Search Results (1,014)

The production and use of plastics have direct consequences on the environment, such as the greenhouse gas emissions (GHGs) they cause. Therefore, it is necessary to develop materials from renewable sources with a lower environmental impact to replace plastic. In this work, films with bioactive properties have been developed from cellulose nanofibers (CNFs) and natural phenolic compounds for food packaging applications. First, the optimization of the incorporation of three different natural phenolic compounds (tannic acid, p-coumaric acid, and acetosyringone) into nanocellulose was studied using a Box–Behnken design, with the phenols adsorbed by the nanocellulose as the output variable. Once the incorporation was optimized, films containing nanocellulose and phenolic compounds were produced and characterized. Tannic acid showed the best results with regard to the optical properties of the resulting films and achieved a complete blocking of UV-B radiation, as well as adding to nanocellulose antioxidant (4.32 mM TE/g film) and antibacterial capacity (log R of 6.6 ± 0.2 and 3.8 ± 0.1 for Staphylococcus aureus and Escherichia coli, respectively), making these films a promising material for use in contact with food as a packaging material, although more in-depth studies and measures are needed to make these films viable for use in food packaging. Full article

This study investigates the valorisation of Salicornia ramosissima agro-industrial by-product by using cellulose nanofibers (CNFs) extracted from this halophyte to reinforce chitosan-based films. The physical, mechanical, and thermal properties of chitosan films containing 0% (control), 1%, and 2% (w/w) CNF were evaluated. Films were produced by solvent casting with glycerol as a plasticiser. At the 2% CNF concentration, films exhibited a reduced moisture content and increased solubility in aqueous solutions. The water vapour transmission rate (WVTR) decreased as CNF content increased under constant humidity but increased at higher temperature and humidity. Control films were more transparent, yet CNF-reinforced films had higher tensile strength and Young’s modulus, reflecting greater stiffness. Maximum elongation at break decreased markedly with the addition of CNFs. SEM revealed that reinforced films had more heterogeneous, rougher surfaces, particularly at 2% CNF. Thermogravimetric analysis showed that 2% CNF adversely affected the thermal stability of the chitosan film. ATR-FTIR spectra indicated that CNF reinforcement protected against UV-induced degradation. Degradability tests in soil and seawater confirmed that the chitosan–CNF mixture preserved degradability, especially at 1% CNF. These findings demonstrate that reinforcing chitosan-based films with CNFs from S. ramosissima can improve functional properties and suggest the potential of this approach for biomaterials development in food packaging applications. Full article

Carbon-based bifunctional oxygen electrocatalysts with rationally designed architectures are essential for high-performance rechargeable zinc–air batteries (ZABs), yet the concurrent optimization of catalytic activity, durability, and mass transport remains challenging. Herein, hierarchical ZnCo carbon nanofibers/carbon nanotubes (CNFs@CNTs) are fabricated via single-nozzle electrospinning followed by melamine-assisted pyrolysis under a ZnCl₂-regulated atmosphere. During thermal treatment, Co species embedded within carbon nanofibers catalyze in situ carbon nanotube growth, while ZnCl₂ vapor modulates the carbonization process and surface chemistry, collectively generating a hierarchical CNFs@CNTs architecture with high surface area and abundant exposed active sites. As a result, ZnCo CNFs@CNTs exhibit outstanding bifunctional ORR/OER activity, surpassing Zn-free and Co-free counterparts. Combined structural and electrochemical analyses reveal that the synergistic interaction between Co active centers and Zn-assisted carbon structural regulation enhances reaction kinetics and long-term stability. When implemented as air electrodes in rechargeable ZABs, ZnCo CNFs@CNTs deliver high power density, reduced charge–discharge polarization, and excellent cycling durability, demonstrating strong practical applicability. This work presents an effective strategy for constructing hierarchical CNFs@CNTs composites via electrospinning and dual-component thermal regulation, offering new insights into the design of high-efficiency bifunctional air electrodes for advanced ZABs. Full article

