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Copyright of Science & Technology of Food Industry is the property of Science & Technology of Food Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Nanocellulose has emerged as a widely utilized building block in nanostructured materials due to its availability, sustainability, large surface area, and high stiffness and aspect ratio. The wet or dry elastoplastic properties of these materials are determined by the fibrils' stiffness, chemical properties, hemicellulose content, and the number of fibril contacts. However, the specific contributions and relative importance of each factor remain unclear. Therefore, this work was devoted to systematically comparing the material properties of gels, aerogels, and wet and dry sheets prepared from CNFs with different aspect ratios, chemical functionality, and hemicellulose content. The fibrils were prepared by chemical and mechanical processing of different pulps. By preserving the native structure as much as possible, higher aspect ratio fibrils can be obtained, which allows for the development of more mechanically robust materials. The results demonstrate that higher aspect ratios lead to more interconnected networks at a lower solids concentration, resulting in a more evenly distributed stress and longer-range stress transfer, yielding stiffer and more ductile materials. The most important finding was that the aspect ratio influences the network formation, resulting in different network topologies. The results were also compared to earlier published data and integrated into a theoretical beam-bending model for a complete elastoplastic description of the network properties, including the influence of fibril aspect ratio and chemical functionality. This information improves our understanding and description of nanofibril networks for which general models have been missing. It can be used to optimize nanofibril preparation and, hence, the resulting eco-friendly materials. [ABSTRACT FROM AUTHOR]

This study is centered on improving the mechanical and barrier characteristics of cellulose nanofibril films for food packaging applications. The goal was to induce fibril orientation, which was achieved by fabricating CNF films via an auto-dynamic sheet former (ADSF) at varying wire speeds, and varying CNF suspension solid contents. The wet-laid films were then dried using restrained (Z_Z shrinkage) and non-restrained (XY_Z) methods. Z_Z films demonstrated higher strength compared to XY_Z films at wire speeds of 1000 m/min and 1100 m/min. Films produced at 1100 m/min demonstrated the best oxygen barrier properties, irrespective of the drying technique employed. For 1100 m/min 0.1 wt.% films, the oxygen permeability values were decreased by 51.7% for the Z_Z shrinkage drying method and 40.3% for the XY_Z shrinkage drying method when compared to 900 m/min 0.1 wt.% films. The orientation of the film was assessed using polarized light microscopy (PLM) and wide-angle X-ray scattering (WAXS). However, these methods seemed to be limited to specific instances, as only a small area of the film could be imaged which did not provide a comprehensive indication of the overall alignment of the film, likely due to averaging of film's response to these techniques caused by their multi-layer structure. Future research could delve deeper into producing oxygen barrier packaging materials using similar formulations in a paper-forming machine. Additionally, a potential future study could explore depositing an aligned CNF layer directly onto the paper substrate to form sustainable food containers made of paper. [ABSTRACT FROM AUTHOR]

Micro- and nano-scale cellulosic fillers exhibit excellent dispersion and distribution within a thermoplastic matrix during the process of melt compounding or injection molding. In this study, spray-dried cellulose nanofiber (SDCNF) powders were manufactured using a pilot-scale rotating disk atomizer spray dryer. Bleached Kraft pulp (BKP), unbleached Kraft pulp (UKP), and old corrugated cardboard pulp (OCC) fibrillated at a fines level of 90% were used as feedstock materials for spray-drying. BKP-, UKP-, and OCC- SDCNFs were compounded with polypropylene using a twin screw co-rotating extruder. Maleic anhydride grafted polypropylene (MAPP) was used as a coupling agent in the composite formulations. The tensile, flexural, and impact properties of SDCNF-filled PP composites increased at 10 wt% SDCNF loading. The presence of SDCNFs in the PP matrix resulted in faster crystallization and a 12% reduction in the degree of crystallinity of the neat PP. The coefficient of thermal expansion (CTE) of neat PP was reduced by up to 31% attributable to the presence of the SDCNFs. Application of the SDCNF-reinforced PP composites in 3D printing reduced the shrinkage rate of the printed neat PP by 39%, and the printability of the PP was significantly improved with the addition of the SDCNFs. [ABSTRACT FROM AUTHOR]

