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[Display omitted] • Cellulose nanofiber/molybdenum disulfide aerogels. • CNF/MoS 2 aerogels deliver an ultrahigh temperature output up to 260.4 °C. • Aerogels began to burn, achieving the superhigh surface temperature of ∼ 690 °C. • The combustion process of CNF/MoS 2 composite aerogels was evaluated in detail. The photothermal materials have a broad range of applications in crude oil spills treatment, desalination, and photothermal therapy. However, the rational construction of aerogels with exceptional photothermal performance is highly desired yet still challenging. Herein, a class of stable aerogels comprised of molybdenum disulfide (MoS 2) nanoflowers and cellulose nanofibers (CNFs) was fabricated, affording extraordinary light-to-heat energy conversion capability. Benefiting from the intercalated porous structure, the resultant cellulose nanofibers/molybdenum disulfide (CNF/MoS 2) aerogels deliver an ultrahigh temperature output up to 260.4 °C with near infrared (NIR) laser power densities of 0.8 W cm−2. Remarkably, when NIR laser power density increased to 1.0 W cm−2, the aerogels began to burn, achieving the superhigh surface temperature of ∼ 690 °C. The combustion process of CNF/MoS 2 composite aerogels was evaluated in detail. Therefore, this work provides experiment evidence and theoretical basis for the rational applications of photothermal materials at high temperature in future. [ABSTRACT FROM AUTHOR]

In this study, a green, highly efficient and low energy consumption preparation method of cellulose nanofiber (CNF) was developed by using agricultural and forestry waste durian rinds as raw materials. The power of ultrasonic treatment was successfully reduced to only 360 W with low molecular weight liquid DMSO. The obtained durian rind-based CNF had a diameter of 8–20 nm and a length of several micrometers. It had good dispersion and stability in water, and could spontaneously cross-link to form hydrogel at room temperature when the concentration was more than 0.5%. The microscopic morphology and compressive properties of CNF aerogels and composite cellulose aerogels prepared from durian rind-based CNF were evaluated. It was found that CNF could effectively prevent the volume shrinkage of aerogel, and the concentration of CNF had a significant effect on the microstructure and mechanical properties of aerogel. The CNF aerogel with 1% CNF exhibited a sheet structure braced by fibers, which had the strongest compression performance. The porosity of CNF aerogels was high to 99%. The compressive strength of the composite cellulose aerogel with durian rind-based CNF was effectively enhanced. [ABSTRACT FROM AUTHOR]

The introduction of nanofillers into conventional microsized fiber-reinforced plastic composites has great potential to improve the fracture toughness and crystalline properties of composites, especially for semicrystalline thermoplastic polymers. Although the selective reinforcement is possible by nanofiller addition, the influence of the addition position of nanofillers on the mechanical properties and crystalline properties still has not been revealed. In this work, the cellulose nanofibers (CNFs) as the secondary filler were added (i) into a polypropylene (PP) matrix by a melt-mixing process and (ii) onto a carbon fiber (CF) surface by a dip-coating process in a CF-reinforced PP composite. By focusing on the transcrystals surrounding CFs, which enable improvement of the interfacial strength, the crystalline properties and mechanical properties were investigated through polarized optical microscopy, differential scanning calorimetry, X-ray diffraction, and 3-point bending tests in this study. We revealed that (i) CNF addition into the PP matrix disturbed the transcrystallization surrounding CFs and that the mechanical properties slightly decreased. Conversely, (ii) CNF addition onto the CF surface promoted transcrystallization surrounding the CF, and the flexural yield strength and modulus significantly improved by a maximum of 30% and 63%, respectively. [ABSTRACT FROM AUTHOR]

Rubber/nanocellulose composite sheets improve tensile properties compared with neat rubber sheets, when nanocellulose materials are suitably compounded with rubber matrices. First, two oven‐dried nanocellulose materials containing different additive components were prepared from nanocellulose/water dispersions, and the oven‐dried nanocellulose‐containing materials were compounded with rubber sheets under high shear forces by using a two‐roll mill. The tensile moduli and strength of the rubber/nanocellulose composite sheets were clearly better than those of the rubber sheet prepared without nanocellulose, while the elongations at break were similar. Thin films were cut from the rubber/nanocellulose composite sheets, and their real‐time tensile deformation processes were observed by transmission electron microscopy (TEM) to understand the time‐dependent patterns of crack propagation, void formations, and fusion between cracks and voids in the composites during tensile deformation. TEM observations showed that the composite sheets consisted of individual rubber/nanocellulose clusters. Voids initially formed inside the rubber/nanocellulose clusters, propagated to form cracks, fused with other voids or secondary cracks. There were slight differences between the crack‐propagation patterns of the two rubber composites, probably because of differences in the morphologies, sizes, distributions, and structures of the rubber/nanocellulose clusters, and surface chemical structures of individual nanocellulose elements between the composites. [ABSTRACT FROM AUTHOR]

A short-length cellulose nanofiber (CNF) aqueous sol, prepared by a high-pressure homogenizer, showed a rapid longer relaxation time (T2) in the low-field 1H-nuclear magnetic resonance (NMR) when diluted from 20 wt% to 1 wt%. Magnetic stirring for 30 min disentangled the fiber networks and the fragmented fibers appeared in the 1 wt% CNF sol. A decrease in the specific viscosity of the diluted sols changed the rheological behavior from exponential to linear below 1 wt%, suggesting a significant decrease in the inter-fibril interaction. The small angle x-ray scattering (SAXS) with the generalized indirect Fourier transformation (GIFT) also indicated similar changes in the fiber flocculation structure without a change in the fiber size. The increasing viscosity upon severe fiber fragmentation by a high-pressure homogenizer may be ascribed to tighter holding of the interfibril water molecules. The time-domain (TD)-NMR fully supported the estimation that the transverse relaxation time (T2) showed consistently short for the 2 wt%, became shorter with the stirring time when diluted from 5 wt% to 2 wt%, and showed long upon dilution from 20 wt% to 2 wt%. Understanding the complex behavior of the highly viscous CNF sols during a simple dilution process may pave the way for developing CNF-related technology. [ABSTRACT FROM AUTHOR]

Cellulose, the most abundant sustainable material on Earth, has excellent mechanical and physical properties, high optical transparency, biocompatibility, and piezoelectricity. So, it has many possibilities for future materials, and many researchers are interested in its application. In this paper, cellulose nanofiber (CNF) and CNF/polyvinyl alcohol (PVA) films are made, and their vibration energy harvesting is studied. CNF was isolated by chemical and physical methods, and the CNF suspension was cast on a flat substrate to make a film. A cast CNF wet film stayed in a 5 Tesla superconductor magnet for 7 days, which resulted in CNF alignment perpendicular to the magnetic field. To further improve the mechanical properties of the CNF film, mechanical stretching was applied. The CNF suspension was mixed with PVA, giving the film toughness. The cast CNF/PVA wet film was mechanically stretched and dried, which improved the CNF alignment. The fabricated CNF and CNF/PVA films were characterized using scanning electron microscopy and X-ray diffraction to verify the alignment. By stretching, the aligned CNF/PVA film exhibits the largest mechanical properties along the aligned direction. The maximum Young's modulus and tensile strength of the 50% stretched CNF/PVA film are 14.9 GPa and 170.6 MPa, respectively. Finally, a vibration energy harvesting experiment was performed by invoking the piezoelectric behavior of the pure CNF, and 50% stretched CNF/PVA films. The harvester structure was innovated by adopting a cymbal structure, which was beneficial to producing large in-plane strain on the films. The designed cymbal structure was analyzed using ANSYS, and its natural frequency was experimentally verified. The CNF/PVA film performs better vibration energy harvesting than the pure CNF film. The CNF/PVA film is applicable for biocompatible and flexible vibration energy harvesting. [ABSTRACT FROM AUTHOR]

