Structure of cellulose microfibrils in mature cotton fibres

Chemical mapping of xyloglucan distribution and cellulose crystallinity in cotton textiles reveals novel enzymatic targets to improve clothing longevity

Pilling is a form of textile mechanical damage, forming fibrous bobbles on the surface of garments, resulting in premature disposal of clothing by consumers. However, our understanding on how the structural properties of the cellulosic matrix compliment the three-dimensional shape of cotton pills remains limited. This knowledge gap has hindered the development of effective 'pillase' technologies over the past 20 years due to challenges in balancing depilling efficacy with fabric integrity preservation. Therefore, the main focus here was characterising the role of cellulose and the hemicellulose components in cotton textiles to elucidate subtle differences between the chemistry of pills and fibre regions involved in structural integrity. State-of-the-art bioimaging using carbohydrate binding modules, monoclonal antibodies, and Leica SP8 and a Nikon A1R confocal microscopes, revealed the biophysical structure of cotton pills for the first time. Identifying regions of increased crystalline cellulose in the base of anchor fibres and weaker amorphous cellulose at dislocations in their centres, enhancing our understanding of current enzyme specificity. Surprisingly, pills contained a 7-fold increase in the concentration of xyloglucan compared to the main textile. Therefore, xyloglucan offers a previously undescribed target for overcoming this benefit-to-risk paradigm, suggesting a role for xyloglucanase enzymes in future pillase systems.

Silver oxide doped iron oxide/alginate nanocomposite coated cotton cloth for selective catalytic reduction of potassium ferricyanide

Silver oxide doped iron oxide (Ag2O-Fe2O3) nanocatalyst was prepared and coated on cotton cloth (CC) as well as wrapped in sodium alginate (Alg) hydrogel. Ag2O-Fe2O3 coated CC (Ag2O-Fe2O3/CC) and Ag2O-Fe2O3 wrapped Alg (Ag2O-Fe2O3/Alg) were utilized as catalysts in reduction reaction of 4-nitrophenol (4-NP), congo red (CR), methylene blue (MB) and potassium ferricyanide (K3[Fe(CN)6]). Ag2O-Fe2O3/CC and Ag2O-Fe2O3/Alg were found to be effective and selective catalyst for the reaction of K3[Fe(CN)6]. Further amount of catalyst, K3[Fe(CN)6] quantity, amount of NaBH4, stability of catalyst and recyclability were optimized for the reaction of K3[Fe(CN)6] reduction. Ag2O-Fe2O3/Alg and Ag2O-Fe2O3/CC were appeared to be the stable catalysts by maintaining high activity during recyclability tests showing highest reaction rate constants (kapp) of 0.3472 and 0.5629 min-1, correspondingly. However, Ag2O-Fe2O3/CC can be easily recovered as compared to Ag2O-Fe2O3/Alg by simply removing from the reaction which is the main advantage of Ag2O-Fe2O3/CC. Moreover, Ag2O-Fe2O3/Alg and Ag2O-Fe2O3/CC were also examined in real samples and found useful for K3[Fe(CN)6] reduction involving real samples. The Ag2O-Fe2O3/CC nanocatalyst is a cost and time saving material for economical reduction of K3[Fe(CN)6] and environmental safety.

Characteristics of Dialdehyde Cellulose Nanofibrils Derived from Cotton Linter Fibers and Wood Fibers

Two types of cellulose nanofibrils (CNFs) were isolated from cotton linter fibers and hardwood fibers through mechanical fibrillation methods. The dialdehyde cellulose nanofibrils (DACNFs) were prepared through the periodate oxidation method, and their morphological and structural properties were investigated. The characteristics of the DACNFs during the concentration process were also explored. The AFM analysis results showed that the mean diameters of wood fiber-based CNFs and cotton fiber-based CNFs were about 52.03 nm and 69.51 nm, respectively. However, the periodate oxidation treatment process obviously reduced the nanofibril size and destroyed the crystalline region of the nanofibrils. Due to the high crystallinity of cotton fibers, the cotton fiber-based DACNFs exhibited a lower aldehyde content and suspension stability compared to the wood fiber-based DACNFs. For the concentration process of the DACNF suspension, the bound water content of the concentrated cotton fiber-based DACNFs was lowered to 0.41 g/g, which indicated that the cotton fiber-based DACNFs could have good redispersibility. Both the wood fiber-based and cotton fiber-based DACNF films showed relatively good transmittance and mechanical strength. In addition, to the cotton fiber-based DACNF films had a very low swelling ratio, and the barrier water vapor and oxygen properties of the redispersed cotton fiber-based DACNF films decreased by very little. In sum, this study has demonstrated that cotton fibers could serve as an effective alternative to wood fibers for preparing CNFs, and that cotton fiber-based DACNFs have huge application prospects in the field of packaging film materials due to their stable properties during the concentration process.