Industrial residues that are not optimally utilized are removed by burning, landfilling, or dumping, which can threaten the environment and health. In fact, part of this agro-industrial waste still has content that has the potential to become raw material for value-added other industries. Dates by-product as residue of the fiber-rich fruit industry have the potential to be a source of nanocellulose. This study aims to obtain nanofibril cellulose (CNF) isolates from dates by-product via citric acid hydrolysis, and investigate the effect of acid concentration on the unknown dates by-product CNF isolate characteristics. Pretreatment such as delignification and bleaching is needed to obtain cellulose isolate with high purity. Furthermore, acid hydrolysis, centrifugation, and sonication are performed to obtain CNF. CNF isolates are characterized by the analysis of particle size distribution, morphology, and crystallinity. Analysis of functional groups and lignocellulose content test confirm that lignin and hemicellulose are degraded during isolation. The particle size distribution measurement shows that the greater the acid concentration, the smaller the CNF size and the better the size uniformity. The morphology of the CNF obtained is net-like fibers. The degree of crystallinity shown decreases with increasing acid concentration. This study revealed that different citric acid concentrations can result in different characteristics of CNF isolates.

In recent years, the extensive use of plastic packaging has caused serious environmental pollution problems. With the increase in people's environmental awareness, the development of new biodegradable food packaging materials to replace traditional petroleum-based plastics has become a hot research topic. Cellulose nanofibrils (CNF) are widely favored by researchers due to its excellent properties such as high specific surface area, elastic modulus, strength, and gas barrier properties. This paper summarizes the preparation methods of CNF and CNF composite films, discusses the mechanical property, barrier property, antibacterial property, degradable property, and responsive property as food packaging materials. Finally, the challenges faced by CNF in the field of food packaging are proposed, aiming to provide a reference for the future production of CNF food packaging materials to replace traditional petroleum-based materials.

The COVID-19 pandemic has brought concerns about the efficacy of respiratory protection equipment, primarily due to their widespread usage during this period. Among the various types of face masks, the N95, PFF3, and PFF2 surgical masks have gained great prominence due to their efficiency, despite the discomfort they may cause. Therefore, thinking of a cost-effective and more comfortable solution, this work aimed to reinforce non-woven face masks with cellulose nanofibrils (CNFs), to improve their filtration efficiency. For this, CNFs were produced using the mechanical processing of sugarcane bagasse (SCB) residues, which underwent plain alkaline pretreatment (CNF-PA) or alkaline pretreatment followed by enzymatic pretreatment (CNF-AE). It was observed that the CNF-AE films developed better characteristics regarding the contact angle, density, porosity, transmittance and transparency as well as vapor permeability compared to the CNF-PA films. The application of CNF on non-woven masks was performed using the spray technique. Bacterial filtration analysis showed filtration efficiency of 99.68% and 99.80% for masks that were coated with CNF-PA and CNF-AE, respectively. Whereas uncoated masks presented a filtration efficiency below 95%, which is the minimum required value. The masks obtained breathability values of 79.75 Pa/cm2 and 106.00 Pa/cm2 for CNF-AE and CNF-PA, respectively, whereas the uncoated masks showed values below 30.00 Pa/cm2. This work shows that the CNF obtained from SCB present good barrier capabilities and should be used for this purpose, especially on protective masks.

Light‐emitting diodes (LEDs) are widely used in lighting and display applications. Carbon quantum dots (CQDs), which have high biocompatibility, high resistance to photobleaching, and full‐spectrum luminescence, have inherent advantages as fluorescent materials for LED devices. Herein, multicolor CQDs are prepared by a new reagent engineering strategy due to the difference of effective conjugate length and the surface electron‐withdrawing groups of CQDs. White CQDs are realized by mixing blue, green, and red CQDs proportionally. Then, the aggregation‐caused quenching phenomenon of CQDs is suppressed through the hydrogen‐bonding network of cellulose nanofibrils (CNFs). Multicolor fluorescent films are prepared from CQDs and CNFs by simple mixing and casting methods. Finally, thin‐film encapsulation based on the photosensitive resin ABPE‐10 coating can be realized and rapidly assembles into fluorescent films with different light‐emitting colors into LED devices, leading to have superior thermal performance compared with conventional LEDs. White LEDs have excellent white‐light illumination performance, with Commission Internationale de L'Eclairage color coordinates of (0.33, 0.37), a correlated color temperature of 5688 K, and a color rendering index of 86. This strategy provides a convenient and scalable pathway for low‐cost, environmentally friendly, and high‐performance CQDs‐based LEDs. [ABSTRACT FROM AUTHOR]