Nanocellulose materials (CNMs), encompassing cellulose nanocrystals (CNCs), cellulose nanofibrils (CNFs), and bacterial nanocellulose (BNC), have emerged as a versatile and sustainable class of bio-based nanomaterials with significant promise for applications in mechanical engineering. This review systematically examines the processing of nanocellulose via mechanical, chemical, and enzymatic routes, alongside surface modification strategies that enhance performance and address scalability challenges. A principal advantage of CNMs lies in their exceptional mechanical properties, including superior strength, stiffness, and toughness, which position them as high-performance, sustainable reinforcement agents for advanced composites. Beyond mechanical reinforcement, CNMs exhibit a suite of functional properties critical for engineering design, such as thermal stability, tunable conductivity, effective gas/moisture barrier performance, and improved tribological behavior. These characteristics enable their use in diverse high-value applications, including lightweight composites, protective coatings, energy storage devices, sensors, actuators, and intelligent material systems. Furthermore, the inherent renewability, biodegradability, and recyclability of nanocellulose align closely with the principles of a circular economy and green engineering. However, the successful integration of CNMs into mainstream manufacturing requires overcoming key challenges. These include the energy intensity of certain production processes, inherent moisture sensitivity, long-term stability under operational conditions, and compatibility with established industrial techniques. Life-cycle analyses reveal important environmental trade-offs that must be navigated. Overall, nanocellulose represents a renewable, multi-functional material platform whose unique combination of mechanical performance, functional versatility, and environmental benefits is poised to drive innovation in next-generation engineering materials. Full article

This study investigates the development of polyvinyl alcohol (PVA)-based nanocomposite films reinforced with cellulose nanofibrils (CNFs) and biobased additives derived from blueberry pruning waste for sustainable food packaging applications. The nanocomposites were fabricated via solvent casting and evaluated in terms of their thermal and antimicrobial properties. Thermogravimetric analysis (TGA/DTG) revealed that the thermal degradation of the nanocomposites occurs through overlapping processes of PVA and CNFs, with maximum degradation temperatures ranging from 273 to 293 °C depending on the formulation. The incorporation of CNFs modified the degradation pathway and promoted the formation of thermally stable carbonaceous residues, while TEMPO-oxidized samples exhibited a decrease in degradation onset (14–24 °C) due to the presence of oxidized surface groups. Remarkably, the nanocomposites exhibited significant antimicrobial activity against both Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria without the incorporation of external antimicrobial agents. Bleached PVA/CNFs films achieved complete growth inhibition (100%), while lignin-containing and additive-modified systems showed selective antibacterial behavior. Zeta potential analysis confirmed a negatively charged CNF surface (−35.3 mV), which may contribute to electrostatic interactions with bacterial membranes. Scanning electron microscopy (SEM) revealed nanostructured surfaces with exposed fibrillar networks that promote bacterial adhesion and immobilization, supporting a contact-active antimicrobial mechanism. These findings demonstrate that the antimicrobial performance of PVA/CNFs nanocomposites is governed by intrinsic physicochemical and topographical properties rather than by the release of antimicrobial agents. This approach provides a safer and more sustainable strategy for the design of active food packaging materials. Full article

Background: Disease outbreaks remain a major constraint on aquaculture production, making vaccination essential for disease management in farmed fish. However, injectable oil-adjuvanted vaccines can be costly and may induce adverse inflammatory reactions and welfare concerns, motivating investigations into alternative injectable adjuvant materials. Methods: We conducted an in vivo safety evaluation of shear-thinning, amidated TEMPO-oxidized cellulose nanofiber (TO-CNF) hydrogels formulated with an inactivated Vibrio anguillarum bacterin. Formulations were administered intraperitoneally to Atlantic salmon (Salmo salar L.) using a common garden design with cohabitated treatment groups across triplicate tanks. Fish were monitored and sampled at pre-injection baseline and at 300-, and 600-degree days post-injection. Safety endpoints included mortality, macroscopic and histopathological outcomes, and growth evaluated relative to sham controls, unmodified TO-CNF, and a commercial oil-adjuvanted vaccine. Results: Amidated TO-CNF formulations were associated with increased mortality (up to 16–18% in higher reagent-loading groups) compared to commercial oil-adjuvanted vaccine, material, and sham controls. Affected fish exhibited adverse outcomes, including adhesions, proliferative lesions, ascites, edema, hemorrhage, and secondary opportunistic infections. In contrast, controls showed minimal mortality and pathology. Growth and immune response endpoints were variable and did not demonstrate consistent treatment-associated effects. Physicochemical analyses indicated differences in formulation stability and qualitative compositional differences across modification levels, but these were not quantified nor linked to specific causal mechanisms in this study. Conclusions: The amidated TO-CNF formulations tested here were associated with formulation-dependent safety risks under the conditions evaluated and are not yet suitable as injectable vaccine adjuvants in Atlantic salmon. These findings define important safety constraints for this material class and highlight the need for improved modification and purification strategies. More broadly, this work underscores the importance of establishing in vivo safety boundaries prior to efficacy optimization for emerging biomaterial-based vaccine adjuvants. Full article