Cellulose nanofibers (CNF) were isolated from raw cotton fibers via 2, 2, 6, 6-tetramethylpiperidine-1-oxyl (TEMPO) oxidation process. The isolated CNF were morphologically characterized using Field Emission Scanning Electron Microscopy (FESEM) and Transmission Electron Microscopy (TEM). Entangled fibrous morphology with diameter in nano regime (15–20 nm) has been observed for the isolated nanofibers. X-ray diffraction (XRD) analysis confirms the high crystallinity of the isolated CNF. Further, the isolated CNF was used to reinforce natural rubber (NR) latex films. The crystallographic, morphological, and spectroscopic analysis of the NR/CNF nanocomposites was carried out. A strong interaction between the CNF and NR matrix has been identified and which reflects in the thermal stability and swelling behavior of NR/CNF nanocomposite films in toluene. The uniform dispersion and tangling effect of CNF along with strong NR-CNF interaction restrict the uptake of solvent through NR matrix. [ABSTRACT FROM AUTHOR]

We investigated the mechanical properties of corn starch (CS)/poly(vinyl alcohol) (PVA)/borax hydrogels reinforced by clay platelets, silica (SiO2) nanospheres, or cellulose nanofibers (CNFs). The effects of these reinforcing agents on the tensile properties of the hydrogels were quite different; the fracture stress of SiO2/CS/PVA/borax composite hydrogels increased with SiO2 concentration, whereas that of clay/CS/PVA/borax composite hydrogels was high at a low clay concentration but low at high clay concentrations; for CNF/CS/PVA/borax composite hydrogels, although the elastic modulus was highly enhanced by adding CNF, the fracture stress was very low because of the stress relaxation during the elongation. This result came from differences in the dispersibility of each filler and the reinforcing ability. These composite hydrogels were constructed by multi-crosslinking, such as hydrogen bonding between CS and PVA, CS and PVA crystals, complexation between borate and PVA (partly CS), and the crosslinking between each filler and polymer. The self-healing ability of SiO2 and clay composite hydrogels was examined. As a result, the SiO2/CS/PVA/borax composite hydrogels possessed an excellent self-healing ability, whereas the clay/CS/PVA/borax composite hydrogels had a poor self-healing ability. [ABSTRACT FROM AUTHOR]

In this study, carbon dot (CD) was in-situ synthesized on cellulose nanofiber (CNF) surface by simple one-step hydrothermal carbonization. Based on the analyses of chemical structure and photoluminescence characteristics, we changed the electron pathway of carbon dot by controlling the CNF concentration in the composite. The electronic stabilization of CNF was observed in the composites from low CNF concentrations. Meanwhile, with high CNF concentrations, electrons were barely transferred to CNFs but recombined radiatively. Aggregation-induced blue-shifted emission occurred in the solid-state composite films without significant changes in the electron relaxation pathways. This study provides valuable insights into the electron relaxation pathway of the fabricated composite, which may be helpful in the design and economical fabrication of CD-based advanced optical devices. [ABSTRACT FROM AUTHOR]

To overcome the drawbacks of homopolymer-grafted CNF one-component nanocomposites, a range of diblock-grafted cellulose nanofiber (CNF), CNF-g-(polybutyl acrylate-b-polymethyl methacrylate)s were synthesized through reversible-deactivation radical polymerization (RDRP) methods. The chemical structures and ratios between the two blocks were confirmed, with surface-grafted CNF observed as submicron particles. Both thermal and thermodynamic analysis revealed two glass transition temperatures (T g ) in the diblock-grafted CNF, and phase-separated morphology was observed in the nanocomposites. The densely grafted CNF displayed island structures, while sparsely grafted samples transitioned into continuous structure. Thermodynamic analysis showed that the diblock-grafted CNF nanocomposites maintained mechanical properties at high temperatures. These nanocomposites demonstrated robust strength and toughnes, with tensile strength reaching as high as 43.7 ± 1.6 MPa and elongation at break of 70.3 ± 16.2 %. Moreover, while densely grafted CNF exhibited higher modulus and strength, whereas sparsely grafted CNF displayed behavior more reminiscent of thermoplastic elastomers, indicated by lower modulus and higher elongation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Significant advancements in hydrogel-based epidermal electrodes have been made in recent years. However, inherent limitations, such as adaptability, adhesion, and conductivity, have presented challenges, thereby limiting the sensitivity, signal-to-noise ratio (SNR), and stability of the physiological-electrode interface. In this study, we propose the concept of myelin sheath-inspired hydrogel epidermal electronics by incorporating numerous interpenetrating core-sheath-structured conductive nanofibers within a physically cross-linked polyelectrolyte network. Poly(3,4-ethylenedioxythiophene)-coated sulfonated cellulose nanofibers (PEDOT:SCNFs) are synthesized through a simple solvent-catalyzed sulfonation process, followed by oxidative self-polymerization and ionic liquid (IL) shielding steps, achieving a low electrochemical impedance of 42 Ω. The physical associations within the composite hydrogel network include complexation, electrostatic forces, hydrogen bonding, π-π stacking, hydrophobic interaction, and weak entanglements. These properties confer the hydrogel with high stretchability (770%), superconformability, self-adhesion (28 kPa on pigskin), and self-healing capabilities. By simulating the saltatory propagation effect of the nodes of Ranvier in the nervous system, the biomimetic hydrogel establishes high-fidelity epidermal electronic interfaces, offering benefits such as low interfacial contact impedance, significantly increased SNR (30 dB), as well as large-scale sensor array integration. The advanced biomimetic hydrogel holds tremendous potential for applications in electronic skin (e-skin), human-machine interfaces (HMIs), and healthcare assessment devices.

Achieving highly ionic conductive hydrogels from natural wood remains challenging owing to their insufficient surface area and low number of active sites on the cell wall. This study proposes a viable strategy to design a strong and anisotropic wood-based hydrogel through cell wall nanoengineering. By manipulating the microstructure of the wood cell wall, a flexible cellulosic hydrogel is achieved through Schiff base bonding via the polyacrylamide and cellulose molecular chains. This results in excellent flexibility and mechanical properties of the wood hydrogel with tensile strengths of 22.3 and 6.1 MPa in the longitudinal and transverse directions, respectively. Moreover, confining aqueous salt electrolytes within the porous structure gives anisotropic ionic conductivities (19.5 and 6.02 S/m in the longitudinal and transverse directions, respectively). The wood-based hydrogel sensor has a favorable sensitivity and a stable working performance at a low temperature of -25 °C in monitoring human motions, thereby demonstrating great potential applications in wearable sensor devices.

Spinal cord injury (SCI) triggers interconnected malignant pathological cascades culminating in structural abnormalities and composition changes of neural tissues and impairs spinal cord tissue function. Cellulose nanofibers (CNF) have considerable potential in mimicking tissue microstructure for nerve regeneration, but the effectiveness of CNF in repairing SCI remains poorly understood. In this study, we designed a Mg-Fe layered double hydroxide (LDH)-doped cellulose nanofiber (CNF) scaffold with aligned intact microchannels and homogeneously distributed pores (CNF-LDH), loaded with retinoic acid and sonic hedgehog (CNF-LDH-RS) for neuroregeneration. The aligned microchannel structure and chemical cues in the scaffold were designed further to enhance the differentiation of neural stem cells towards neurons and promote axon growth while inhibiting differentiation to astrocytes. Transplanting the scaffolds into a completely transected SCI mice model dramatically improved behavioral and electrophysiological outcomes underpinned by robust neuronal regeneration, significant axonal growth and orderly neural circuit remodeling. RNA-seq analysis revealed the pivotal roles of the RhoA/Rock/Myosin II pathway and neuroactive ligand-receptor interaction pathway in SCI repair by CNF-LDH-RS. Particularly, Myosin II emerged as a key gene for functional recovery, and its effect on negative regulation of axon growth was suppressed by the scaffolds, resulting in a distinctly oriented growth of the axons along the microchannel structure. The results indicate that CNF-LDH scaffolds rationally combined with physical and biochemical cues create promising tissue-engineered substrates to facilitate the repair of spinal cord injury., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