Poly(Allylamine Hydrochloride) and ZnO Nanohybrid Coating for the Development of Hydrophobic, Antibacterial, and Biocompatible Textiles

In healthcare facilities, infections caused by Staphylococcus aureus (S. aureus) from textile materials are a cause for concern, and nanomaterials are one of the solutions; however, their impact on safety and biocompatibility with the human body must not be neglected. This study aimed to develop a novel multilayer coating with poly(allylamine hydrochloride) (PAH) and immobilized ZnO nanoparticles (ZnO NPs) to make efficient antibacterial and biocompatible cotton, polyester, and nylon textiles. For this purpose, the coated textiles were characterized with profilometry, contact angles, and electrokinetic analyzer measurements. The ZnO NPs on the textiles were analyzed by scanning electron microscopy and inductively coupled plasma mass spectrometry. The antibacterial tests were conducted with S. aureus and biocompatibility with immortalized human keratinocyte cells. The results demonstrated successful PAH/ZnO coating formation on the textiles, demonstrating weak hydrophobic properties. Furthermore, PAH multilayers caused complete ZnO NP immobilization on the coated textiles. All coated textiles showed strong growth inhibition (2-3-log reduction) in planktonic and adhered S. aureus cells. The bacterial viability was reduced by more than 99%. Cotton, due to its better ZnO NP adherence, demonstrated a slightly higher antibacterial performance than polyester and nylon. The coating procedure enables the binding of ZnO NPs in an amount (<30 µg cm-2) that, after complete dissolution, is significantly below the concentration causing cytotoxicity (10 µg mL-1).

Acetylation of Nanocellulose: Miscibility and Reinforcement Mechanisms in Polymer Nanocomposites

The improvement of properties in nanocomposites obtained by topochemical surface modification, e.g., acetylation, of the nanoparticles is often ascribed to improved compatibility between the nanoparticle and the matrix. It is not always clear however what is intended: specific interactions at the interface leading to increased adhesion or the miscibility between the nanoparticle and the polymer. In this work, it is demonstrated that acetylation of cellulose nanocrystals greatly improves mechanical properties of their nanocomposites with polycaprolactone. In addition, molecular dynamics simulations with a combination of potential of mean force calculations and computational alchemy are employed to analyze the surface energies between the two components. The work of adhesion between the two phases decreases with acetylation. It is discussed how acetylation can still contribute to the miscibility, which leads to a stricter use of the concept of compatibility. The integrated experimental-modeling toolbox used has wide applicability for assessing changes in the miscibility of polymer nanocomposites.

Structural Color from Cellulose Nanocrystals or Chitin Nanocrystals: Self-Assembly, Optics, and Applications

Widespread concerns over the impact of human activity on the environment have resulted in a desire to replace artificial functional materials with naturally derived alternatives. As such, polysaccharides are drawing increasing attention due to offering a renewable, biodegradable, and biocompatible feedstock for functional nanomaterials. In particular, nanocrystals of cellulose and chitin have emerged as versatile and sustainable building blocks for diverse applications, ranging from mechanical reinforcement to structural coloration. Much of this interest arises from the tendency of these colloidally stable nanoparticles to self-organize in water into a lyotropic cholesteric liquid crystal, which can be readily manipulated in terms of its periodicity, structure, and geometry. Importantly, this helicoidal ordering can be retained into the solid-state, offering an accessible route to complex nanostructured films, coatings, and particles. In this review, the process of forming iridescent, structurally colored films from suspensions of cellulose nanocrystals (CNCs) is summarized and the mechanisms underlying the chemical and physical phenomena at each stage in the process explored. Analogy is then drawn with chitin nanocrystals (ChNCs), allowing for key differences to be critically assessed and strategies toward structural coloration to be presented. Importantly, the progress toward translating this technology from academia to industry is summarized, with unresolved scientific and technical questions put forward as challenges to the community.

