Cellulose最新文献

Bacterial nanocellulose is a promising biomaterial extensively used in functional foods and for drug delivery. Moreover, its characteristics can further be potentialized whether coupled with natural bio-extracts to endow antibacterial activity. Persea americana or avocado seed extracts are rich in phytochemicals and have demonstrated their antioxidant, antimicrobial and enzymatic activities, therefore encapsulating them into bacterial nanocellulose (BNC) may offer a potential release system of antibacterial avocado seed compounds. Accordingly, this study explores the in-depth insight into the influence of different bacterial nanocellulose producing strains (Komagataeibacter hansenii and Komagataeibacter xylinus) and cultivation conditions (static and dynamic cultivation, fermentation time) on the bacterial nanocellulose productivity and characteristics. The obtained bacterial nanocellulose membranes and beads were characterized in terms of chemical structure, morphology and crystallinity. More profitable and productive K. xylinus was further selected for encapsulation (up to 72.89 mg) of avocado seed extracts into bacterial nanocellulose membranes and beads in order to comprehensively evaluate the kinetic release profiles and determine their antibacterial activity against Escherichia coli and Staphylococcus aureus. Results of the study show that the bacterial nanocellulose and avocado seed extracts biohybrids represent a promising immediate (up to 17.39 mg in 1 h) and sustained (up to 35.04 mg in 48 h) release systems. Kinetic release modeling and cytotoxicity assessments confirmed controlled release behavior and biocompatibility for safe antibacterial applications in cosmetics, functional foods and drug delivery.

Understanding bamboo microstructure and fluid transport is essential not only for improving preservative treatments, and bonding performance but also for minimizing cracks during drying and storage after harvest and defining its mechanical characteristics. While various techniques can be applied, nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) remain underexplored for bamboo analysis. In this study, NMR relaxation times effectively distinguished microstructural features of Guadua angustifolia. Three components were identified using the Carr–Purcell–Meiboom–Gill (CPMG) distribution, and two using the Logarithmically distributed Aperiodic-Pulse-Sequence Saturation Recovery (LAPSR) method. Based on the LAPSR distribution, two surface relaxivity values similar to those reported for wood were estimated by correlating with mercury intrusion porosimetry: ρ₁ = 0.067 µm/ms and 0.113 µm/ms for the shorter and longer components, respectively. MRI demonstrated the potential for spatially visualizing water distribution within the bamboo structure under varying moisture conditions. These findings highlight the usefulness of NMR and MRI as non-destructive, non-invasive and fast tools for assessing bamboo microstructure and fluid transport behavior.

Addressing the critical clinical challenge of achieving simultaneous rapid hemostasis and infection prevention in deep, narrow, and irregular non-compressible wounds, this study developed a composite hemostatic sponge using natural mushroom as the substrate. Through alkali treatment to preserve its native polysaccharide 3D network, followed by TEMPO-mediated oxidation and in situ synthesis of ZIF-8 nanoparticles, we constructed a biomaterial featuring a highly interconnected microporous structure that enables remarkable 3 s shape recovery upon hydration. The incorporated ZIF-8 nanocrystals demonstrate dual functionality—significantly accelerating the coagulation cascade while exhibiting potent antibacterial activity against both E. coli and S. aureus pathogens. In vivo evaluation using a rat liver penetrating injury model revealed significantly enhanced hemostatic performance compared to commercial gelatin sponges and Celox™. Comprehensive biosafety assessments confirmed excellent cytocompatibility and hemocompatibility. These combined properties including rapid hemostasis, antimicrobial efficacy, and biocompatibility position ZIF-8@OAM as a promising next-generation multifunctional hemostatic agent for clinical applications.

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Traditional dyeing techniques, which frequently use alkali and inorganic salts, present serious environmental problems, underscoring the need for more environmentally friendly substitutes in the textile sector. In the present study, spun-dyed regenerated cellulosic fibres offer a viable approach that satisfies sustainability goals by lowering environmental effects and improving dyeing uniformity. Using a basic dye-sulfonated polymer complex as the colourant, this work explores a unique method for creating spun-dyed regenerated cellulose fibres (viscose). The complex's potential effectiveness for the spun-dyeing process was demonstrated by its high miscibility and stability within the spinning dope. Compared to traditional reactive dyeing, the developed spun dyed offered a more environmentally friendly alternative by addressing a number of issues with existing dyeing techniques. X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), UV–visible spectroscopy, elemental analysis (CHNS), energy-dispersive X-ray spectroscopy (EDAX), scanning electron microscopy (SEM), tensile testing, optical microscopy, surface charge analysis, and colour intensity measurements were among the various analytical techniques used to characterise the dyed fibres. Optimization of the dyeing process was achieved by determining the ideal concentration of the sulfonated polymer and dye, resulting in fibers with enhanced performance characteristics. The washing fastness of the spun-dyed fibers met the quality standards required for majority of the textile applications. Overall, this study offers insightful information about the creation of extremely colourful spun-dyed viscose fibers, offering a sustainable and environmentally friendly dyeing alternative for cellulosic materials.