Cellulose nanofibers (CNFs) have been widely used as a renewable emulsifier to stabilize two immiscible liquids due to their intrinsic amphiphilicity and excellent emulsifying ability. However, it remains challenging to fully understand the effects of carboxylate group content and surface charge density on the emulsifying ability of CNFs and the stability of Pickering emulsion. Herein, carboxymethylated CNFs were extracted from bleached kraft pulp using etherification reaction and high-pressure homogenization, allowing for easy surface charge density and size adjustment by changing sodium chloroacetate content and homogenization cycles. The optimizing CNFs possessed a high Zeta potential (-71.2 mV) and a suitable carboxylate group content (1.81 mmol/g), which enabled CNFs to irreversibly adsorb at the hydrophobic paraffin wax (PW) droplet surface and form interfacial steric barriers, providing large electrostatic repulsion between the PW droplets against coalescence. Thus, the CNF-stabilized PW emulsions could be stored for more than 6 months. Moreover, the phase change enthalpy of the freeze-dried emulsion is as high as 193.7 J/g, which provides the emulsion to reversibly store and release heat. This work provides a comprehensive insight into the interfacial stability mechanism of CNFs as stabilizers and facilitates the potential application in thermal energy storage., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

The demand for advanced biomaterials in medical treatments is rapidly expanding. To address this demand, a nanocomposite of cellulose nanofiber (CNF) with chitosan (Ch) and graphene oxide (GO) was developed for burn wound treatment. The CNF-Ch-GO nanocomposites were characterized and their biological properties were evaluated. Microscopic images showed a uniform distribution of CNF, Ch, and GO with a porous structure. ATR-FTIR and XRD analyses confirmed the chemical structures, while a thermogravimetric study confirmed the stability of CNF-Ch-GO nanocomposite under a N 2 atmosphere. The synthesized CNF-Ch-GO nanocomposite exhibited rapid absorption, absorbing 1781.7 ± 53.7 % PBS in 2 min. It demonstrated a Young's modulus of 11.90 ± 0.06 MPa in a hydrated condition, indicating its mechanical stability in water. Furthermore, it displayed excellent biocompatibility and hemocompatibility with 96.23 ± 12.21 % cell viability and 0.21 ± 0.08 % of hemolysis. Additionally, the blood clotting index of CNF-Ch-GO was comparable to that of standard dressing gauze. To enhance antimicrobial efficacy, CNF-Ch-GO was conjugated with lysozyme. This biotic and abiotic conjugation resulted in 92.17 % ± 3.02 % and 94.99 ± 2.1 % eradication of Escherichia coli and Staphylococcus aureus, respectively. The enhanced antimicrobial properties, biocompatibility, and mechanical stability of the superabsorbent CNF-Ch-GO nanocomposite indicate its significant potential for advanced burn wound healing applications., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Cellulose nanofiber (CNF) has been widely used as a flexible and lightweight polymer matrix for electromagnetic shielding and thermally conductive composite films because of its excellent mechanical strength, environmental performance, and low cost. However, the lack of flame retardancy seriously hinders its further application. Herein, renewable and biomass-sourced l-arginine (AR) was used to surface-modify ammonium polyphosphate (APP) and an environmentally friendly biobased flame retardant was synthesized by the coordination of zinc sulfate heptahydrate (ZnSO 4 ·7H 2 O), which was named AAZ. AAZ was deposited on the surface of CNF by electrostatic adsorption and Zn 2+ complexation. The biobased compatibilizer Triton X-100 was employed to assist the exfoliation of graphene nanoplatelets (GNPs) and their dispersion in the CNF matrix. Due to the formation of a dense lamellar layer resembling a shell structure, the CNF/GNPs composite films with a tensile strength of 52 MPa were obtained via vacuum-assisted filtration. Because the phosphorus-containing group produces a protective layer of P x O y compound and promotes the formation of a carbon layer by CNF and the combustion releases ammonia gas, the fire-resistant performance of the composite films was greatly improved. Compared with the pure CNF film, the composite film exhibits 33% reduction in PHRR value and 40% reduction in THR. In addition, the CNF/GNPs composite film with 20 wt % GNPs possessed high conductivity (2079.2 S/m) and electromagnetic interference (EMI) shielding effectiveness (37 dB). The ultrathin CNF/GNPs composite films have excellent potential for use as efficient flame retardant and EMI shielding materials.

In this study, we report on the development and testing of hydrophobic coatings using cellulose fibers. The developed hydrophobic coating agent secured hydrophobic performance over 120°. In addition, a pencil hardness test, rapid chloride ion penetration test, and carbonation test were conducted, and it was confirmed that concrete durability could be improved. We believe that this study will promote the research and development of hydrophobic coatings in the future.

In this work, the effect of cellulose nanofiber (CNF) on the mechanical properties of long pineapple leaf fiber (PALF)-reinforced epoxy composites was investigated. The content of PALF was fixed at 20 wt.% and the CNF content was varied at 1, 3, and 5 wt.% of the epoxy matrix. The composites were prepared by hand lay-up method. Comparison was conducted between CNF-, PALF- and CNF–PALF-reinforced composites. It was found that the introduction of these small amounts of CNF into epoxy resin caused very small effects on flexural modulus and strength of neat epoxy. However, impact strength of epoxy with 1 wt.% CNF increased to about 115% that of neat epoxy, and, as the content of CNF increased to 3 and 5 wt.%, the impact strength decreased to that of neat epoxy. Observation of the fractured surface under electron microscope revealed the change in failure mechanism from a smooth surface to a much rougher surface. For epoxy containing 20 wt.% PALF, both flexural modulus and strength increased significantly to about 300% and 240% that of neat epoxy. The composite impact strength increased to about 700% that of the neat epoxy. For hybrid systems containing both CNF and PALF, there were few changes observed in both flexural modulus and strength compared to the PALF epoxy system. However, much improvement in impact strength was obtained. By using epoxy containing 1 wt.% CNF as the matrix, the impact strength increased to about 220% that of 20 wt.% PALF epoxy or 1520% that of neat epoxy. It thus could be deduced that the spectacular improvement in impact strength was due to the synergistic effect of CNF and PALF. The failure mechanism leading to the improvement in impact strength will be discussed.

Poly (acrylic acid) (PAA) nanocomposite hydrogel was fabricated as a sensing patch for non-invasive dual detection of urea in sweat. The hydrogel was prepared by γ-irradiation crosslinking of PAA solution incorporated with graphene oxide (GO) and cellulose nanofiber (CNF). With high water-sorption capacity and transparency, the hydrogel was suitable to accommodate coloring reagents and enzymes for colorimetric sensing of urea in sweat. The colorimetric sensor exhibited vivid color change towards the increase of urea concentration in a linear range of 40–80 mM covering a cut-off value (60 mM) for chronic kidney disease (CKD) indication. Furthermore, the hydrogel could be directly applied as a substrate for direct quantitation of urea in sweat by laser desorption ionization mass spectroscopy (LDI-MS). While CNF improved the mechanical properties of the hydrogel, GO played a key role in enhancing laser desorption ionization of urea in LDI-MS and increased the hydrogel functionalities. LDI-MS verified that GO/CNF/PAA hydrogel could act as a direct matrix for promoting urea ionization and these results corresponded well with the colorimetric sensor. Hence, this hydrogel patch might be a potential material to be applied in non-invasive and dual-detection of CKD in medical diagnosis. [Display omitted] • GO/CNF/PAA hydrogel was prepared by γ-irradiation crosslinking. • The hydrogel possesses high swelling capacity and high flexibility. • The hydrogel was applied for non-invasive detection of urea in sweat. • The hydrogel was used for colorimetric screening of urea in sweat. • The hydrogel patch was used as a substrate for LDI-MS quantitation of urea. [ABSTRACT FROM AUTHOR]