Eco-Friendly Cellulose-Based Nonionic Antimicrobial Polymers with Excellent Biocompatibility, Nonleachability, and Polymer Miscibility

This study aims to prepare natural biomass-based nonionic antimicrobial polymers with excellent biocompatibility, nonleachability, antimicrobial activity, and polymer miscibility. Two new cellulose-based nonionic antimicrobial polymers (MIPA and MICA) containing many terminal indole groups were synthesized using a sustainable one-pot method. The structures and properties of the nonionic antimicrobial polymers were characterized using nuclear magnetic resonance hydrogen spectroscopy (1H NMR), infrared spectroscopy (FTIR), wide-angle X-ray diffractometry (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), gel chromatography (GPC), and other analytical techniques. The results showed that microcrystalline cellulose (MCC) molecules combined with indole derivatives through an esterification reaction to produce MICA and MIPA. The crystallinity of the prepared MICA and MIPA molecules decreased after MCC modification; their morphological structure changed from short fibrous to granular and showed better thermal stability and solubility. The paper diffusion method showed that both nonionic polymers had good bactericidal effects against the two common pathogenic bacteria Escherichia coli (E. coli, inhibition zone diameters >22 mm) and Staphylococcus aureus (S. aureus, inhibition zone diameters >38 mm). Moreover, MICA and MIPA showed good miscibility with biodegradable poly(vinyl alcohol) (PVA), and the miscible cellulose-based composite films (PVA-MICA and PVA-MIPA) showed good phase compatibility, light transmission, thermal stability (maximum thermal decomposition temperature >300 °C), biocompatibility, biological cell activity (no cytotoxicity), nonleachability, antimicrobial activity, and mechanical properties (maximum fracture elongation at >390%).

Wood cellulose microfibrils have a 24-chain core-shell nanostructure in seed plants

Wood cellulose microfibril (CMF) is the most abundant organic substance on Earth but its nanostructure remains poorly understood. There are controversies regarding the glucan chain number (N) of CMFs during initial synthesis and whether they become fused afterward. Here, we combined small-angle X-ray scattering, solid-state nuclear magnetic resonance and X-ray diffraction analyses to resolve CMF nanostructures in native wood. We developed small-angle X-ray scattering measurement methods for the cross-section aspect ratio and area of the crystalline-ordered CMF core, which has a higher scattering length density than the semidisordered shell zone. The 1:1 aspect ratio suggested that CMFs remain mostly segregated, not fused. The area measurement reflected the chain number in the core zone (Ncore). To measure the ratio of ordered cellulose over total cellulose (Roc) by solid-state nuclear magnetic resonance, we developed a method termed global iterative fitting of T1ρ-edited decay (GIFTED), in addition to the conventional proton spin relaxation editing method. Using the formula N = Ncore/Roc, most wood CMFs were found to contain 24 glucan chains, conserved between gymnosperm and angiosperm trees. The average CMF has a crystalline-ordered core of ~2.2 nm diameter and a semidisordered shell of ~0.5 nm thickness. In naturally and artificially aged wood, we observed only CMF aggregation (contact without crystalline continuity) but not fusion (forming a conjoined crystalline unit). This further argued against the existence of partially fused CMFs in new wood, overturning the recently proposed 18-chain fusion hypothesis. Our findings are important for advancing wood structural knowledge and more efficient use of wood resources in sustainable bio-economies.

Using deep eutectic solvent dissolved low-value cotton linter based efficient magnetic adsorbents for heavy metal removal

In this study, a novel magnetic bio-adsorbent was synthesized by modifying cotton linter (CL) cellulose with deep eutectic solvents (DESs) and Fe₃O₄ magnetic nanoparticles. The adsorption capacity of CL, Fe₃O₄/CL, Fe₃O₄/CL-oxidation, and Fe₃O₄/CL-DES for Cu²⁺ was 11.0, 66.1, 85.7, and 93.1 mg g^-1, respectively, under the optimal adsorption conditions of an initial pH value of 6.0, stirring rate of 300 rpm, and a temperature of 30 °C. The presence of Fe₃O₄ nanoparticles increased the proportion of hydroxyl groups and thus improved the ion-exchange ability of Cu²⁺. The dissolution of DES significantly decreased fiber crystallinity and increased the number of hydroxyl group (amorphous regions increased), thus improving the chelation reaction of Cu²⁺, which was favorable for surface adsorption. In addition, we used the Langmuir and Freundlich isothermal models to simulate the adsorption behavior of Fe₃O₄/CL-DES, and the results indicated that Cu²⁺ follows a Freundlich isotherm model of multilayer adsorption. The fitting of the adsorption kinetics model indicated that the adsorption process involves multiple adsorption mechanisms and can be described by a quasi-second-order model. These results provide a potential method for the preparation of high-efficiency adsorbents from low-value cotton linter, which has broad application prospects in wastewater treatment.

