The potential role of natural textile fibres as environmental pollutants has been speculated upon by some environmental scientists, however, there is a general consensus that their biodegradability ...reduces their environmental threat. Whilst the risks that they pose remain poorly understood, their environmental prevalence has been noted in several recent microplastic pollution manuscripts. Here we highlight the extent to which natural textile fibres dominate fibre populations of upstream reaches of the River Trent, UK, as well as the atmospheric deposition within its catchment, over a twelve month microplastic sampling campaign. Across 223 samples, natural textile fibres represented 93.8% of the textile fibre population quantified. Moreover, though microplastic particles including synthetic fibres are known to be pervasive environmental pollutants, extruded textile fibres were absent from 82.8% of samples. Natural textile fibres were absent from just 9.7% of samples.
Display omitted
•Natural textile fibres dominate freshwater and atmospheric fibre populations.•Environmental concentrations of textile fibres vary greatly through time and space.•Upstream textile fibre concentrations can exceed that of the Marne River in Paris.•Atmospheric deposition is a potential source of textile fibres in remote locations.•Atmospheric deposition of textile fibres is not correlated to precipitation.
Display omitted
•A regenerated keratin membrane was designed to simulate the natural Murray network.•The keratin membrane has excellent directional water transmission ability against gravity.•The ...regenerated keratin membrane shows excellent water absorption and desorption properties.•Pure regenerated keratin membrane is applied to solar-assisted atmospheric water collection.
In addressing the challenge of water scarcity, solar-assisted atmospheric water harvesting (SAWH) has emerged as a promising strategy. Here, we have designed a hierarchical regenerated wool keratin membrane (LiCl@CNMC) that mimics the natural Murray network. Carbon nano tube, serving as solar absorbers, are uniformly deposited on the hierarchical keratin membrane. Hygroscopic salt LiCl is impregnated into the keratin membrane to achieve exceptional water uptake capacity. Under simulated sunlight exposure, the surface temperature can reach 83.5 °C. Furthermore, the LiCl@CNMC membrane exhibits outstanding water absorption (0.79–2.67 g g−1) and desorption performance at 30–80 % RH. The bionic water-collecting membrane can carry out 12 adsorption–desorption cycles every day under outdoor conditions, and yielding 11.92 g g−1 day−1 of clean water. The design of regenerated keratin membrane not only provides a direct way for the regeneration and utilization of keratin materials, but also provides valuable guidance and inspiration for the preparation and application of natural polymers found.
The increasing demand for cellulosic fibres is continuously driven by the growing earth population and requirements of the textile industry. The annual cotton production of ca. 25 million tons is no ...longer enough to meet the market demands. This market gap of cellulosic fibres is progressively filled by regenerated cellulosic fibres derived from the dissolving pulp. The conventional industrial process of viscose production is far from being environmentally friendly due to the use of hazardous reagents. Alternatively, new trends in the production of regenerated fibres are related to the direct dissolution of cellulose in appropriate environmentally sound recyclable solvents, allowing high quality rayon fibres. This article reviews the sources of dissolving pulps used for the production of viscose and its quality parameters related to the performance of viscose production. The prospective cellulose regeneration processes, both commercialized and under development, are reviewed regarding current and future developments in the area.
Display omitted
•Specific properties of dissolving pulps to produce rayon fibres are summarized.•Drawbacks of the conventional viscose process are highlighted.•Commercialized direct dissolution lyocell process has limitations.•Greener approaches include ionic liquids and deep eutectic solvents.•Chemical recycling of textile fibres is a challenging research topic.
Display omitted
•Fast fractionation of softwood to yield textile fiber and biofuel.•Hydrocarbon yields beyond the theoretical maximum from beta-ether cleavage.•Hydrotreatment of lignin using refinery ...parameters enabled by dissolution in furfural.•Comparative life cycle assessment show superior environmental performance to cotton.
To achieve a viable forest-based biorefinery, both the carbohydrate and lignin parts of the raw material should be valorized. While lignin-first approaches have successfully been applied to hardwoods, where up to 50% of the lignin –close to the ‘theoretical maximum yield’– has been transformed to valuable monophenols; limited studies have targeted softwoods. Softwood lignin comprises lower amount of beta-ether bonds and this results in lower theoretical and observed yields of monophenols in reductive catalytic fractionation (RCF): below 5 wt% yield of initial biomass has been reported. In this study, we use beetle infected spruce, a softwood, as raw material. A fast fractionation was developed to give a pulp and a lignin fraction in the absence of transition metal catalysts. The carbohydrate matrix was valorized to dissolving grade pulp in 37 wt% from biomass (86% yield), and successfully spun to Lyocell fibers. The lignin fraction was dissolved in furfural –operating as green ‘solubility-enhancing-agent’– to blend lignin in inert carrier liquids to promote controlled hydrotreatment to yield biofuels in 10 wt% (60% carbon yield) from initial biomass. Life cycle assessment (LCA) of the value-chain showed improved sustainability in several footprint categories compared to cotton production. Thus, upgrading of a considered forestry waste to high value textile fibers and biofuels has been achieved: in case of lignin beyond the ‘theoretical maximum yield’. This is an important step to mitigate a future growing demand of textiles without negatively affecting irrigation or land use.