Benefiting from their outstanding porosity, considerable specific surface area, and natural flexibility, cellulose nanofibers (CNFs)/MOF materials have emerged as competitive candidates for advanced flexible energy storage devices. However, conventional CNFs/MOFs aerogels or films often suffer from poor recoverability under compression, bending, and folding, accompanied by severe plastic deformation that compromises the cycling and structural stability of devices. To address this issue, we report a rationally designed flexible PU/CNFs/ZIF-8/PANI composite foam with an interconnected micro-mesoporous structure. Using polyurethane foam as a soft substrate and CNFs/ZIF-8 as building blocks, the composite was fabricated through a combined strategy of impregnation, in situ ZIF-8 growth, hot-pressing, and in situ aniline polymerization with simultaneous etching of the ZIF-8. The incorporation of carboxylated CNFs enhances the hydrophilicity of the PU skeleton. This, in combination with the hot-pressed framework, establishes an interconnected 3D network, thereby effectively preventing the agglomeration of active materials. Meanwhile, the hierarchical pores derived from the sacrificial ZIF-8 template provide abundant electroactive sites, accelerate ion transport, and facilitate high PANI loading. By virtue of this synergistic architectural effect, the resultant electrode achieves a high specific capacitance of 449 F/g at 0.2 A/g, with 97% capacitance retention after 2000 cycles at 5 A/g. Furthermore, the composite foam demonstrates excellent mechanical flexibility, with a tensile strength of 0.87 MPa and an elongation at break of 230%. This work offers a feasible approach for developing high-performance flexible supercapacitors and provides novel perspectives for the rational design of portable energy storage devices. Full article

Voltage sags pose severe risks to sensitive equipment in modern industries, requiring power quality monitoring equipment to possess fast and accurate sag detection capabilities. The traditional second-order generalized integrator (SOGI) will have oscillation phenomena in the case of DC offset, low-frequency harmonics, and high-frequency impulse noise. This study introduces a strong detection algorithm that combines Adaptive Composite Morphological Filtering (ACMF) with an improved Mixed Second- and Third-Order Generalized Integrator (MSTOGI). First, the ACMF pre-filtering module dynamically adjusts the scale of composite structuring elements through periodic parameter optimization, effectively filtering high-frequency random impulses while preserving the sharp transitions of abrupt voltage changes. Second, MSTOGI eliminates DC offset, and optimizes the gain coefficient to achieve the best dynamic response speed. Ultimately, a cascaded notch filter (CNF) module focuses on and removes even-order harmonic ripples caused by the synchronous reference frame transformation. Simulation results indicate that under severe grid conditions involving multiple composite distortions, the proposed architecture reduces the sag detection time to within 1.0 ms under typical operating conditions, with steady-state phase errors strictly controlled within a ±2° range. This method provides a reliable solution for DVR and UPS. Full article

Cellulose nanofiber (CNF)–boron nitride nanotube (BNNT) composite separators have been widely investigated; however, many demonstrations rely on BNNT pretreatment or multistep processing to secure dispersion and integration. HwBKP-derived CNF separators (HCNF), based on an enzymatically pretreated and turbulence-flow nanomill processed CNF suspension, were combined with BNNTs without pretreatment to fabricate BNNT-incorporated composite membranes (HBNT-05 and HBNT-10) via a simple stirring–filtration–drying route. The CNF suspension and membranes were characterized by fibril image analysis, SEM, AFM, FTIR, and XRD, together with wettability and surface free-energy measurements, to examine BNNT-loading-dependent changes in separator structure and surface microtexture. When evaluated in NCM811||Li half-cells, the BNNT-incorporated membranes exhibited composition-dependent electrochemical performance trends relative to the BNNT-free CNF membrane, while the commercial polyolefin reference remained favorable at the highest tested C-rate. These results suggest that the present fabrication route enables effective BNNT incorporation without BNNT pretreatment under the studied conditions, providing a practical strategy to tune biomass-derived CNF membranes for energy-storage applications. Full article