In silico studies of plant primary cell walls - structure and mechanics

Primary plant cell wall (PCW) is a highly organized network, its performance is dependent on cellulose, hemicellulose and pectic polysaccharides, their properties, interactions and assemblies. Their mutual relationships and functions in the cell wall can be better understood by means of conceptual models of their higher-order structures. Knowledge unified in the form of a conceptual model allows predictions to be made about the properties and behaviour of the system under study. Ongoing research in this field has resulted in a number of conceptual models of the cell wall. However, due to the currently limited research methods, the community of cell wall researchers have not reached a consensus favouring one model over another. Herein we present yet another research technique - numerical modelling - which is capable of resolving this issue. Even at the current stage of development of numerical techniques, due to their complexity, the in silico reconstruction of PCW remains a challenge for computational simulations. However, some difficulties have been overcome, thereby making it possible to produce advanced approximations of PCW structure and mechanics. This review summarizes the results concerning the simulation of polysaccharide interactions in PCW with regard to network fine structure, supramolecular properties and polysaccharide binding affinity. The in silico mechanical models presented herein incorporate certain physical and biomechanical aspects of cell wall architecture for the purposes of undertaking critical testing to bring about advances in our understanding of the mechanisms controlling cells and limiting cell wall expansion.

Cellulose-Chitosan Functional Biocomposites

Here, we present a detailed review of recent research and achievements in the field of combining two extremely important polysaccharides; namely, cellulose and chitosan. The most important properties of the two polysaccharides are outlined, giving rise to the interest in their combination. We present various structures and forms of composite materials that have been developed recently. Thus, aerogels, hydrogels, films, foams, membranes, fibres, and nanofibres are discussed, alongside the main techniques for their fabrication, such as coextrusion, co-casting, electrospinning, coating, and adsorption. It is shown that the combination of bacterial cellulose with chitosan has recently gained increasing attention. This is particularly attractive, because both are representative of a biopolymer that is biodegradable and friendly to humans and the environment. The rising standard of living and growing environmental awareness are the driving forces for the development of these materials. In this review, we have shown that the field of combining these two extraordinary polysaccharides is an inexhaustible source of ideas and opportunities for the development of advanced functional materials.

Spatioselective surface chemistry for the production of functional and chemically anisotropic nanocellulose colloids

Maximizing the benefits of nanomaterials from biomass requires unique considerations associated with their native chemical and physical structure. Both cellulose nanofibrils and nanocrystals are extracted from cellulose fibers via a top-down approach and have significantly advanced materials chemistry and set new benchmarks in the last decade. One major challenge has been to prepare defined and selectively modified nanocelluloses, which would, e.g., allow optimal particle interactions and thereby further improve the properties of processed materials. At the molecular and crystallite level, the surface of nanocelluloses offers an alternating chemical structure and functional groups of different reactivity, enabling straightforward avenues towards chemically anisotropic and molecularly patterned nanoparticles via spatioselective chemical modification. In this review, we will explain the influence and role of the multiscale hierarchy of cellulose fibers in chemical modifications, and critically discuss recent advances in selective surface chemistry of nanocelluloses. Finally, we will demonstrate the potential of those chemically anisotropic nanocelluloses in materials science and discuss challenges and opportunities in this field.

Prospecting cellulose fibre-reinforced composite membranes for sustainable remediation and mitigation of emerging contaminants

Many environmental pollutants caused by uncontrolled urbanization and rapid industrial growth have provoked serious concerns worldwide. These pollutants, including toxic metals, dyes, pharmaceuticals, pesticides, volatile organic compounds, and petroleum hydrocarbons, unenviably compromise the water quality and manifest a severe menace to aquatic entities and human beings. Therefore, it is of utmost importance to acquaint bio-nanocomposites with the capability to remove and decontaminate this extensive range of emerging pollutants. Recently, considerable emphasis has been devoted to developing low-cost novel materials obtained from natural resources accompanied by minimal toxicity to the environment. One such component is cellulose, naturally the most abundant organic polymer found in nature. Given bio-renewable sources, natural abundance, and impressive nanofibril arrangement, cellulose-reinforced composites are widely engineered and utilized for multiple applications, such as wastewater decontamination, energy storage devices, drug delivery systems, paper and pulp industries, construction industries, and adhesives, etc. Environmental remediation prospective is among the fascinating application of these cellulose-reinforced composites. This review discusses the structural attributes of cellulose, types of cellulose fibrils-based nano-biocomposites, preparatory techniques, and the potential of cellulose-based composites to remediate a diverse array of organic and inorganic pollutants in wastewater.