Nanopapers fabricated from cellulose nanofibers (CNFs) are flexible for bending while they are rather stiff against stretching, which is a common feature shared by conventional paper-based materials in contrast with typical elastomers. Cellulose nanopapers have therefore been expected to be adopted in flexible device applications, but their lack of stretching flexibility can be a bottleneck for specific situations. The high stretching flexibility of nanopapers can effectively be realized by the implementation of Kirigami structures, but there has never been discussion on the mechanical resilience where stretching is not a single event. In this study, we experimentally revealed the mechanical resilience of nanopapers implemented with Kirigami structures for stretching flexibility by iterative tensile tests with large strains. Although the residual strains are found to increase with larger maximum strains and a larger number of stretching cycles, the high mechanical resilience was also confirmed, as expected for moderate maximum strains. Furthermore, we also showed that the round edges of cut patterns instead of bare sharp ones significantly improve the mechanical resilience for harsh stretching conditions. Thus, the design principle of relaxing the stress focusing is not only important in circumventing fractures but also in realizing mechanical resilience. [ABSTRACT FROM AUTHOR]

Cellulose nanofiber is the world's most advanced biomass material. Most importantly, it is biodegradable. In this work, nanofibers were obtained from pineapple leaves, a large solid waste in Colombia, using a combined extraction method (chemical procedures and ultrasound). The native fibers were bleached, hydrolyzed, treated with ultrasound, and characterized by scanning electron microscopy (SEM), infrared analysis (FTIR), thermogravimetric analysis (TGA), and transmission electron microscopy (TEM). As a comparison, a commercial microcrystalline cellulose sample was analyzed, which demonstrated the efficiency of cellulose extraction. The nanofibers had a diameter and a length of 18 nm and 237 nm, respectively, with a maximum degradation temperature of 306 °C. The analysis showed the efficiency of acid treatment combined with ultrasound to obtain nanofibers and confirmed that pineapple residues can be valorized by this method. These results indicate that lignocellulosic matrices from pineapple leaves have potential application for obtaining polymeric-type composite materials. Due to their morphology and characteristic physical properties, the cellulose nanofibers obtained in this work could be a promising material for use in a wealth of fields and applications such as filter material, high gas barrier packaging material, electronic devices, foods, medicine, construction, cosmetics, pharmacy, and health care, among others. [ABSTRACT FROM AUTHOR]

Nanofibrillated cellulose (NFC) is a type of nanocellulose with multiple functionalities. Typically, NFC is produced via mechanical high-pressure homogenization process. However, this process is energy intensive and the fibrous nature of NFC often causes instrument blockage. The present study aims to utilize endoglucanase enzyme as an environmentally-friendly approach to pretreat fiber structure prior to undergoing mechanical defibrillation for the production of NFC from corn cob. Alkaline-and bleached-pretreated corn cob was reacted with endoglucanase Fibercare R from 0 to 2.5% before passing through the high-pressure homogenizer. It was found that the incorporation of 0.02% endoglucanase was sufficient to soften the corn cob cellulose and further prevented the blockage of the homogenizer. Subsequently, the 0.02% endoglucanase-treated corn cob was passed through different homogenization cycles (0–10 cycles) for NFC production. The water retention, Zeta potential, and shear viscosity of the NFC increased with higher homogenization cycle during the NFC production and the resulting NFC had a gel-like consistency. Next, emulsifying-stabilizing properties of the NFC produced from cycle 0 to cycle 10 as well as their amount from 0 to 1% were also assessed. The increase in homogenization cycle and amount of NFC promoted emulsion stability can be observed from the low creaming index, which is mainly attributed to the high shear viscosity and G'G" crossover of the emulsion. Overall, the NFC derived from corn cob via enzymatic coupled with high-pressure homogenization process has the potential to be used as gel-like stabilizer in oil-in-water food emulsion system. [ABSTRACT FROM AUTHOR]

Development of new adsorbent based on anionic silica precursor, cellulose nanofiber (CNF), and graphene oxide (GO) has prepared via ionic reaction followed by a sol–gel process. Different instruments were used for the characterization of the nanocomposite: Fourier transform infrared spectrometer (FTIR), X‐ray diffraction (XRD), scanning electronic microscope (SEM), Thermal gravimetric analysis (TGA), and transmission electron microscope (TEM). Methylene blue (MB) adsorption on CNF/GO and CNF/GO/silica nanocomposites achieved during 60 min. A pseudo‐second‐order kinetic model was fitted to the adsorption process, with a maximum adsorption capacity of 588.23 and 625 mg/g in a slightly alkaline solution, respectively. It was found that the adsorption capacity of CNF/GO and CNF/GO/silica could regenerate the MB up to four cycles with slight decrease from 98 to 93%. This study showed that CNF/GO and CNF/GO/silica nanocomposites are effective adsorbents for organic pollutants in wastewater. [ABSTRACT FROM AUTHOR]

In this work, cellulose nanofiber was prepared from water hyacinth (WH) using a simple domestic blender and employed as reinforcement in recycled paper. There are various sources to prepare cellulose nanofiber. However, water hyacinth was used as a source to synthesize cellulose in this study to decrease its devastating effect on the water body. Pure cellulose was isolated from water hyacinth with chemical treatments including dilute alkali swelling and bleaching. The chemical composition of water hyacinth was gravimetrically determined and the result demonstrated that cellulose is the largest constituent of the plant (55%), followed by hemicelluloses (19%) and lignin (14%). The remaining 12% was related to other extracts like fat, oil, pectin, etc. As the FTIR data revealed, the functional groups corresponding to lignin and hemicelluloses were absent in the FTIR spectra of extracted cellulose. To increase its functionality, the prepared cellulose was disintegrated into nanofibers using a simple mechanical treatment. To learn more about cellulose fibrillation, UV–Vis spectroscopy was used to analyze the light transmittance of 1 wt% water dispersed, mechanically treated cellulose. The dispersion showed high light transparency, particularly at a higher wavelength. As a result of the cellulose dispersion's reasonable light transmittance value, it can be deduced that the aggregated cellulose chains were efficiently transformed into nanofibers. The inclusion of cellulose nanofibers as reinforcement significantly improved recycled paper's moisture resistance, thermal stability, and mechanical strength. [ABSTRACT FROM AUTHOR]

Cellulose nanofibrils (CNFs) have attracted a great deal of research interest in recent years attributable to the low cost and abundance of lignocellulosic biomass from which they can be extracted. These materials have potential applications in a wide array of areas because of their unique properties such as ultra-high aspect ratios and specific strengths. However, the high energy required to extract CNFs from biomass through fibrillation often makes them prohibitively expensive or negates their inherent sustainability. As such, a variety of biomass treatments prior to fibrillation have been investigated by researchers to reduce the energy requirements of CNF extraction, improve the efficacy of biomass fibrillation and subsequent processes, and/or impart functionality in resulting nanofibrils. In this review, both widely used and emerging mechanical, chemical, and enzymatic pretreatments used prior to fibrillation of lignocellulosic biomass for CNF extraction are reviewed. Attention is given to the effect of these various pretreatments on the properties of the resulting CNFs. Finally, the energy consumption in fibrillation processes with and without the use of pretreatments is compared, and future perspectives on challenges and opportunities in lignocellulosic feedstock pretreatments are discussed. [ABSTRACT FROM AUTHOR]