Textile fibre is very common in daily life, and its classification and identification play an important role in textile recycling, archaeology, public security, and other industries. However, ...traditional identification methods are time-consuming, laborious, and often destructive to the samples. In order to quickly, accurately, and nondestructively classify and recognize textile fibres, this study established a textile fibre classification and recognition method based on hyperspectral imaging (HSI) and a one-dimensional convolutional neural network (1D-CNN) model. Hyperspectral images of 25 kinds of commercial textile fibres were collected and denoised by pixel fusion. Four traditional machine learning classification models, k-nearest neighbors (KNN), support vector machine (SVM), random forest (RF), and partial least squares-discriminant analysis (PLS-DA), were used to identify the data. The results show that RF has the highest classification accuracy, reaching 91.4%. Then a back propagation neural network (BPNN) model and a one-dimensional convolutional neural network (1D-CNN) model were constructed and compared with the traditional machine learning methods. The results show that the 1D-CNN models have 97.9% and 98.6% accuracy on the training and test sets, respectively. The precision (Pr), sensitivity (Se), specificity (Sp), and F1 score (F1 score) of the models reached 98.7%, 98.6%, 99.9%, and 98.6%, respectively, which were significantly better than the four traditional machine learning models. It seems that 1D-CNN combined with the HSI technique may be a potential method in the detection and classification of textile fibres.
Display omitted
•·Hyperspectral technique was proposed to classify and identify textile fibers.•·The spectra were preprocessed by pixel fusion method.•·One-dimensional convolutional neural network model was built to classify hyperspectral data.•·Based on hyperspectral data, the traditional machine learning method and neural network method are compared.
Atmospheric microplastics have been widely reported in studies around the world. Microfibres are often the dominant morphology found by researchers, although synthetic (i.e., plastic) microfibres are ...typically just a fraction of the total number of microfibres, with other, non-synthetic, cellulosic microfibres frequently being reported. This study set out to review existing literature to determine the relative proportion of cellulosic and synthetic atmospheric anthropogenic (man-made) microfibres, discuss trends in the microfibre abundances, and outline proposed best-practices for future studies. We conducted a systematic review of the existing literature and identified 33 peer-reviewed articles from Scopus and Google Scholar searches that examined cellulosic microfibres and synthetic microfibres in the atmosphere. Multiple analyses indicate that cellulosic microfibres are considerably more common than synthetic microfibres. FT-IR and Raman spectroscopy data obtained from 24 studies, showed that 57% of microfibres were cellulosic and 23% were synthetic. The remaining were either inorganic, or not determined. In total, 20 studies identified more cellulosic microfibres, compared to 11 studies which identified more synthetic microfibres. The data show that cellulosic microfibres are 2.5 times more abundant between 2016 and 2022, however, the proportion of cellulosic microfibres appear to be decreasing, while synthetic microfibres are increasing. We expect a crossover to happen by 2030, where synthetic microfibres will be dominant in the atmosphere. We propose that future studies on atmospheric anthropogenic microfibres should include information on natural and regenerated cellulosic microfibres, and design studies which are inclusive of cellulosic microfibres during analysis and reporting. This will allow researchers to monitor trends in the composition of atmospheric microfibers and will help address the frequent underestimation of cellulosic microfibre abundance in the atmosphere.
•Review of 33 studies which examined atmospheric anthropogenic microfibres. .•61% of studies identified more cellulosic microfibres in the atmosphere.•From 14,200 particles and microfibres, 57% were cellulosic and 23% were synthetic.•Synthetic fibres are increasing their relative abundance in the atmosphere.•Synthetic fibres may exceed cellulosic fibres in the atmosphere between 2025 and 2030.
Display omitted
•Sustainable biocomposites were developed from agricultural by-products.•Rice husk biocomposites had the least thermal conductivity (0.08 W/m.K).•Biocomposites showed semi-rigid ...mechanical properties with good thermal stability.•Focused biocomposites can be considered as potential alternative for conventional building insulation.