Enteromorpha cellulose micro-nanofibrils/poly(vinyl alcohol) based composite films with excellent hydrophilic, mechanical properties and improved thermal stability

This study presents the preparation of cellulose micro-nanofibrils (CMNFs) from Enteromorpha (EP) and the application in PVA/acetylated distarch phosphate (ADSP)/CMNFs composite films. The Micro-nano scale, hydrophilicity, and strong hydrogen bond characteristics of CMNFs prepared form EP by acid hydrolysis were confirmed through the granular statistics, XRD analysis and chemical structure analysis. With the addition of CMNFs, the ultimate tensile strength and elongation at break of composite films are increased by 42.4 % and 90.3 %. An original Weibull statistical analysis shows the impact of CMNFs' added amount on strength distribution and ultimate stress. SEM and polarizing microscope images show the CMNFs' dispersion state in that films is optimal, when their addition was to be 2 %-3 % of total dry weight of PVA/ADSP matrix， which is consistent with the results of Weibull modulus analysis. The main thermal weight-loss process of the composite film is divided into four stages, CMNFs can significantly increase the thermostability at 280 °C to 400 °C. The experiment of water contact angle and water vapor transmission rate of the composite films confirmed that CMNFs can improve films' hydrophilicity. This study provides basis for the preparation of hydrophilic CMNFs and mechanism of modification study PVA-based composites.

Cotton Breeding in Australia: Meeting the Challenges of the 21st Century

The Commonwealth Scientific and Industrial Research Organisation (CSIRO) cotton breeding program is the sole breeding effort for cotton in Australia, developing high performing cultivars for the local industry which is worth∼AU$3 billion per annum. The program is supported by Cotton Breeding Australia, a Joint Venture between CSIRO and the program's commercial partner, Cotton Seed Distributors Ltd. (CSD). While the Australian industry is the focus, CSIRO cultivars have global impact in North America, South America, and Europe. The program is unique compared with many other public and commercial breeding programs because it focuses on diverse and integrated research with commercial outcomes. It represents the full research pipeline, supporting extensive long-term fundamental molecular research; native and genetically modified (GM) trait development; germplasm enhancement focused on yield and fiber quality improvements; integration of third-party GM traits; all culminating in the release of new commercial cultivars. This review presents evidence of past breeding successes and outlines current breeding efforts, in the areas of yield and fiber quality improvement, as well as the development of germplasm that is resistant to pests, diseases and abiotic stressors. The success of the program is based on the development of superior germplasm largely through field phenotyping, together with strong commercial partnerships with CSD and Bayer CropScience. These relationships assist in having a shared focus and ensuring commercial impact is maintained, while also providing access to markets, traits, and technology. The historical successes, current foci and future requirements of the CSIRO cotton breeding program have been used to develop a framework designed to augment our breeding system for the future. This will focus on utilizing emerging technologies from the genome to phenome, as well as a panomics approach with data management and integration to develop, test and incorporate new technologies into a breeding program. In addition to streamlining the breeding pipeline for increased genetic gain, this technology will increase the speed of trait and marker identification for use in genome editing, genomic selection and molecular assisted breeding, ultimately producing novel germplasm that will meet the coming challenges of the 21st Century.