With the increasing global demand for net-zero carbon emissions, actions to address climate change have gained momentum among policymakers and the public. The urgent need for a sustainable economy is underscored by the mounting waste crisis in landfills and oceans. However, the proliferation of distributed electronic devices poses a significant challenge due to the resulting electronic waste. To combat this issue, the development of sustainable and environmentally friendly materials for these devices is imperative. Cellulose, an abundant and CO2-neutral substance with a long history of diverse applications, holds great potential. By integrating electrically interactive components with cellulosic materials, innovative biobased composites have been created, enabling the fabrication of bulk electroactive paper and the establishment of new, potentially more sustainable manufacturing processes for electronic devices. This review explores recent advances in bulk electroactive paper, including the fundamental interactions between its constituents, manufacturing techniques, and large-scale applications in the field of electronics. Furthermore, it addresses the importance and challenges of scaling up production of electroactive paper, highlighting the need for further research and development. [ABSTRACT FROM AUTHOR]

Copyright of China Pulp & Paper is the property of China Pulp & Paper Magazines Publisher and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, the impact of incorporating cellulose nanofibrils (CNF) and carboxylated organo‐montmorillonite (OMMT), separately or in combination, into a UV‐curable wood coating was evaluated for performance enhancement. This study investigated the influence of nanoparticle loading percentage on the mechanical properties and thermal behavior of the coating, as well as the surface properties of digitally printed decorative wood‐based panels. The results indicated that the addition of CNF or OMMT increased the viscosity of the polymer solutions. Although CNF randomly oriented within the matrices, OMMT adhered to the surface of the polymer matrix. Chemical crosslinking was observed between CNF/OMMT and the coating. The addition of CNF and OMMT improved the thermal stability of the neat UV curing coating. The tensile strength of nanocomposite films with a 6 wt% loading of CNF increased significantly from 7.63 MPa to 12.73 MPa compared to pure films. The reinforcing effect of CNF on the tensile performance was significantly better than that of OMMT. Adding CNF to the matte coating slightly improved the clarity of the printed decorative panels. When CNF and OMMT were added together in the coating, there was a synergistic enhancement in the low gloss and high pencil hardness of the panels. Highlights: Both CNF and OMMT were chosen to achieve performance improvementsA simple filling method was adopted for preparation of reinforced coatingThe nanocomposite films exhibited fine thermal and mechanical propertiesThe better integrated property was obtained from the C + CNF3 + OMMT0.8 sampleThe physicochemical interaction of nanofiller with polymer molecule existed [ABSTRACT FROM AUTHOR]

The rechargeable zinc‐ion battery is regarded as a promising candidate for the next‐generation energy storage system, however, zinc dendrite growth and hydrogen evolution reaction (HER) have greatly hindered the practical application of the battery. Herein, a functionalized, nano‐engineering Zn2+ coordinated carboxylate cellulose solid‐state electrolyte (denoted as Zn‐CCNF@XG) for zinc‐ion battery is constructed through a straightforward approach. According to the experimental and density functional theory (DFT) results of dissociation energy, the notably decreased dissociation energy by −COOH is favorable to Zn2+ de‐coordinating and rapid ion‐hopping in Zn‐CCNF@XG to achieve high ionic conductivity and transference number. More importantly, the engineered molecular channels are beneficial to enlarging the distance between the nanofibril chains, providing a larger space for the movement of Zn2+. Benefiting from the coordination of Zn2+ with −OH in carboxylate cellulose nanofibrils, Zn‐CCNF@XG as a good ionic conductor displays a high ionic conductivity of 1.17 × 10−4 S cm−1 and transference number of 0.78. The Zn||NaV3O8·1.5H2O full cell with Zn‐CCNF@XG maintains a capacity retention of 83.46% with a coulombic efficiency of 99.99% after 3000 cycles (1 A g−1). The proposed strategy by introducing a functional group to cellulose nanofibrils effectively avoids the dendrite and HER, providing valuable guidelines for the practical application of zinc‐ion batteries. [ABSTRACT FROM AUTHOR]