Building materials derived from agricultural and industrial waste are becoming more attractive in the civil engineering and architectural applications because of their sustainability and lower environmental impact. In addition, substantial value can be added to the wastes by producing value added products from them. Therefore, four different types of locally available by-products (rice husk, wheat husk, wood fibers and textile waste fibers) were used to produce composites with a biodegradable poly(butylene adipate-co-terephthalate)/poly(lactic acid) (PBAT/PLA) blend binder by hot pressing. The morphological analysis of the composites revealed that the PBAT/PLA binder had more affinity with wood and textile fibers than with wheat and rice husks. The prepared composites showed thermal stability until 250 °C. All the prepared biodegradable composites exhibited good compressive strength (11–40 MPa) and flexural strength (0.80–2.25 MPa). The observed mechanical properties allow easy handling without risk of breaking them when positioned in the buildings. The biodegradable composites were characterized for their thermal conductivity, diffusivity, effusivity and heat capacity. The density and thermal conductivity of the produced composite was in the range of 378–488 kg/m3 and 0.08-0.14 W/m.K, respectively. The least thermal conductivity i.e. 0.08 W/m.K was observed for the rice husk composite with a density of 378 kg/m3. A minimum water absorption (42%) was found in the rice husk composites after 24 h immersion in water. The composite samples were still cohesive after 24 h immersion in the water because of the water resistance nature of the binder. The prepared biodegradable composites meet most of the required properties for the indoor building insulation applications and show great potential to replace the conventional building material in current use.
Dynamic Behavior of Twisted UHMWPE Yarns Wang, Haoxiang; Shen, Yue; Wei, Jian ...
Composites. Part A, Applied science and manufacturing,
September 2024, 2024-09-00, Letnik:
184
Journal Article
Recenzirano
•Five types of ultra-high molecular weight polyethylene yarns with different twisting degrees were manufactured, namely 0, 250, 500, 750, and 1000 t/m.•Dynamic tensile experiments were designed, and ...the failure processes of yarns were visualized.•The twist effect, strain rate effect, and length effect of twisted yarn were analyzed.
Twisting is an effective method to reduce defects during fabric weaving and improve the impact resistance of the armor material. This study examined the dynamic behavior of twisted ultra-high molecular weight polyethylene (UHMWPE) yarns. Material characterization was conducted using three-dimensional X-ray tomography and scanning electron microscopy (SEM). Dynamic mechanical experiments were carried out on the twisted yarns using a Kolsky bar, with the yarn's failure process captured in real time through high-speed imaging. Additionally, the digital imaging correlation (DIC) technique was used to calibrate the strain measured by the Kolsky bar. Post-fracture analysis was performed using SEM. The effects of twisting extent, strain rate, and gauge length on the dynamic behavior of twisted yarns were studied. It was observed that all twisted yarns underwent elongation, shrinkage, fiber breakage, untwisting, and yarn rupture. Furthermore, as the twisting degree and strain rate increased, and the gauge length decreased, the fracture area became more concentrated. The tensile strength peaked at a twisting degree of 250 t/m and decreased thereafter. Moreover, twisting was found to alter the sensitivity of the yarns' stress–strain curves and tensile properties to the strain rate and gauge length.
In this study, a triple-layered coaxial fibre structure was fabricated for strain sensor applications. The core consisted of melt-spun poly (ethylene terephthalate) (PET) where in a subsequent step ...carbon black (CB) particles were coated onto the surface of the PET fibre to build the conductive pathways by a dissolving-coating method. For the outer protective sheath, a thermoplastic polyurethane (TPU) with a thickness of about 7 μm was generated using a layer-by-layer assembly technique. Compared with other investigated CB-coated fibres, the novel triple hierarchic PET/CB/TPU composite fibres exhibit a high Young’s modulus and tensile strength, as well as a doubled sensing range. The fabrication process can be directly used in the textile industry for the production of wearable and flexible sensors due to its efficacy and low cost. Moreover, a model based on tunnelling theory utilizing only two adjustable parameters was modified based on the actual experimental data, which could precisely describe the relative change of resistance upon the applied strain. Meanwhile, an empirical equation was first proposed and this model offers an effective but simple approach towards quantitative analysis of strain sensors.
In this work, we demonstrate multifunctional and flexible polymeric wearable heaters with highly-efficient electro-/photothermal performance by constructing 3D AgNW@MXene conductive network on the ...fiber surface, which is realized by a simple alternating solution dip coating technique. The temperature of AgNW@MXene decorated polymeric textile (AM-textile) heater can reach to a high value of 215 ℃ at comparable low voltage (3.5 V), and to 224 °C rapidly within 10 s under a near infrared laser light (100 mW). In addition, a triboelectric nanogenerator using the AM-textile as electrode can transform electrical signal with an open circuit voltage of 62 V through collecting energy from small human movement. Meanwhile, the AM-textile not only maintains the breathability and flexibility of the pristine polymeric textile, but also exhibits excellent antibacterial, flame retardant, and electromagnetic interference shielding ability at the same time, showing great potential for applications in multifunctional wearable heater and self-powered electronic device.
PDF