The inherent hydrophobicity of polyolefin separators significantly impedes rapid electrolyte wetting, thereby limiting the electrochemical performance of lithium-ion batteries. Cellulose, as a hydroxyl-rich natural polymer, serves as an ideal material for enhancing the interface properties of separators. However, there is still a lack of systematic understanding regarding how the morphological structures of cellulose (such as granular, fibrous, or network-like forms) influence the coating structure and ion transport mechanisms. Here, three representative cellulose derivatives—microcrystalline cellulose (MCC), cellulose nanofibers (CNF), and bacterial cellulose (BC)—were selected to construct functionalized polypropylene (PP) composite separators through vacuum filtration. Experimental results demonstrate that all three cellulose coatings reduced contact angles from 50.8° to below 10°, significantly enhancing interfacial affinity. Systematic comparison reveals that cellulose configuration decisively influences separator performance: unlike the dense fiber entanglement networks formed by CNF and BC, the unique rigid granular packing structure of MCC maintains hydrophilicity while establishing more permeable ion transport pathways. Among these, MCC@PP exhibited optimal electrochemical performance, with the lithium-ion migration number increasing to 0.41 and a capacity retention rate of 88.04% after 100 cycles at 0.5 A/g. This study elucidates the relationship between cellulose configuration and the modification of separator performance, demonstrating that MCC represents a more efficient, robust, and cost-effective option for separator modification compared to complex fiber networks. Full article

Developing advanced functional materials requires the synergistic integration of nanoscale reinforcements with tailored properties. In this work, composite films of cellulose nanocrystals (CNCs), cellulose nanofibrils (CNFs), and reduced graphene oxide (rGO) were synthesized using a combination of solution casting, high shear homogenization, vacuum filtration, and environmentally friendly chemical reduction. The resulting CNC/CNF/rGO films exhibited a robust hierarchical structure with strong interfacial interactions, enabling exceptional mechanical properties, specifically a tensile strength of 215 MPa and a Young’s modulus of 18 GPa, alongside a continuous conductive network confirmed by frequency-independent electrical conductivity up to 30 kHz. Comprehensive dielectric characterization revealed frequency-dependent permittivity and low dielectric loss, aligning with Maxwell–Wagner theoretical predictions for heterogeneous composites. The composites also demonstrated thermal stability, with electrical conductivity increasing monotonically from 0 °C to 200 °C. These findings highlighted the CNC/CNF/rGO films’ suitability for applications in flexible electronics, electromagnetic shielding, packaging, and high-performance structural materials. Future optimization and modeling approaches, including fractional calculus, are recommended to further enhance multifunctionality and exploit the unique synergistic interactions intrinsic to nanocellulose–graphene oxide platforms. Full article

The valorization of agro-industrial byproducts as sources of functional polysaccharides is a promising strategy for developing sustainable materials. In this study, cellulose was extracted and purified from rice husk and apple pomace through sequential alkaline and bleaching treatments. Then it was chemically modified via TEMPO-mediated oxidation to obtain cellulose nanofibers (TOCNFs) with cellulose yields ranging from 23.8 to 32.4% for rice husk and 9.3–13.8% for apple pomace. Owing to its higher recovery and structural regularity, rice husk was selected for surface modification with 3-aminopropyltriethoxysilane (APTES). The resulting TOCNFs exhibited an average width of 8 nm and a carboxyl content of 0.48 mmol g⁻¹. Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and nitrogen determination (1.72 mg g⁻¹) confirmed the presence of aminosilane functionalities. APTES-modified TOCNFs were incorporated as active components to develop hybrid poly(vinyl acetate) (PVA) adhesives synthesized via in situ heterogeneous water-based polymerization. The influence of TOCNF surface chemistry and sodium dodecyl sulfate (SDS) on latex particle size, rheological behavior, and adhesive performance was systematically investigated. Latex particle size increased from 193 nm (PVA-SDS) to 625 nm with TOCNF-APTES and decreased to 247 nm upon SDS addition. Rheological analysis revealed pronounced shear-thinning behavior associated with the formation of percolated nanofibrillar networks, with low-shear viscosity increasing up to 477 Pa·s for TOCNF–APTES and decreasing to 370 Pa·s with SDS. Lap-shear testing (ASTM D905) showed substantial improvements in adhesive strength, reaching up to 250 kPa compared to PVA-SDS. These results demonstrate that surface-modified CNFs act not only as mechanical reinforcements but also as interfacially active components governing polymerization behavior, rheology, and adhesive performance. This exploratory study provides a proof-of-concept for the development of sustainable wood adhesives from agro-industrial byproducts. Full article