Polymer nanocomposites with excellent electromagnetic interference (EMI) shielding and thermal conductivity (TC) are urgently needed to solve the increasingly serious electromagnetic pollution and heat accumulation in devices. Herein, a distinct strategy was proposed to improve the dispersity of graphene nanoplatelets (GNPs) and integrate cellulose nanofiber (CNF), graphene nanoplatelets (GNPs), and MXene into a layered structure. The presence of MXene can improve the dispersity of GNPs, and the presence of GNPs can protect MXene from oxidation. By combining the excellent electrical conductivity of MXene and the high thermal conductivity of GNPs, the CNF/GNPs/MXene composite films exhibit excellent EMI shielding performance and high in-plane thermal conductivity. The electromagnetic shielding property of the CNF/GNPs/MXene composite films reaches 33.74 dB and the in-plane TC is 8.55 W/(m·K) when the total filler content is 50 wt % while the thickness of the composite film is only 38.5 μm. In addition, the mechanical properties of the composite membrane can meet general requirements. Therefore, these ultrathin CNF/GNPs/MXene composite films show great application potential as effective EMI shielding and thermal management materials. [ABSTRACT FROM AUTHOR]

In this study, a system was designed that can encapsulate and deliver gallic acid (GA), which was composed of polysaccharide polymers based on sodium alginate (SA), carboxymethyl chitosan (CCT), and cellulose nanofibers (CN) and was assisted by porous starch. The compositions were characterized by rheology and zeta potentials, and the results showed that the materials used in this study could effectively guarantee the stability of the system. The morphology and chemical structure of the beads were characterized by SEM and FT-IR, the results indicated that the addition of CCT could effectively reduce the cracks and pores on the surface of the beads, which was beneficial to the encapsulation and delivery of GA. Moreover, the results of the swelling rate, release tests, and antioxidant tests also proved the effectiveness of the system. The pH response effect of SA/CN/CCT (SCC) beads and the protection of GA were superior, and the release rate of GA in simulated gastric fluid (SGF) was only 6.95%, while SA and SA/CN (SCN) beads reached 57.94% and 78.49%, respectively. In conclusion, the interpenetrating network polymers constructed by SA, CCT, and CN, which, combined with porous starch as a coating layer, can achieve the embedding and the delivery of GA. [ABSTRACT FROM AUTHOR]

The rheological and thermal properties of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) and chemically modified cellulose nanofiber nanocomposites (PHBH/CNF) were investigated. The processability of the PHBH/CNF composite was also tested using an injection molding machine. Surface modification of CNF was conducted with alkenyl succinic anhydride (ASA) to control the viscosity and the crystallization rate of PHBH. The fast-scanning calorimeter (FSC) analysis showed that the crystallization rate of PHBH/CNF became four times faster than that of pure PHBH. The rheological measurement indicated that the dispersed ASA-modified CNF formed a network structure in PHBH and increased complex viscosity and storage modulus by about two to three orders of magnitude. Although PHBH alone is vulnerable to heat treatment, PHBH/CNF composites can improve rheological and thermal properties, reduce crystal size and reinforce the mechanical property. As a result, these effects increased the processability of PHBH by the injection molding process. [ABSTRACT FROM AUTHOR]

Silver nanoparticles (AgNPs) on the surface of cellulose nanofibers (CNF) were immobilized using a high-pressure wet-type jet mill to increase their stability while maintaining their catalytic activity. As a raw starting material, an aqueous silver nitrate solution was mixed with a CNF suspension. The mixture was then processed five times using the high-pressure wet-type jet mill at a discharge pressure of 100 MPa. AgNPs with an average particle size of 3.8 « 0.8nm were immobilized and well-dispersed on the surface of CNF, as observed by transmission electron microscopy. The catalytic activities of the AgNPs coated with PVP (AgPVP) and the prepared AgNPs-supported on CNF composite (AgCNF) were evaluated. As a result, the catalytic activity of AgCNF was discovered to be 2.32 times greater than that of AgPVP. The catalytic activity was measured in terms of the number of runs because AgCNF can be easily recovered by centrifugation or filtration. Even the catalytic activity of AgCNF after five runs was maintained at 62%, but the catalytic activity gradually decreased as the number of runs increased. [ABSTRACT FROM AUTHOR]

The application of coatings is a strategy for maintaining the freshness of highly perishable fruits. This research aimed to evaluate the quality indices of strawberries (Amaou) coated with new coatings based on the sodium carboxymethyl cellulose (CMC) and cellulose nanofibres (CNF) with incorporated mandarin peel extract (ME) or 1-methylcyclopropene (1-MCP) during storage at 20 days at 5 °C and 85% relative humidity (RH). Dissolving the coating solution containing ME in 1-MCP maintained its colour for up to 50 days. Coatings enhanced with ME and/or 1-MCP maintained fresh strawberries more effectively than the control, reducing weight loss and maintaining firmness, total soluble solids (TSS), citric acid, colour, and total phenolic content. The CCM2–2 coating solution showed superior effects on the weight loss and relative percentages of strawberry metabolites compared to the other coatings, as confirmed by the different components. [Display omitted] • Diluting of 1-MCP in coatings helped to maintain the coating colour up to 50 days • Coatings containing 1-MCP showed significant absorption values in spectra peaks • Mandarin peel extract indicated significant changes in the roughness values of films • Coatings had a marked effect on weight loss, firmness, and metabolic profiles [ABSTRACT FROM AUTHOR]

The development and application of flexible electrodes with extended cycle life have long been a focal point in the field of energy research. In this study, positively charged polyethylene imine (PEI) and conductive polymer poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) with negative charge were alternately deposited onto a cellulose nanofiber (CNF) porous material utilizing pressure gradient-assisted layer-by-layer (LbL) self-assembly technology. The flexible substrate, characterized by a three-dimensional porous structure reinforced with stiff CNF, not only facilitated high charge storage but also enhanced the electrode's cycling life by reducing the volume changes of PEDOT:PSS. Furthermore, the exceptional wettability of PEI by the electrolyte could promote efficient charge transport within the electrode. The electrode with 10 PEI/PEDOT:PSS bilayer exhibits a capacitance of 63.71 F g−1 at the scan rate of 5 mV s−1 and a remarkable capacitance retention of 128 % after 3000 charge-discharge cycles. The investigation into the nanoscale layers of the LbL multilayer structure indicated that the exceptional cyclic performance was primarily attributed to the spatial constraints imposed by the rigid porous substrate layered structure on the deformation of PEDOT:PSS. This work is expected to make a significant contribution to the development of electrodes with high charge storage capacity and ultra-long cycling life. [Display omitted] [ABSTRACT FROM AUTHOR]

Flexible thermal insulation materials have garnered significant attention owing to the proliferation of flexible electronic devices and their diverse application environments. Plant-derived thermoplastic polyester elastomer (TPEE) foams emerge as promising candidates in the field of flexible thermal insulation. However, inevitable shrinkage behavior of TPEE foams would result in reduced porosity and inferior thermal insulation performance. Hence, a pioneering approach is proposed wherein cellulose nanofibers (CNF) are integrated into TPEE matrixes, complemented by microcellular foaming, aimed at mitigating shrinkage process and enhancing thermal insulation properties. In this work, the relaxation behavior of nanocomposite, corresponding to shrinkage process, has been elucidated through dynamic mechanical analysis. It's found that entanglement of CNF could heighten the internal friction with TPEE molecular chains, coupled with establishment of hydrogen bonds, thereby curbing relaxation phenomena and facilitating the attainment of foams with enhanced and stable porosity. The shrinkage ratio of TPEE/CNF composite foam could be reduced by 20 % without compromising the final porosity. The thermal conductivity would decrease to 37.9 mW/m·K for the TPEE/CNF composite foam with the higher porosity of 0.947. Moreover, the utilization of CNF presents a novel avenue for fabricating TPEE/CNF nanocomposite foams endowed with flexibility, lightweightness, increased porosity, and reduced thermal conductivity. [Display omitted] [ABSTRACT FROM AUTHOR]