Molecular studies of cellulose synthase supercomplex from cotton fiber reveal its unique biochemical properties

Cotton fiber is a highly elongated and thickened single cell that produces large quantities of cellulose, which is synthesized and assembled into cell wall microfibrils by the cellulose synthase complex (CSC). In this study, we report that in cotton (Gossypium hirsutum) fibers harvested during secondary cell wall (SCW) synthesis, GhCesA 4, 7, and 8 assembled into heteromers in a previously uncharacterized 36-mer-like cellulose synthase supercomplex (CSS). This super CSC was observed in samples prepared using cotton fiber cells harvested during the SCW synthesis period but not from cotton stem tissue or any samples obtained from Arabidopsis. Knock-out of any of GhCesA 4, 7, and 8 resulted in the disappearance of the CSS and the production of fiber cells with no SCW thickening. Cotton fiber CSS showed significantly higher enzyme activity than samples prepared from knock-out cotton lines. We found that the microfibrils from the SCW of wild-type cotton fibers may contain 72 glucan chains in a bundle, unlike other plant materials studied. GhCesA4, 7, and 8 restored both the dwarf and reduced vascular bundle phenotypes of their orthologous Arabidopsis mutants, potentially by reforming the CSC hexamers. Genetic complementation was not observed when non-orthologous CesA genes were used, indicating that each of the three subunits is indispensable for CSC formation and for full cellulose synthase function. Characterization of cotton CSS will increase our understanding of the regulation of SCW biosynthesis.

Recent Progress in Development of Wearable Pressure Sensors Derived from Biological Materials

This review summarizes recent progress in the use of biological materials (biomaterials) in wearable pressure sensors. Biomaterials are abundant, sustainable, biocompatible, and biodegradable. Especially, many have sophisticated hierarchical structure and biological characteristics, which are attractive candidates for facile and ecologically-benign fabrication of wearable pressure sensors that are biocompatible, biodegradable, and highly sensitivity. The biomaterials and structures that use them in wearable pressure sensors that exploit sensing mechanisms such as piezoelectric, triboelectric, piezoresistive and capacitive effects are present. Finally, remaining impediments are discussed to use of biomaterials in wearable pressure sensors.

GhUBX controlling helical growth results in production of stronger cotton fiber

Cotton fiber is an excellent model for studying plant cell elongation and cell wall biogenesis as well because they are highly polarized and use conserved polarized diffuse growth mechanism. Fiber strength is an important trait among cotton fiber qualities due to ongoing changes in spinning technology. However, the molecular mechanism of fiber strength forming is obscure. Through map-based cloning, we identified the fiber strength gene GhUBX. Increasing its expression, the fiber strength of the transgenic cotton was significantly enhanced compared to the receptor W0 and the helices number of the transgenic fiber was remarkably increased. Additionally, we proved that GhUBX regulates the fiber helical growth by degrading the GhSPL1 via the ubiquitin 26S–proteasome pathway. Taken together, we revealed the internal relationship between fiber helices and fiber stronger. It will be useful for improving the fiber quality in cotton breeding and illustrating the molecular mechanism for plant twisted growth.

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Isolation of the first fiber strength gene GhUBX using map-based cloning strategy

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Verification of the function of GhUBX experimentally in transgenic cotton

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Link helices to the cotton fiber strength, that more helices make fiber stronger

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An ubiquitin–proteasome system regulating the development of cotton fiber

Cotton Textile/Iron Oxide Nanozyme Composites with Peroxidase-like Activity: Preparation, Characterization, and Application

At present, both native and immobilized nanoparticles are of great importance in many areas of science and technology. In this paper, we have studied magnetic iron oxide nanoparticles and their aggregates bound on woven cotton textiles employing two simple modification procedures. One modification was based on the treatment of textiles with perchloric-acid-stabilized magnetic fluid diluted with methanol followed by drying. The second procedure was based on the microwave-assisted conversion of ferrous sulfate at high pH followed by drying. The structure and functional properties of these modified textiles were analyzed in detail. Scanning electron microscopy of native and modified textiles clearly showed the presence of iron oxide nanoparticles on the surface of the modified cotton fibers. All of the modified textile materials exhibited light to dark brown color depending on the amount of the bound iron oxide particles. Magnetic measurements showed that the saturation magnetization values reflect the amount of magnetic nanoparticles present in the modified textiles. Small-angle X-ray and neutron scattering measurements were conducted for the detailed structural characterization at the nanoscale of both the native and magnetically modified textiles, and different structural organization of nanoparticles in the two kinds of textile samples were concluded. The textile-bound iron oxide particles exhibited peroxidase-like activity when the N,N-diethyl-p-phenylenediamine sulfate salt was used as a substrate; this nanozyme activity enabled rapid decolorization of crystal violet in the presence of hydrogen peroxide. The deposition of a sufficient amount of iron oxide particles on textiles enabled their simple magnetic separation from large volumes of solutions; if necessary, the magnetic response of the modified textiles can be simply increased by incorporation of a piece of magnetic iron wire. The simplicity of the immobilized nanozyme preparation and the low cost of all the precursors enable its widespread application, such as decolorization and degradation of selected organic dyes and other important pollutants. Other types of textile-bound nanozymes can be prepared and used as low-cost catalysts for a variety of applications.