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Heavy metal (HM) contamination of agricultural soils poses a significant environmental challenge, threatening crop productivity and ecological health. This study investigated the potential of hydrochar derived from pistachio residues (HC), hydrochar modified with zero-valent zinc nanoparticles (HC-nZVZ), and nZVZ stabilized with carboxymethyl cellulose on hydrochar (HC-nZVZ-CMC) for immobilizing and bioavailability of Pb, Cd, Ni, and Cu in soil cultivated with quinoa. A 60-day pot experiment was conducted under greenhouse conditions with dosages of 1% and 2% (w/w). All amendments significantly enhanced quinoa root and shoot biomass and reduced HM uptake compared to the control (p < 0.05). The HC-nZVZ-CMC treatment exhibited the highest efficacy, increasing root and shoot dry weights by 82% and 87%, respectively, while decreasing metal uptake in shoots and roots by 70–90% and 59–83%. The transfer factor (TF) and bioconcentration factor (BCF) of metals were reduced to below 1 by HC-nZVZ and HC-nZVZ-CMC treatments, indicating decreased metal mobility and bioavailability. Soil pH increased to 8.0 following amendments, accompanied by increases in N, P, K, and SOM content by up to 31%, 39%, 75%, and 54%, respectively, and a reduction in EC by up to 69%. Antioxidant enzyme activities (SOD, CAT, POD) increased by up to 93%, 88%, and 85%, while oxidative stress markers (MDA and H₂O₂) decreased by up to 81% and 74%. indicating reduced oxidative damage. Metal accumulation followed Ni > Cd > Cu > Pb. Stabilizing HC-nZVZ with CMC significantly improved hydrochar’s efficiency, offering a sustainable, cost-effective strategy for remediating heavy metal-contaminated soils.

This study develops biodegradable rice starch-based foams (RSFs), using modified used palm oil (mUPO) as a plasticiser and rice husk (RH), a lignocellulosic agricultural residue containing significant biogenic silica, as a reinforcing filler, both derived from household and agricultural wastes. The RSFs were produced through a simple, low-energy process and exhibited marked improvements in structural integrity, moisture resistance, and thermal stability. Incorporation of mUPO enhanced foam expansion and flexibility, reducing shrinkage from 27.2 to 24.4% and lowering moisture uptake from 5.9 to 1.7%. The addition of RH acted as both a reinforcing and nucleating filler, further refining pore size and raising impact strength from 4.0 to 11.9 J/m at 5 phr (parts per hundered parts of starch by weight). One-way ANOVA with Tukey’s post-hoc test confirmed that the improvements in pore size, shrinkage, and moisture resistance were statistically significant (p < 0.05), validating the combined effect of mUPO and RH. The dual-waste formulation also increased thermal stability and shifted glass transition behaviour, reflecting the complementary roles of plasticisation by mUPO and reinforcement by RH. Overall, the results highlight waste-to-value strategies that transform low-cost secondary products into high-performance RSF, offering promising potential in sustainable packaging, insulation, and lightweight protective materials for the food, logistics, and construction sectors. Among the tested formulations, RSFs containing 6 phr mUPO as plasticiser and 5 phr RH as reinforcement represented the optimum composition, making it particularly promising for eco-friendly packaging, cushioning, and insulation applications where both mechanical robustness and dimensional stability are required.

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This study developed AgNP@BNC liquid SERS substrates using renewable BNC as a green template, addressing the limitations of conventional substrates in stability, eco-friendliness, and scenario adaptability. The three-dimensional nanofiber network of BNC provided uniform nucleation sites for the in-situ reduction of AgNPs and suppressed particle aggregation through physical confinement, generating high-density dynamic hot spots. AgNP@BNC-2 exhibited optimal performance at an analyte-to-substrate volume ratio of 2:1, achieving detection limits of 10⁻¹⁰ M for probe molecules with an enhancement factor of 10⁸–10¹⁰ and excellent signal reproducibility with RSD of 7.2%–7.6%. Finite-difference time-domain simulations have confirmed that the confinement effect of BNC significantly enhances the local electric field intensity in Ag NPs. In complex food matrices (coconut water, soda water), the substrate accurately identified trace sodium saccharin (≥ 10⁻⁷ M, 0.0205 mg/L). This work provides an innovative solution for the green design of liquid SERS substrates and rapid food safety screening.