Stem cell culture often requires various animal-derived components such as serum and collagen. This limits its practical use. Therefore, xeno-free (xenogeneic component-free) culture systems are receiving increased attention. Herein, we propose xeno-free, plant-derived cellulose nanofibers (CNFs) with different surface chemistry: 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-oxidized CNFs (TOCNFs) with carboxy groups and surface-sulfated CNFs (S-CNFs) for the proliferation of human mesenchymal stem cells (hMSCs) under various serum conditions. We cultured bone marrow-derived hMSCs on CNF scaffolds with various fiber lengths and functional group contents. Original CNFs were bioinert materials that did not contribute to cell adhesion. In contrast, the surface-modified CNFs facilitated the proliferation of immortalized hMSCs under normal and low-serum conditions. The TOCNFs (COONa: 1.47 mmol g−1; length: 0.53 μm), the S-CNFs (OSO 3 Na: 0.64 mmol g−1; 0.61 μm), and a combination of the two (1:1 by weight) enabled immortalized hMSCs to maintain their multipotency, even under serum-free conditions. Primary cultured hMSCs proliferated well on the TOCNF/S-CNF scaffolds in a completely serum-free medium, comparable to animal-derived type I collagen, although few hMSCs adhered to the standard polystyrene substrate. Our strategy of using surface-modified CNFs will inform the development of xeno-free culture systems to avoid the use of animal-derived materials for both cell culture media and scaffolds. [Display omitted] [ABSTRACT FROM AUTHOR]

Generally, glass fiber-reinforced polymer composites are made in the form of laminated composites. Due to the weak adhesion between the fiber and the polymer matrix, failure in the form of delamination often occurs. To overcome delamination, the incorporation of very low content of nanomaterials has been considered. The effect of cellulose nanofibers (CNFs) addition on the mechanical, morphological, and thermal properties of the epoxy/glass fiber/CNFs hybrid composites was evaluated. The hybrid composites containing 1 and 2 wt% CNFs were prepared by hand lay-up followed by vacuum bagging and compression. The mechanical characteristics of the composites were investigated through tensile, flexural, short beam shear, and impact tests, while thermal stability was evaluated by thermogravimetric analysis (TGA). The results revealed that with the presence of 1 wt% CNF, the tensile strength and modulus of the epoxy/glass fiber composites were enhanced by 9 and 10%, respectively whereas the flexural strength and modulus were increased by 16 and 6%, respectively. SEM observations showed the presence of a strong CNF interaction with glass fiber and a thin layer of epoxy interphase around the glass fibers. Moreover, the introduction of 1 wt% CNF to the epoxy/glass fiber composite improved the interlaminar shear strength by 11%, while the thermal stability did not change.

Beef is considered the main source of dietary protein despite being perishable. In this regard, utilization of biodegradable films containing plant essential oils, as antimicrobial compounds, is one of the concepts to prolong the beef shelf life. Accordingly, this study aimed to investigate the effect of the biodegradable film based on orange waste powder (OWP) containing nettle essential oil (NEO) and cellulose nanofiber (CNF) to increase the shelf life of the refrigerated beef samples stored for 12 days. As well, beef samples were divided into three groups of uncovered (control), wrapped with the OWP-based film without essential oil and nanofiber and wrapped with OWP-base film containing 3% NEO and 6% CNF and the microbial (aerobic mesophilic count, psychrophilic count, and coliform count) and chemical (pH, thiobarbituric acid and volatile nitrogen bases) properties were evaluated at regular intervals (0, 4, 8 and 12days). According to the results, the beef sample wrapped with OWP-base film containing 3% NEO and 6% CNF showed the lowest growth rate of the mentioned bacteria after 12 days of storage; Moreover, the samples covered by the film containing NEO and CNF had lower levels of pH, thiobarbituric acid and volatile nitrogen bases values compared to the other two samples at 12th day of storage. The results of this study indicate that wrapping beef samples with an OWP-based nanobiocomposite film containing 3% NEO and 6% CNF could remarkably prolong its shelf life in refrigerated conditions. TRANSLATE with x English Arabic Hebrew Polish Bulgarian Hindi Portuguese Catalan Hmong Daw Romanian Chinese Simplified Hungarian Russian Chinese Traditional Indonesian Slovak Czech Italian Slovenian Danish Japanese Spanish Dutch Klingon Swedish English Korean Thai Estonian Latvian Turkish Finnish Lithuanian Ukrainian French Malay Urdu German Maltese Vietnamese Greek Norwegian Welsh Haitian Creole Persian // TRANSLATE with COPY THE URL BELOW Back EMBED THE SNIPPET BELOW IN YOUR SITE Enable collaborative features and customize widget: Bing Webmaster Portal Back // TRANSLATE with x English Arabic Hebrew Polish Bulgarian Hindi Portuguese Catalan Hmong Daw Romanian Chinese Simplified Hungarian Russian Chinese Traditional Indonesian Slovak Czech Italian Slovenian Danish Japanese Spanish Dutch Klingon Swedish English Korean Thai Estonian Latvian Turkish Finnish Lithuanian Ukrainian French Malay Urdu German Maltese Vietnamese Greek Norwegian Welsh Haitian Creole Persian // TRANSLATE with COPY THE URL BELOW Back EMBED THE SNIPPET BELOW IN YOUR SITE Enable collaborative features and customize widget: Bing Webmaster Portal Back //TRANSLATE with xEnglishArabicHebrewPolishBulgarianHindiPortugueseCatalanHmong DawRomanianChinese SimplifiedHungarianRussianChinese TraditionalIndonesianSlovakCzechItalianSlovenianDanishJapaneseSpanishDutchKlingonSwedishEnglishKoreanThaiEstonianLatvianTurkishFinnishLithuanianUkrainianFrenchMalayUrduGermanMalteseVietnameseGreekNorwegianWelshHaitian CreolePersian // TRANSLATE with COPY THE URL BELOW BackEMBED THE SNIPPET BELOW IN YOUR SITE Enable collaborative features and customize widget: Bing Webmaster PortalBack//

In order to achieve an aerogel with both rigid pore structures and desired flexibility, stiff carboxyl-functionalized cellulose nanofiber (CNFs) were introduced into a flexible polyvinyl alcohol-polyethyleneimine (PVA-PEI) crosslinking network, with 4-formylphenylboronic acid (4FPBA) bridging within the PVA-PEI network to enable dynamic boroxine and imine bond formation. The strong covalent bonds and hydrogen connections between CNF and the crosslinking network enhanced the wet stability of the aerogel while also contributed to its thermal stability. Importantly, the harmonious coordination between the stiff CNF and the flexible polymer chains not only facilitated aerogel flexibility but also enhanced its increased specific surface area by improving pore structure. Moreover, the inclusion of CNF enhanced the adsorption capacity of the aerogel, rendering it effective for removing heavy metal ions. The specific surface area and adsorption capacity for copper ions of the aerogel increased significantly with a 3 wt% addition CNF suspension, reaching 19.74 m2 g−1 and 60.28 mg g−1, respectively. These values represent a remarkable increase of 590.21 % and 213.96 %, respectively, compared to the blank aerogel. The CNF-enhanced aerogel in this study, characterized by its well-defined pore structures, and desired flexibility, demonstrates versatile applicability across multiple domains, including environmental protection, thermal insulation, electrode fabrication, and beyond. [ABSTRACT FROM AUTHOR]