Faster magic angle spinning reveals cellulose conformations in woods

We present a first report on the detection of three different C6 conformers of cellulose in spruce, as revealed by solid-state 1H-13C correlation spectra. The breakthrough in 1H resolution is achieved by magic-angle spinning in the regime of 150 kHz. The suppression of dense dipolar network of 1H provides inverse detected 13C spectra at a good sensitivity even in natural samples. We find that the glycosidic linkages are initially more ordered in spruce than maple, but a thermal treatment of spruce leads to a more heterogeneous packing order of the remaining cellulose fibrils.

Valorisation of vine shoots for the development of cellulose-based biocomposite films with improved performance and bioactivity

This work reports on the valorization of Tempranillo vine shoots for the development of bio-based packaging materials. Cellulose (F3) and nanocellulose (NANO F3) were produced by the conventional method, while less purified cellulosic fractions (F2A) and nanocrystals (NANO F2A) were extracted by simplified protocols (omitting Soxhlet and alkaline treatments) to reduce production costs and environmental impact and evaluate the potential added functionalities of these less purified materials. Although most of the hemicelluloses in F2A were digested upon acid hydrolysis, a small fraction remained in NANO F2A. On the other hand, the presence of a minor xylan fraction in F3 limited the access of sulphuric acid towards the cellulose microfibrils, hindering hydrolysis and producing heterogeneous fibrillar structures in NANO F3. The obtained materials were used to produce cellulosic films, as well as blends with agar, and their performance properties were evaluated. Overall, NANO F2A films showed the best compromise between performance and sustainability and presented additional antioxidant capacity. The properties of the films could be adjusted by the incorporation of agar, improving their ductility and water permeability.

Zr-MOF modified cotton fiber for pipette tip solid-phase extraction of four phenoxy herbicides in complex samples

Phenoxy herbicides are widely applied in agricultural weeding. The determination of herbicides is important in environmental protection, agricultural production, food safety, and public health. In this study, a facile and efficient analytical method was proposed for the trace detection of phenoxy herbicides in soil, cucumber, and tap water samples by coupling pipette tip solid phase extraction (PT-SPE) with high performance liquid chromatography. UiO-66-funtionalized cotton (Cotton@UiO-66) was packed into pipette-tip as sorbent to fabricate extraction device. The modification of UiO-66 on cotton fiber was confirmed using scanning electron microscope, Fourier transform infrared spectroscopy, and X-ray diffraction. The main factors affecting the adsorption of Cotton@UiO-66 for four phenoxy herbicides were evaluated by response surface methodology in detail. Under optimized conditions, Cotton@UiO-66 displayed excellent properties in the extraction of phenoxy herbicides with good peak shape. Linear ranges of 4-chlorophenoxyacetic acid, dicamba, 2,4-dichlorophenoxyacetic acid, and 2-(2,4-dichlorophenoxy) propionic acid were 1.4-72 μg/L, 5.6-280 μg/L, 2.8-140 μg/L and 3.2-160 μg/L (RSDs < 6.3%), respectively. The recoveries were between 83.3 and 106.8% with RSDs <6.7%, with detection limits ranging from 0.1 μg/L to 0.3 μg/L. The results show that Cotton@UiO-66 in PT-SPE is an effective method for monitoring phenoxy herbicides in complex samples.

Direct Measurement of Plant Cellulose Microfibril and Bundles in Native Cell Walls