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Bamboo fibers are considered as promising candidates to replace synthetic fibers in polymer composites, due to their low density, important mechanical properties, and carbon neutrality. During their service life in exigent applications (e.g. structural components near engines, insulation panels, fuselage, and storage compartments), these fibers may be subjected to elevated temperatures that can alter their multiphysical properties. Interestingly, the high temperatures required during the manufacturing of fiber-reinforced thermoplastic composites also call for a thorough understanding of the physico-chemical, microstructural, and mechanical properties of these fibers over a wide temperature range. For this reason, the goal of this study was to examine the thermal aging effects on the physico-chemical, microstructural, sorption, and mechanical properties of bamboo fibers. The ultrastructural changes induced by thermal aging were analyzed using infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD), and scanning electron microscope (SEM). The main results revealed that exposure to high temperatures, ranging from 60 to 220 °C, induces the development of cracks, voids, and structural changes, including the occurrence of thermochemical reactions, which lead to a reduction in tensile strength. The sorption isotherms of bamboo fibers were also analyzed by dynamic vapor sorption (DVS) at different temperatures (20, 40, and 60 °C). The findings indicated that the equilibrium moisture uptake increases with relative humidity, while the increase in temperature limits moisture absorption. Interestingly, the moisture diffusion kinetics were modelled using classical Fickian diffusion, the dual-stage Fickian approach, and the Langmuir-based model. Herein, the dual-stage Fick and Langmuir models accurately predict the experimental data, highlighting the anomalous diffusion in fibers at various environmental conditions. This research provides critical insights into the durability of bamboo fibers under different thermal conditions.

Biopolymer-based materials derived from agricultural waste offer sustainable and functional alternatives for material development. Cellulose was extracted from palm kernel shells via alkaline treatment and delignification, yielding 30.10% cellulose. The extracted cellulose was used to synthesize carboxymethyl cellulose (CMC), achieving a maximum degree of substitution of 0.73 and a yield of 79.73% with 4 g of monochloroacetic acid. The CMC films were then modified using citric acid as a crosslinking agent, glycerol as a plasticizer, and the freeze–thaw (FT) method, resulting in improved mechanical flexibility (elongation at break increased from 42.00 ± 6.88% to 45.00 ± 5.32%) and reduced water vapor permeability (from 2.13 ± 0.08 to 1.70 ± 0.15 × 10⁻¹⁰ g·m⁻¹·s⁻¹·Pa⁻¹), indicating enhanced film compactness. MOFs serve as effective adsorbents, with bio-MOFs offering the additional advantage of biocompatibility. Among the composite films, β-CD-Cu@CMC exhibited moderate antibacterial activity against Staphylococcus aureus and maintained its effectiveness for several days. Furthermore, β-CD-Cu@CMC demonstrated effective ethylene adsorption, reducing the residual ethylene from 30 to 26.27% within 120 min, and significantly delaying banana ripening. These findings highlight the multifunctional potential of the β-CD-Cu@CMC films for sustainable packaging applications. β-CD-Cu has significant potential as a biocompatible and effective material for ethylene adsorption, with opportunities for further advancement through targeted modification.

The comprehensive implementation of sustainable development strategies has brought the preservation of cultural relics to the forefront, necessitating advanced electronic systems capable of real-time monitoring of temperature and humidity conditions for these invaluable artifacts. To address the critical gap in real-time ambient environmental monitoring for cultural relics, we present a self-powered nanopaper-based sensor system with exceptional performance characteristics: precise temperature monitoring (± 2 °C accuracy) and reliable humidity detection (± 5% accuracy) in real-time, combining merits of high sensitivity, rapid response, long-term durability, and eco-friendly materials, specifically engineered to meet the stringent requirements of cultural relic conservation. In addition to substantial power consumption reduction, the triboelectric nano-generator (TENG), inducing by triboelectricity between human’s skin and the nanopaper, enables the device anti-theft capabilities. The outstanding comprehensive performance of our sensing array establishes a promising foundation for the development of self-powered sensors in the field of heritage conservation.