[Display omitted] • Biomimetic microfiber with a nacre-like microstructure were made by wet-spinning. • The Co/C/CNF/Ti 3 C 2 T x fiber achieved RL min value of −62.3 dB and EAB of 5.86 GHz. • Heterogeneous interface of nacre-like structure brings superior microwave absorption. Although considerable efforts have been made in the fabrication of MXene-based composites for microwave absorption (MA), there is a great challenge to assemble MXene into regularly arranged microfibers prepared by wet-spinning technique for application in the field of MA due to insufficient interlayer interactions between Ti 3 C 2 T x flakes. Heterogeneous interface design by optimizing material components to construct ingenious microstructure is crucial for efficient microwave absorbers. Herein, artificial nacre-like supramolecular microfibers of Co/C modified cellulose nanofiber/Ti 3 C 2 T x MXene (Co/C/CNF/Ti 3 C 2 T x) with plenty of heterogeneous interfaces were prepared by a simple wet-spinning technology through a self-assembly process induced by hydrogen bonding interactions between CNF and Ti 3 C 2 T x. The artificial nacre-like microfibers with layered structure possess abundant heterogeneous interfaces, which facilitate multiple reflections/scattering of electromagnetic waves (EMW) between these interfaces, and at the same time promote interfacial and dipole polarization. The introduction of magnetic Co/C nanoparticles not only offer additional magnetic loss ability and improved impedance matching, but also enhance conductivity loss and polarization loss. Benefiting from these advantages, Co/C/CNF/Ti 3 C 2 T x (1:1:1) fiber exhibits superior MA performance with a minimum reflection loss (RL min) of up to −62.32 dB (>99.9999 % energy absorption) and a broad effective absorption bandwidth (EAB) of 5.86 GHz. The work provides a promising method for the preparation of biomimetic artificial nacre-like MXene-based microfibers with efficient MA performance, which is expected to be applied in the field of flexible wearable electromagnetic protection. [ABSTRACT FROM AUTHOR]

Cellulose nanofiber was an ideal candidate for humidity actuators based on its wide availability, biocompatibility and excellent hydrophilicity. However, conventional cellulose nanofiber-based actuators faced challenges like poor water resistance, flexibility, and sensitivity. Herein, water-resistant, flexible, and highly sensitive cross-linked cellulose nanofibers (CCNF) single-layer humidity actuators with remarkable reversible humidity responsiveness were prepared by combining the green click chemistry modification and intercalation modulated plasticization (IMP). The incorporation of phenyl ring and the crosslinked network structure in CCNF films contributed to its improved water resistance and mechanical properties (with a stress increased from 85.9 ± 3.1 MPa to 141.2 ± 21.5 MPa). SEM analysis confirmed enhanced interlaminar sliding properties facilitated by IMP. This resulted in increased flexibility and toughness of CCNF films, with a strain of 11.5 % and toughness of 9.9 MJ/m3. These improvements efficiently enhanced humidity sensitivity for cellulose nanofiber, with a 4.8-fold increase in bending curvature and a response time of only 3.4 ± 0.1 s. Finally, the good humidity sensitivity of modified CNF can be easily imparted to carbon nanotubes (CNTs) via simple self-assembly method, thus leading to a high-performance humidity-responsive actuator. The click chemistry modification and IMP offer a new avenue to fabricate tough, reversible and highly sensitive humidity actuator based on cellulose nanofiber. [Display omitted] [ABSTRACT FROM AUTHOR]

Recently, attention has been paid to cellulose nanofibers, such as 2,2,6,6-tetramethylpiperidine-1-oxyl-oxidized cellulose nanofibers (TOCN), as new bio-based materials. In addition, hydrophobized surface on TOCNs can be expected to provide new applications. Based on our previous finding that partially 2-deoxygenated (P2D)-amylose, which was synthesized by GP-catalyzed enzymatic copolymerization of D-glucal with α- d -glucose 1-phosphate (Glc-1-P) as comonomers, was hydrophobic, in this study, hydrophobization of surfaces on TOCNs was investigated by the GP-catalyzed enzymatic grafting of P2D-amylose chains on TOCNs. After maltooligosaccharide primers were modified on TOCNs, the GP-catalyzed enzymatic copolymerization of D-glucal with Glc-1-P was performed for grafting of P2D-amylose chains. 1H NMR spectroscopic analysis confirmed the production of P2D-amylose-grafted TOCNs with different 2-deoxyglucose/Glc unit ratios. The powder X-ray diffraction profiles of the products indicated that the entire crystalline structures were strongly affected by the unit ratios and chain lengths of the grafted polysaccharides. The SEM images observed differences in nanofiber diameter in the reaction solutions and surface morphology after film formation, due to grafting of P2D-amylose chains from TOCNs. The water contact angle measurement of a cast film prepared from the product indicated its hydrophobicity. [Display omitted] [ABSTRACT FROM AUTHOR]

The preparation of cellulose nanofiber (CNF) using traditional methods is currently facing challenges due to concerns regarding environmental pollution and safety. Herein, a novel CNF was obtained from bamboo shoot shell (BSS) by low-concentration acid and dynamic high-pressure microfluidization (DHPM) treatment. The resulting CNF was then characterized, followed by in vitro and in vivo safety assessments. Compared to insoluble dietary fiber (IDF), the diameters of HIDF (IDF after low-concentration acid hydrolysis) and CNF were significantly decreased to 167.13 nm and 70.97 nm, respectively. Meanwhile, HIDF and CNF showed a higher crystallinity index (71.32 % and 74.35 %). Structural analysis results indicated the successful removal of lignin and hemicellulose of HIDF and CNF, with CNF demonstrating improved thermostability. In vitro , a high dose of CNF (1500 μg/mL) did not show any signs of cytotoxicity on Caco-2 cells. In vivo , no death was observed in the experimental mice, and there was no significant difference between CNF (1000 mg/kg·bw) and control group in hematological index and histopathological analysis. Overall, this study presents an environmentally friendly method for preparing CNF from BSS while providing evidence regarding its safety through in vitro and in vivo assessments, laying the foundation for its potential application in food. [Display omitted] [ABSTRACT FROM AUTHOR]

Cellulose nanofiber (CNFs) obtained through TEMPO oxidation was structurally characterized using FT-IR (Fourier Transformed Infrared) and SEM (Scanning Electron Microscopy) spectroscopy. The molecular aggregation and spectroscopic properties of Rhodamine B (Rh-B) in CNFs suspension were investigated using molecular absorption and steady-state fluorescence spectroscopy techniques. The interaction between CNFs particles in the aqueous suspension and the cationic dye compound was examined in comparison to its behavior in deionized water. This interaction led to significant changes in the spectral features of Rh-B, resulting in an increase in the presence of H-dimer and H-aggregate in CNFs suspension. The H-type aggregates of Rh-B in CNFs suspensions were defined by the observation of a blue-shifted absorption band compared to that of the monomer. Even at diluted dye concentrations, the formation of Rh-B’s H-aggregate was observed in CNFs suspension. The pronounced aggregation in suspensions originated from the strong interaction between negatively charged carboxylate ions and the dye. The aggregation behavior was discussed with deconvoluted absorption spectra. Fluorescence spectroscopy studies revealed a significant reduction in the fluorescence intensity of the dye in CNFs suspension due to H-aggregates. Furthermore, the presence of H-aggregates in the suspensions caused a decrease in the quantum yield of Rh-B compared to that in deionized water. [ABSTRACT FROM AUTHOR]

The improvement of the properties of starch, carrageenan, and polyvinyl alcohol (SCPVA) bio-thermoplastics film is necessary be used as packaging materials that comply with SNI 7818:2014 and international standards. The aim of this research is to optimize the concentration of cellulose nanofiber and castor oil in the synthesis of SCPVA bio-thermoplastic film; so that, the best characteristics are obtained and SNI 7818:2014 and international standards are met. Optimization was carried out using the Response Surface Methodology (RSM) application with the independent variable (input control variable) concentration of cellulose nanofiber and castor oil with the dependent variable (response variable) tensile strength, elongation at break, and Young Modulus. SCPVA bio-thermoplastic film with an optimal concentration of cellulose nanofiber and castor oil was observed for swelling, WVTR, surface profile, functional group content, thermal stability, and crystallinity by reviewing X-ray diffraction intensity. The research results showed that the optimum concentrations of cellulose nanofiber and castor oil in the synthesis of SCPVA bio-thermoplastic film are 6.05% and 0.96%, respectively. The tensile strength, elongation at break and Young's modulus values of the resulting optimum treatment are 37.21 MPa, 4.347% and 1041.86 MPa, respectively. Hence, with optimization, the SCPVA bio-thermoplastic film has the highest tensile strength and Young's modulus values but the lowest elongation at break values. The physical and mechanical characteristics of SCPVA bio-thermoplastic film have met SNI 7818:2014 and most of ASTM 5336, therefore, it can be used as packaging. [ABSTRACT FROM AUTHOR]

