Summary
Cellulose is one of the most abundant organic polymers in nature. It contains multiple β‐1,4‐glucan chains synthesized by cellulose synthases (CesAs) on the plasma membrane of higher plants. ...CesA subunits assemble into a pseudo‐sixfold symmetric cellulose synthase complex (CSC), known as a ‘rosette complex’. The structure of CesA remains enigmatic. Here, we report the cryo‐EM structure of the homotrimeric CesA7 from Gossypium hirsutum at 3.5‐angstrom resolution. The GhCesA7 homotrimer shows a C3 symmetrical assembly. Each protomer contains seven transmembrane helices (TMs) which form a channel potentially facilitating the release of newly synthesized glucans. The cytoplasmic glycosyltransferase domain (GT domain) of GhCesA7 protrudes from the membrane, and its catalytic pocket is directed towards the TM pore. The homotrimer GhCesA7 is stabilized by the transmembrane helix 7 (TM7) and the plant‐conserved region (PCR) domains. It represents the building block of CSCs and facilitates microfibril formation. This structure provides insight into how eukaryotic cellulose synthase assembles and provides a mechanistic basis for the improvement of cotton fibre quality in the future.
The speed with which fashion trends change encourages excessive consumption and inadequate management of textile waste. Therefore, the use of recycled cotton fibres (RCF), as a sustainable ...alternative, by textile industries has taken on greater relevance; however, there are uncertainties about its implementation and appropriate method. Therefore, this review aims to identify the method of blending recycled cotton fibres to produce new yarns. For this, the PICO method was used to define the research questions and keywords; Then, it was complemented with the PRISMA methodology to search for information in the Scopus and ProQuest databases. The information found was analyzed in an Ishikawa diagram and later in a Pareto diagram. Finally, it was concluded that the most suitable RCF blending method is 50% VCF with 50% RCF. If more RCFs were added, the products would not meet the optimal quality measures for their production and marketing. Likewise, the main limitations to implementing the method are the adequate selection of the type of recycling, a high financial outlay for the classification of fibres legal loopholes such as the lack of supervision by the government, and inadequate implementation of the extended responsibility policy (EPR). Furthermore, the lack of specific regulations on textile recycling and the absence of certifications for companies that adopt sustainable practices represent additional obstacles.
The proportion of woven fabrics in the broad field of protective textiles is extremely high. By various procedures (surface treatments, fabric lamination, composite production), fabric properties ...that meet the requirements defined by standards are achieved. However, simultaneously, these procedures cause negative effects in the form of fabric thickness, stiffness, impermeability, non-breathability, and thus, discomfort. Therefore, there are valid and justified reasons to approach the design process of making such woven fabrics using more complex construction solutions—layer interchanging double cloth. In addition, by applying fibres with integrated desired properties and other structural fabric parameters, it is possible to influence the achievement of the properties of multi-purpose multilayer fabrics for protection, which is the aim of this research. The application and combination of aramid and modacrylic/cotton fibres and use of different yarn fineness resulted in different intensities of protection. The correlative values of mentioned parameters and thermal and thermo-physiological properties indicate their strong connection, and thus the effectiveness of the developed woven fabric samples.
•Protective layers for con concrete element.•Impact behavior of Concrete element covered with Cotton-FRP, Cotton-FRCM and polyurea.•Tensile Characterization of Cotton-FRP, Cotton-FRCM and Polyurea.
...During their lifetimes, concrete structures can be subjected to impact actions that can cause considerable damage or collapse. This paper proposes the use of protective layers and/or deformable coating materials to prevent significant damage to concrete elements. The selected systems included a cotton-fabric-reinforced cementitious matrix (Cotton-FRCM), fibre-reinforced polymers (cotton-FRP), and two types of polyurea. The materials were subjected to tensile tests to analyse their mechanical properties. To assess the effectiveness of the protective layers, concrete specimens were externally reinforced to perform ultrasound and impact tests. The results demonstrated that a polyurea coating formed the most effective protective layer for avoiding immediate damage to the concrete specimen because of its deformation capacity. However, the stiffness behaviour, deflection energy, and composite action presented by the specimen strengthened by cotton-FRCMs on both faces suggest that this system can be more effective for higher impact energies.
Fragments of single textile fibres are one of the most commonly found microtraces at crime scenes. Among them, the widespread blue and black/grey cotton fibres should be recognized. The analytical ...methods routinely used in fibre examination mainly focus on color assessment and determination of the fibres’ morphological features as well as chemical composition. This publication presents the physicochemical characteristics of blue and black/grey denim fabrics and fibres as well as an overview of the non-destructive and destructive methods used in the discrimination of these fibres. Usually, such fibre microtraces are very difficult to distinguish in forensic examinations due to their widespread abundance, and, thus, their evidential value is not significant. As previous research shows, most denim material samples were colored with indigo dye. However, due to the changing trends in denim production and the fashion market, indigo derivatives may play a more critical role. The literature review shows significant shortcomings in the development of techniques focusing on the analysis of the dyes contained in denim fibres, and this is a research direction worth pursuing.