Cellulose nanofibrils/poly(N-Isopropylacrylamide) semi-interpenetrating networks (MMCNF-PNAs) were synthesized using an in situ fabrication (semi-IPN). The polymerization of N-isopropylacrylamide (NIPAM) (free radical) was conducted in the presence of magnetic modified cellulose nanofibrils (MMCNFs). The adsorption behaviors and surface morphology of the synthesized adsorbents were investigated systematically. The adsorption behaviors of the as-prepared MMCNF-PNA towards methylene blue (MB, as the model contaminant) dye was studied, and the optimal adsorption conditions were also studied. The adsorption processes could be well fitted using pseudo-second-order and Elovich kinetic models. Meanwhile, Langmuir and Freundlich isotherm models were used to fit the adsorption which occurred at 25, 37 and 65 °C. The corresponding results showed that the Freundlich isotherm model fitted the adsorption process better, indicating that the dye's adsorption happened via heterogeneous adsorptive energies on the prepared MMCNF-PNAs. Their desorption and reusability were also studied to verify magnetic responsivity. To sum up, MMCNF-PNAs are promising magnetic and thermal stimuli-responsive adsorbents, showing a controlled adsorption/desorption process. [ABSTRACT FROM AUTHOR]

The colloidal layer formation on porous materials is a crucial step for printing and applying functional coatings, which can be used to fabricate anticounterfeiting paper. The deposition of colloidal layers and subsequent thermal treatment allows for modifying the hydrophilicity of the surface of a material. In the present work, wood-based colloidal inks are applied by spray deposition on spray-deposited porous cellulose nanofibrils (CNF) films. The surface modification by thermal annealing of the fabricated colloid-cellulose hybrid thin films is investigated in terms of layering and hydrophobicity. The polymer colloids in the inks are core–shell nanoparticles with different sizes and glass transition temperatures (Tg), thus enabling different and low thermal treatment temperatures. The ratio between the core polymers, poly-(sobrerol methacrylate) (PSobMA), and poly-(-butyl methacrylate) (PBMA) determines the Tg and hence allows for tailoring of the Tg. The layer formation of the colloidal inks on the porous CNF layer depends on the imbibition properties of the CNF layer which is determined by their morphology. The water adhesion of the CNF layer decreases due to the deposition of the colloids and thermal treatment except for the colloids with a size smaller than the void size of the porous CNF film. In this case, the colloids are imbibed into the CNF layer when Tg of the colloids is reached and the polymer chains transit in a mobile phase. Tailored aggregate and nanoscale-embedded hybrid structures are achieved depending on the colloid properties. The imbibition of these colloids into the porous CNF films is verified with grazing incidence small-angle X-ray scattering. This study shows a route for tuning the nanoscale structure and macroscopic physicochemical properties useful for anticounterfeiting paper. [ABSTRACT FROM AUTHOR]

The cationic cellulose nanofibrils demonstrate outstanding properties and have garnered extensive attention as sustainable materials. However, the large-scale preparation of cationic cellulose nanofibrils was limited since the high crystallinity of plant fibers made them harder to disintegrate and nanofibrillate. In this study, cationic cellulose nanofibrils, HKCF, were produced from softwood bleached kraft pulp (SWBK) with 2,3-epoxypropyltrimethylammonium chloride (EPTAC) by disk milling, followed by high-pressure homogenization. Morphologies and structures of cationic fibers (KCF and CCF) and homogenized products were characterized. The influence of cationization combined with high mechanical shear on the degree of substitution (DS) of cationic fibers was studied. At the same molar ratios of EPTAC to anhydroglucose units and holding time, the DS of KCF was higher than that of CCF. Compared with simple mixing induced by conventional stirring, the high mechanical shear induced by disk milling could increase the cationic efficiency of EPTAC by at least 50%. After high-pressure homogenization, KCF was completely fibrillated to HKCF with nano-scaled dimensions. HKCF dispersion showed a Bingham flow behavior and viscosity-dominating fluid-like behavior. Our study provides a facile and effective industrialized approach for producing highly substituted cationic cellulose nanofibrils. [ABSTRACT FROM AUTHOR]