Solar-driven interfacial evaporation has received substantial attention in a variety of applications, including water purification, seawater desalination, and energy production. However, creating a straightforward, adaptable, and scalable method for correctly integrating hybrid solar-thermal systems continues to be a challenging task. Herein, we propose an economical, scalable, and environmentally friendly approach for achieving synergistic coupling of interfacial solar energy conversion for evaporation and low-grade thermal energy conversion to electricity by incorporating zinc oxide (ZnO) nanoparticle-modified MXene (ZNM- MXene) into cellulose nanofiber (CNF) films. The vacuum filtering approach produces CNF@ZNM-MXene composite films with enhanced photothermal conversion efficiency, capillary hydrophilicity, and thermal localization. Because of its rapid water transport capability, excellent sunlight absorption, and efficient solar-thermal conversion under 1 kW m−2 irradiance, the CNF@ZNM-MXene solar evaporator's evaporation rate reaches 1.27 kg m−2 h−1, and the solar-vapor conversion efficiency is as high as 82.15%, outperforming most previously reported solar evaporators. Moreover, when compared to a standalone thermoelectric (TE) module, the output power of the solar thermal conversion system coupled with a CNF@ZNM-MXene composite films and a TE module is boosted by 15.32 times. This work offers a practical and effective method for simultaneously capturing solar energy and desalinating saltwater. [Display omitted] [ABSTRACT FROM AUTHOR]

Cryogels that are constructed with cellulose nanofibrils (CNF) are important as green materials for a wide range of applications. However, their utilization is limited by inherent hydrophilicity and insufficient mechanical properties. Herein, a processable CNF/nanochitin (NCh)-stabilized Pickering emulsion that contains polylactide (PLA) in the oil phase is developed to directly produce ternary composite cryogels via freeze-drying. The complexation of CNF with NCh promotes CNF adsorption at the surface of PLA droplets, resulting in formation of uniform Pickering PLA droplets. The CNF/NCh complex-stabilized PLA droplets are easy to be translated to the internal structure of the cryogels, exhibiting lightweight nature and possessing highly porous structure. The interconnected network and lamellar structure formed by the CNF/NCh complexes, associating with inclusion of PLA particles, improve the cryogel structure integrity upon post-processing and endow hydrophilic cryogel with water resistance. This study offers a straightforward and eco-friendly Pickering emulsion template on fabrication of the CNF-based composite cryogel with controllable microstructure and mechanical performance, broadening construction of nanocellulose-based composites. [Display omitted] [ABSTRACT FROM AUTHOR]

This paper reports an environment-friendly biobased foam made with cellulose nanofiber (CNF) and a biobased hyperbranched crosslinker, glycerol succinic anhydride (GSA). As a biobased hyperbranched crosslinker, carboxyl-terminated GSA is synthesized through a straightforward esterification process involving glycerol and succinic anhydride. The GSA-crosslinked CNF (GSA/CNF) foam is prepared using a facile, sustainable, cost-effective, and efficient solvent-exchange method. The resulting foam exhibits notable characteristics, including improved dimensional stability, remarkably low density (13.41 mg/cm3) with high porosity (>99 %), and exceptional compressive strength (494 kPa) and modulus (452 kPa). Further, the foam offers outstanding sound absorption capabilities with a coefficient of 0.986 at 2 kHz and remarkably low thermal conductivity (30.18 mW/mK), significantly lower than commonly used and reported porous materials, indicating its potential as an efficient, environmentally friendly sound absorption and thermal insulation material. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • A photothermal responsive cellulose carbon capture material was engineered. • Functional groups could be regulated due to a high reagents conversion rate (99%). • The temperature sensitivity of material endowed it low regeneration temperature. • The material possessed a solar-driven regeneration temperature as low as 55 °C. The utilization of the solar-driven CO 2 desorption of carbon capture materials opens a promising avenue to reduce energy consumption in the carbon capture process. A crucial aspect is the careful coordination of materials' adsorption capacity and regeneration temperature. In this study, a photothermal responsive carbon capture material was developed by incorporating a photothermal responsive cellulose nanofiber matrix skeleton with a temperature-sensitive Pluronic® F-127 and polyethyleneimine. These components formed a staggered network through crosslinking with epichlorohydrin. The devised preparation strategy demonstrated a remarkable conversion rate of 99% for the reaction reagents. The resulting carbon capture material exhibited a high amino density of 14.18 mmol/g and a substantial adsorption capacity of 6.92 mmol/g. Notably, the shrinkage of Pluronic® F-127 molecular chains at elevated temperatures led to an increased surface electrostatic potential and the passivation of amino groups. This transformation endowed the material with a solar-driven regeneration temperature as low as 55 °C, representing an efficient approach to reduce energy consumption during the regeneration process of carbon capture materials. [ABSTRACT FROM AUTHOR]

Sustainable strategies to improve the water resistance of cellulose paper are actively sought. In this work, polymeric microspheres (PMs), prepared through emulsion polymerization of cellulose nanofibers stabilized rubber seed oil-derived monomer, were investigated as coatings on corrugated medium paper (CMP). After infiltrating porous paper with PMs, the water-resistant corrugated papers (WRCP n) with enhanced mechanical properties were obtained. When 30 wt% PMs were introduced, WRCP 30 turned out to be highly compacted with an increased water contact angle of 106.3° and a low water vapor transmission rate of 81 g/(m2 d) at 23 °C. Meanwhile, the tensile strength of WRCP 30 increased to 22.2 MPa, a 4-fold increase from CMP. When tested in a well-hydrated state, 71% of its mechanical strength in the dry state was maintained. Even with a low content of 10 wt% PMs, WRCP 10 also exhibited stable tensile strength and water wettability during the cyclic soaking-drying process. Thus, the plant oil based sustainable emulsion polymers provide a convenient route for enhancing the overall performance of cellulose paper. • Polymeric composite microspheres (PMs) were prepared via emulsion polymerization from CNFs stabilized ERSMA emulsion. • The PMs were utilized as coatings on corrugated medium paper to fabricate high-performance packing materials. • The prepared PMs coated CMPs exhibit enhanced mechanical properties and long-term water resistance. [ABSTRACT FROM AUTHOR]

This study aimed to develop a multifunctional active composite film to extend the shelf life of minced pork. The composite film was prepared by incorporating zinc-doped grapefruit peel-derived carbon quantum dots (Zn-GFP-CD) into a cellulose nanofiber (CNF) matrix. The resulting film significantly improved UV-blocking properties from 39.0 % to 85.7 % while maintaining the film transparency. Additionally, the CNF/Zn-GFP-CD5% composite film exhibits strong antioxidant activity with ABTS and DPPH radical scavenging activities of 99.8 % and 77.4 %, respectively. The composite film also showed excellent antibacterial activity against both Gram-negative and Gram-positive bacteria. When used in minced pork packaging, the composite films effectively inhibit bacterial growth, maintaining bacterial levels below 7 Log CFU/g after 15 days and sustaining a red color over a 21-day storage period. Additionally, a significant reduction in the lipid oxidation of the minced pork was observed. These CNF/Zn-GFP-CD composite films have a great potential for active food packaging applications to extend shelf life and maintain the visual quality of packaged meat. • Zinc-doped grapefruit peel-derived carbon dots (Zn-GFP-CDs) were successfully synthesized. • CNF/Zn-GFP-CDs composite films showed excellent antimicrobial activities against several bacteria. • CNF/Zn-GFP-CDs composite films improved UV barrier properties with maintaining transparency. • CNF/Zn-GFP-CDs composite film improved the quality of minced pork. [ABSTRACT FROM AUTHOR]