Carbon xerogels have generally low textural properties compared with carbon aerogels and carbon cryogels since the gas-liquid interface produces a capillary force in small pores. In this work, the ...templated carbon xerogels (TCXs), using resorcinol-formaldehyde (RF) and cotton fibres (CFs) as a hard template, were synthesized by CF removal from CF/RF composite hydrogels by sulphuric acid treatment. The TCX precursors were exchanged by t-butanol, dried by evaporation drying, and carbonized at high temperature. Scanning electron microscope images and Hg intrusion data confirm that TCXs possess macropores whose walls are the carbon xerogel scaffold. Their nitrogen adsorption and desorption isotherms also support that TCXs have micropores and mesopores. The quantities of micropores, mesopores and macropores are improved with the increase of CF utilization. X-ray diffraction allows us to know that TCXs have a graphitic structure. The intensity of D to G from the Raman spectra is also investigated.
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•TCXs prepared by using H2SO4 treatment have micropores, mesopores, and macropores.•The carbon xerogel scaffold acts as the macropore wall.•The greater the CF utilization, the greater the textural properties of TCXs.•The macropores are created by CF removal from the CF/RF composite hydrogels.•The low R/W ratio, 0.25 g/cm3, enhances the increase of micropores and mesopores.
•Development of NiO-SnO2/CMC coated cotton fibres.•Efficient catalyst for the reduction of organic/inorganic pollutants.•Reusability of designed catalyst for three cycles.
A nanocomposite of nickel ...oxide and tin oxide (NiO-SnO2) was prepared by mixing with carboxymethylcellulose (CMC) and coated on natural cotton fibers (CF). NiO-SnO2 coated CF (NiO-SnO2/CF) was examined as catalyst for decolorization and reduction of different water contaminants. NiO-SnO2/CF showed the highest rate constant (1.1087 min−1) for methylene blue (MB) reduction. Thus, comparative reduction study showed that NiO-SnO2/CF is a stable and best catalyst for MB reduction. With the increase of the amount of catalyst from 10 to 15 mg, the 98% reduction of MB was achieved in 4.0 and 3.0 min, respectively, Moreover, MB concentration, amount of reducing agent, stability and recyclability were investigated and optimized. NiO-SnO2/CF appeared to be a best catalyst for efficient removal of MB because it retained superior catalytic activity, stability and recyclability in the reduction reaction of MB. The advantage of the developed NiO-SnO2/CF catalyst is that it can be simply retrieve by easy towing out from reaction media which is the main advantage of using the CF support. The developed nanocatalyst gives a new cost and time effective material and route for efficient reduction of MB for environmental safety.
The development of eco- friendly environmental and sustainable building materials having low thermal conductivity and optimal physic-chemical abilities ensuring passive thermal comfort is imperative ...in the global quest for the minimization of greenhouse-gases (GHG) emission and energy needs in homes. To attend this objective, the present work underlines the feasibility of using waste cotton fibres for the design of the lightweight laterite-cement composites with low thermal conductivity for structural applications. The final products were obtained by replacing laterite cement composite with cotton wastes fibres (0.3-0.6 wt%) and then uniaxial pressing around 14 MPa. The thermo-engineering and structural properties were performed using several techniques: X-Ray Diffraction (XRD), Environmental Scanning Electron Microscope (ESEM), Fourier Transform Infrared Spectroscopy (FTIR), mechanical properties as well as thermal conductivity. This process accounts for the optimum (0.78 W.m
−1
. K
−1
) structural material made with 6 wt% cement, 0.6 wt% cotton fibres and better packing density of laterites particles (50/50). Regardless of the particle size distribution of aggregates (laterite), the increase of cotton fibres content resulted in lowering mechanical performances. This is due to the creation of pores and the weakness adhesion between the cellulosic fibres and laterites particles within the matrix. In addition, the presence of cellulose within a matrix enhanced the crystallinity of cementitious phases (CASFH and CASH) of the end-products. The formulated samples with the reduction around 29% of embodied energy compared to the conventional materials, appears as a promising eco-friendly composite with good thermal comfort, small-embodied energy and low environmental impact through sustainable process.
Performance of fabrics produced from torque-free ring spun yarns and conventional ring spun yarns with the use of three different varieties of cotton fibre (pima cotton, upland cotton and organic ...cotton) in terms of handle and the pilling resistance was compared. results show that fabrics produced from torque-free ring spun yarns exhibit better surface appearance, better softness and smoothness as compared to conventional ring spun yarns, irrespective of which of the three varieties of cotton was used. The greatest improvement of fabric hand was obtained by using torque-free ring spun yarns with Upland Cotton. The soft twist of the torque-free ring spun yarn did not intensify the pilling propensity but improved the pilling resistance instead.
The circular economy is emerging as green technology solution for polymer and composite industries. However, the use of circular economy as an industrial practice is still a global challenge. In this ...article, polypropylene-cotton hybrid composite was developed using different amounts of cotton fibre waste (0, 10, 30, 40 wt%). Scanning electron microscope (SEM), tribometer, Rockwell hardness tester and binocular microscope were used for investigations of composite surface, hardness and coefficient of friction (COF). The mean coefficient of friction values was 0.64, 0.75, 0.88 and 0.94 for pure propylene, 10, 30 and 40% of cotton reinforced composites, respectively. The scanning electron microscopy characterization of hybrid composite revealed the voids, porosity and asperities due to random fibres orientation. The Rockwell hardness value of composites was increased due to rise of fibre fraction. Based on the COF values, hardness and surface characterization, polypropylene-cotton reinforced hybrid composite could be used functionally for thermal and sound applications.
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