One-pot syntheses and in situ ultrasonication have been optimized to generate tunable and highly hydrophobic 2,7-octadienyl-ether (ODE) cellulose nanofibrils (CNFs). Using only butadiene sulfone to serve as dual reaction medium and precursor to 1,3-butadiene (1,3-BD) for telomerization with cellulose hydroxyls, the OH-to-ODE conversion significantly improved from ca. 0.7 to 1.2, 1.8, 3.1, and 4.1 mmol of ODE/g-cellulose at 103-110 °C for 1-2 h. Ultrasonication was highly effective and versatile in the direct disintegration of ODE-cellulose (ODE-cell) in nonpolar organic solvents and plant oils into ODE-CNFs as well as pretreating cellulose for improved functionalization. Mixing 2 wt % in situ ultrasonicated 1.2 mmol of ODE/g-cell improved the modulus of polybutadiene six times and the strength of poly(styrene-b-isoprene-b-styrene) three times, whereas in situ ultrasonication of 1.8 mmol/g-cell directly with linseed oil at merely 0.07 wt % created holistic biobased hydrophobic cellulose paper to resist water penetration while also significantly improving the tensile strength. This optimized telomerization and streamlined in situ ultrasonication approach has presented a sustainable synthesis and processing strategy to generate highly hydrocarbon-compatible nanocelluloses previously unattainable.

With downward pressure on the value of almond hulls (AHs), the major byproduct from the largest tree nut crop globally, the streamlined production of several grades of cellulose nanofibrils (CNFs) toward novel aerogels with concurrent sugar extraction was introduced to synergistically drive these products toward commercial adoption. Hot water extraction produced 50% lignocellulose (LC) with equal water-soluble sugars from AH of a soft-shell variety. Aqueous NaOH and NaClO2/KOH treatments isolated ca. 15% alkali cellulose and 12% cellulose, respectively. Coupled 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) oxidation and blending yielded 88, 91, and 95% LC micro-/nanofibrils (LCMNFs), alkali cellulose nanofibrils (ACNFs), and cellulose nanofibrils (CNFs) with, respectively, 0.76, 1.02, and 0.84 mmol/g surface carboxyls in a similar 4:1 width-to-thickness aspect ratio and ultrahigh length-to-thickness aspect ratios (800-1900). The LCMNF aerogel was mostly wet-resilient, wet-stable, and dry/wet shape-recoverable, whereas the most charged ACNFs gave the stiffest aerogel [31.6 kPa/(mg/cm3)].

Extracellular vesicles (EVs), crucial in facilitating the transport of diverse molecular cargoes for intercellular communication, have shown great potential in diagnostics, therapeutics, and drug delivery. The challenge of developing effective preparation methods for EVs is heightened by their intrinsic heterogeneity and complexity. Here, a novel strategy for high EV enrichment is developed by utilizing EV‐affinitive‐modified cellulose nanofibrils. Specifically, modified cellulose with rich carboxyl groups has outstanding dispersing properties, able to be dispersed into cellulose nanofibrils in solution. These cellulose nanofibrils are utilized as scaffolds for the immobilization of EV‐affinitive antibody of CD63 by chemical conjugation. The CD63‐modified nanofibrils demonstrate a superior EV capture efficiency of 86.4% compared with other reported methods. The high performance of this system is further validated by the efficient capture of EVs from biological blood plasma, allowing the detection of bioactive markers from EV‐derived miRNAs and proteins. The authors envision that these modified cellulose nanofibrils of enhanced capability on EV enrichment will open new avenues in various biomedical applications. [ABSTRACT FROM AUTHOR]