Flexible supercapacitors have attracted significant attention as promising power sources for portable and wearable electronic devices. However, achieving simultaneous high power density, energy density and long-term cyclic stability in a simple device configuration remains a critical challenge. Herein, we report an all-solid-state flexible planar supercapacitor based on hierarchically structured cellulose nanofiber-carbon nanotube@manganese dioxide (CNF-CNT@MnO₂) composite aerogels. The electrode architecture is rationally designed by first dispersing CNTs within a hydrophilic CNF scaffold to form a conductive three-dimensional network, followed by in situ oxidative polymerization of MnO₂ onto the CNF-CNT fibrous skeleton. The hydrophilic CNFs network ensures thorough electrolyte penetration, the interconnected CNTs facilitate rapid electron transport, and the uniformly coated MnO₂ layer provides substantial pseudocapacitance. The aerogel electrode with a low density of 14.6 mg cm⁻³ and a high specific surface area of 214.4 m² g⁻¹ delivers a specific capacitance of 273.0 F g⁻¹ at 0.4 A g⁻¹. The assembled planar supercapacitor, incorporating gel electrolyte and a flexible hydrogel substrate, achieves an impressive areal capacitance of 885.0 mF cm⁻² at 2 mA cm⁻², energy density of 122.9 μWh cm⁻² and corresponding power density of 1000.0 μW cm⁻². The device exhibits excellent electrochemical stability, retaining 83.3% capacitance after 2500 charge–discharge cycles, and outstanding mechanical flexibility, with 96.3% capacitance retention after 200 repeated bending cycles. Furthermore, multiple devices can be connected in series or parallel to proportionally increase output voltage or current, meeting the practical power requirements of electronic applications. This work offers a viable pathway toward high-performance, durable energy storage solutions for next-generation wearable electronics. Full article

This study used a 3-year field experiment to evaluate the effects of controlled-release nitrogen fertilizers (CRNFs) on rice yield, nitrogen (N) uptake, N recovery efficiency (NRE), N agronomic efficiency (NAE), N partial factor productivity (NPFP), and soil nutrients under straw-returning (SR) conditions in the black soil region of Northeast China. The results showed that CRNF combined with SR increased rice yield, NRE, NAE, and NPFP by 11.2%, 27.7%, 26.1%, and 22.3% respectively; the differences were significant when compared with common N fertilizer (CNF) combined with SR. In addition, CRNF increased soil organic matter (SOM), total N (TN), available N (AN), and other nutrients while reducing nitrate N (NO₃⁻-N) accumulation in the 30–60 cm soil layer. When the N application rate was reduced by 12%, rice yield still increased by 4.7%, and NRE, NAE, and NPFP increased by 17.2%, 32.9%, and 11.7% respectively; the differences were significant, and the content of soil nutrients has increased to varying degrees. These results indicate that a one-time basal application of controlled-release urea (CRU) mixed with bare urea (BU) at a 6:4 ratio can maintain stable yields, improve fertilization efficiency, reduce N fertilizer input, and lower environmental risks. Therefore, this approach represents an effective strategy for sustainable fertilization in rice-growing areas of Northeast China. Full article

As photovoltaic modules advance toward higher efficiency, environmental sustainability and carbon emission reduction in materials have become important issues. In this study, large-area transparent films were fabricated using TEMPO-oxidized cellulose nanofibers (CNFs), and their feasibility as replacements for conventional petroleum-based polymer films in photovoltaic module materials was evaluated. The CNF films were stably fabricated under large-area processing conditions with uniform thickness. The CNF films exhibited high optical transmittance in the visible region comparable to commercial polymer films, sufficient mechanical stiffness, and thermal stability under module lamination conditions. Module-level performance analysis showed that the effect of CNF film application depended on the application position, with different output trends for front and rear configurations. These results demonstrate the potential of large-area CNF films as sustainable photovoltaic module materials and their contribution to carbon emission reduction through the use of renewable bio-based resources. Full article