Plants use rigid cellulose together with non-cellulosic matrix polymers to build cell walls. Cellulose microfibrils comprise linear β(1,4)-glucan chains packed through inter- and intra-chain hydrogen-bonding networks and van der Waals forces. Due to its small size, the number of glucan chains and their arrangement in a microfibril remains elusive. Here we used atomic force microscopy (AFM) to directly image primary cell walls (PCWs) and secondary cell walls (SCWs) from fresh tissues of maize (Zea mays) under near-native conditions. By analyzing cellulose structure in different types of cell walls, we were able to measure the individual microfibrils in elongated PCWs at the sub-nanometer scale. The dimension of the microfibril was measured at 3.68 ± 0.13 nm in width and 2.25 ± 0.10 nm in height. By superimposing multiple AFM height profiles of these microfibrils, the overlay area representing the cross-section was estimated at 5.6 ± 0.4 nm2, which fitted well to an 18-chain model packed as six sheets with 234432 conformation. Interestingly we found in PCW, all these individual microfibrils could be traced back to a bundle in larger imaging area, suggesting cellulose are synthesized as large bundles in PCWs, and then split during cell expansion or elongation. In SCWs where cell growth has ceased we observed nearly-parallel twined or individual microfibrils that appeared to be embedded separately in the matrix polymers without the splitting effect, indicating different mechanisms of cellulose biosynthesis in PCW and SCW. The sub-nanometer structure of the microfibril presented here was measured exclusively from elongated PCWs, further study is required to verify if it represents the inherent structure synthesized by the cellulose synthase complex in PCWs and SCWs.

Microbial dynamics for lignocellulosic waste bioconversion and its importance with modern circular economy, challenges and future perspectives

An extensive use of microbial dynamics for utilizing the lignocellulosic wastes has been attributed to their efficiency in bioenergy and bioproducts development as a cost effective high nutritional value. The integration of lignocellulosic waste into the circular economy can scaleup the sustainable bioproducts and bioenergy development. In this review paper, the aim is to describe the existing research efforts on organic lignocellulosic waste, cellulase producing microbes, their potential enzyme, modern circular economy with associated challenges and future perspectives. Presently, it has been reviewed that microbial cellulases have provided treasure bioproducts visions into industrial bioproducts marvels unveiled through lignocellulosic waste cutting-edge microbial explorations. Furthermore, the review focused on new insights of the growing circular economy of lignocellulosic waste used for many bioproducts and bioenergy dealings and explored the emergent lignocellulosic biorefinery approaches which could then be applied to review industrial-scale sustainable economic models for upgraded bioproducts and other production associated problems.

Woven cotton yarn-graphene oxide-layered double hydroxide composite as a sorbent for thin film microextraction of nonsteroidal anti-inflammatory drugs followed by quantitation through high performance liquid chromatography

The applicability of a highly flexible and natural cotton yarn-graphene oxide-layered double hydroxide composite (CY-GO-LDH) was introduced for the extraction of the targets in the current study. For increasing the contact area of the analytes and the prepared sorbent, the green substrate was woven and employed as the substrate for the construction of GO layers. It was proved that the prepared CY-GO-LDH film is a reliable sorbent for thin film microextraction (TFME) of the nonsteroidal anti-inflammatory drugs (NSAIDs) including acetylsalicylic acid, naproxen, diclofenac, ibuprofen and mefenamic acid in human urine and plasma. Extraction factors were optimized using multivariate optimization strategy. High adherence of GO-LDH to the natural substrate made this technique more robust for routine analysis. There are two consecutive steps to optimize the parameters influencing the extraction of analytes; First, a Plackett-Burman Design (PBD) was utilized to screen the significant factors. Second, the selected factors were optimized utilizing the Box-Behnken Design (BBD). The extracted NSAIDs were analyzed by HPLC-UV. Under the obtained optimum condition, the linearity of the method was 0.2-200  μg L^-1. Limits of detection, limits of quantification and intra-day as well as inter-day RSDs were lower than 0.25  μg L^-1, 0.72  μg L^-1 and 6.1%, respectively. The method was successfully used to determine NSAIDs in different human biological fluids.

QUOKKA, the pinhole small-angle neutron scattering instrument at the OPAL Research Reactor, Australia: design, performance, operation and scientific highlights

QUOKKA is a 40 m pinhole small-angle neutron scattering instrument in routine user operation at the OPAL research reactor at the Australian Nuclear Science and Technology Organisation. Operating with a neutron velocity selector enabling variable wavelength, QUOKKA has an adjustable collimation system providing source–sample distances of up to 20 m. Following the large-area sample position, a two-dimensional 1 m2position-sensitive detector measures neutrons scattered from the sample over a secondary flight path of up to 20 m. Also offering incident beam polarization and analysis capability as well as lens focusing optics, QUOKKA has been designed as a general purpose SANS instrument to conduct research across a broad range of scientific disciplines, from structural biology to magnetism. As it has recently generated its first 100 publications through serving the needs of the domestic and international user communities, it is timely to detail a description of its as-built design, performance and operation as well as its scientific highlights. Scientific examples presented here reflect the Australian context, as do the industrial applications, many combined with innovative and unique sample environments.