Low-cost lignocellulosic filters were made from soybean hulls (SH), sugarcane bagasse fibers (SBF), cellulose nanofibers (CNF), and Kraft-bleached pulp (BP) as renewable feedstocks and applied in Cu (II) and Cd (II) removal from aqueous medium. Filtration was performed with a vacuum pump; filtration times ranged from 3 to 1200 seconds. For the same filter, the best permeate flow was 13,333 L.h.m-2 for both cations. The best Cd (II) removal (77.2 %) was achieved within 7 seconds at a permeate flow of 5,714 L.h.m-2. The same filter was also the best at removing Cu (II) (46.5 %), which was achieved within 7 seconds at a permeate flow of 5,714 L.h.m-2, as well. This short time evidenced that a long contact time is not needed to achieve higher removal. The best filter was made of BP, CNF, and SH. The presence of SBF and SH increased the contact angle and decreased the solid free energy surface. By FTIR-ATR it was possible to verify with which groups present in the chemical structures of the filter components the Cd (II) and Cu (II) cations interacted best. These results demonstrate the potential use of lignocellulosic biomass for producing composites aimed at water decontamination. [ABSTRACT FROM AUTHOR]

A high content of water is needed in traditional thermoplastic starch (TPS) processing to plasticize the starch and facilitate the processing, which leads to relatively low strength and modulus of the products and causes the issue of product aging partially due to the gradual water loss over time. In this work, based on the results from our previous study on lignin and cellulose nanofibril-reinforced TPS composites, a low content of citric acid (<0.5 wt%) was used to replace all the added water in the prior study (∼20 wt%). Citric acid demonstrated a much stronger viscosity-reducing effect than water and enabled composite processing at a very low acid content. The resultant nanocomposites exhibited much higher strength and modulus than those containing 20 wt% water as the processing aid. Fourier transform infrared spectrometry (FTIR) results showed strong interactions between the polar groups of starch and other ingredients. Scanning electron microscopy (SEM) photos indicated the disappearance of the two-phase "sea-island" morphology, suggesting the strong compatibilization effect of the acid. To lower the cost of the nanocomposites, we further replaced the starch and zein (an expensive biopolymer) components in the original composites with low-cost cornmeal. The new nanocomposites with cornmeal as the major ingredient exhibited similar processability and mechanical properties. With its low cost and high properties, this new type of agricultural byproduct-based nanocomposites is expected to be a promising material to replace synthetic polymers in many applications. [ABSTRACT FROM AUTHOR]

Pickering multiphase systems stabilized by solid particles have recently attracted increasing attention due to their excellent stability. Among various solid stabilizers, natural and renewable cellulosic micro/nanoparticles that are derived from agricultural and forestry sources have become promising candidates for Pickering stabilization due to their unique morphological features and tunable surface properties. In this review, recent progress on forming and stabilizing Pickering multiphase systems using cellulosic colloidal particles is summarized, including the physicochemical factors affecting their assembly at the interfaces and the preparation methods suitable for producing Pickering emulsions. In addition, relevant application prospects of corresponding Pickering multiphase materials are outlined. Finally, current challenges and future perspectives of such renewable Pickering multiphase systems are presented. This review aims to encourage the utilization of cellulosic micro/nanoparticles as key components in the development of Pickering systems, leading to enhanced performance and unique functionalities. [ABSTRACT FROM AUTHOR]

Pretreatment of pulp is a critical step in the fibrillation process to improve the quality and efficiency for cellulose nanofibril (CNF) production. This work employed a straightforward and entirely aqueous methacrylation and subsequent grafting-through polymerization technique to modify bleached softwood kraft pulp (BSKP). Specifically, methacrylate groups, poly(acrylamide) (PAM), and poly(methyl methacrylate) (PMMA) were chemically affixed to the surface of BSKP fibers, which was confirmed using FTIR spectroscopy. Bench-scale experiments were scaled up to pilot scale to prepare the modified BSKP samples, these were subjected to fibrillation using a Supermasscolloider (SMC), and the net cumulative energy (NCE) expended was monitored during the fibrillation process. Notably, the modified BSKP samples exhibited a substantial reduction in NCE, with the methacrylate modified BSKP sample achieving a 68% reduction in NCE expenditure to attain 90% fines as compared to the fibrillation of unmodified BSKP and producing methacrylate modified cellulose nanofibrils (Met-CNFs). Furthermore, we delved into the impact of polymeric surface modifications, both pre-and post-fibrillation, on fiber and fibril behavior, including the water retention value (WRV), hard-to-remove water (HR-Water), and rheological behavior. The attached polymer's hydrophilicity and hydrophobicity influenced the physical properties of the CNFs. Additionally, we executed a post-grafting polymerization process on the produced Met-CNFs. This additional step allowed us to modify nanofibril surfaces, yielding increased surface functionalization and producing modified CNFs that could be used for composite applications. [ABSTRACT FROM AUTHOR]

