 60dpa.•Significant increase in degree of cellulose crystallinity from 17dpa to 26dpa.•HBI increased to 24dpa; decreased from 24 to 40dpa.•Significant changes in inter-molecular hydrogen bonds during development.
Cotton fibres develop over four stages: initiation, elongation, secondary-wall thickening, and maturation. They develop a significant crystalline structure during the secondary wall thickening stage of development. Cotton fibres were harvested from 17days to 60days after flowering (dpa). Transmission Electron Microscopy (TEM), Interferometry, Attenuated Total Reflectance Fourier–transform Infrared (ATR–FTIR) spectroscopy, immunofluorescence labelling, and fluorescence spectroscopy were used to characterise the cotton fibres in different stages. It was found that, secondary wall thickening and micronaire remain fairly constant from 17 to 24dpa, after that time significant change occurs until maturity. Maturity ratio increases as the fibres develop. Birefringence increases rapidly from 17dpa to 26dpa, then levels off up to 60dpa. It is evident by comparing the lateral order index (LOI) and results from the binding of a crystalline-cellulose binding probe (CBM3a) that there is a significant increase in the degree of cellulose crystallinity from 17dpa to 26dpa. Hydrogen Bond Intensity (HBI) increased to 24dpa and decreased from 24 to 40dpa indicating significant changes in inter-molecular hydrogen bonds. From 40 to 60dpa an increase of HBI was observed. It is concluded that during the maturation stage of cotton fibre development, water loss from lumen allows the cellulose chains to come closer together and to form intermolecular hydrogen-bonds. TEM, Interferometry, ATR–FTIR spectroscopy, and immunofluorescence labelling combined with fluorescence spectroscopy, were demonstrated to be useful techniques in quantifying physical changes in cotton fibres during development, offering advantages over traditional analytical techniques.
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