In the presented research, a facile, one-step method for the fabrication of cellulose nanofibrils/pectin (CNFs/PC) membranes is described, which were tested further for their ability to remove cationic dyes from the prepared model solutions. For this purpose, ten membranes were prepared with different quantities of CNFs and PC with/without citric acid (CA) or CaCl2 as mediated crosslinking agents, and they were characterised comprehensively in terms of their physical, chemical, and hydrophilic properties. All the prepared CNFs/PC membranes were hydrophilic with a Water Contact Angle (WCA) from 51.23° (without crosslinker) up to 78.30° (CaCl2) and swelling of up to 485% (without crosslinker), up to 437% (CaCl2) and up to 270% (CA). The stability of membranes was decreased with the increase in PC; thus, only four membranes (M1, M2, M3 and M5) were stable enough in water after 24 h, and these were additionally applied in the adsorption trials, using two structurally different cationic dyes, i.e., C.I. Basic Yellow 28 (BY28) and C.I. Basic Blue 22 (BB22), in four concentrations. The highest total surface charge of M3 (2.83 mmol/g) as compared to the other membranes influenced the maximal removal efficiency of both dyes, up to 37% (BY28) and up to 71% (BB22), depending on the initial dye concentration. The final characteristics of the membranes and, consequently, the dye's absorption ability could be tuned easily by changing the ratio between the CNFs and PC, as well as the type and amount of crosslinker. [ABSTRACT FROM AUTHOR]

Cellulose nanofibrils (CNF) can be modified to be used as a coating on food paper packaging. Previous research on PVA/CNF composites showed a low viscosity, which impacted their performance on the coating paper process. To overcome this problem, a thickening agent, such as carboxymethyl cellulose (CMC), is needed. In this work, the effect of CMC on PVA/CMC/CNF nanocomposites was investigated by varying the concentrations of CMC with PVA/CMC and CNF ratio of 80:20 and 90:10. The nanocomposites were characterized by their physical and tensile properties which could affect their coating performance. Moreover, the coating process was conducted on paper and the performances of the coated paper were studied. The results showed that the increase in CMC concentration led to an increasing viscosity and good zeta potential, suggesting good dispersion. Moreover, the addition of CMC improved the tensile properties of PVA/CMC/CNF nanocomposites. However, SEM analysis of PVA/CMC-1:CNF (80:20) revealed the occurrence of agglomeration which might influence the performance of the coated paper. Interestingly, PVA/CMC-1:CNF (80:20) had an excellent water resistance, with the lowest Cobb60. Moreover, the addition of CMC 1 wt% increased WVTR, which remained lower than the blank sample. Meanwhile, PVA/CMC-2:CNF (80:20) demonstrated the best performance in the oil absorption and tearing resistance test. In summary, the addition of CMC can effectively improve the physical and tensile properties of the PVA/CMC/CNF, as well as the barrier properties and tear strength of the PVA/CMC/CNF coated paper. The results demonstrate the potency of this material as a coating for food packaging paper. [ABSTRACT FROM AUTHOR]

The continuous development of electronic devices toward high-power and integrated directions has led to an increasing demand for renewable polymer composite materials with high thermal conductivity and electrical insulation to solve the problem of overheating in electronic devices. Cellulose is inherently insulating, with insufficient thermal conductivity. Although boron nitride nanosheets (BNNSs) have excellent thermal conductivity, hexagonal boron nitride (h-BN) ligands in their raw state are prone to aggregation, which limits their performance. In this work, h-BN was first ball-milled and amino-modified, and then, carboxylated nanofibrillated cellulose (COOH-CNF) was used to disperse the BNNSs. With the help of amide bonding, the BNNSs were uniformly dispersed in the nanocellulose (CNF) matrix; this reduced the aggregation and the presence of voids between the BNNSs and promoted the construction of effective thermal channels. The resulting composite slurry was stably dispersed and could be filtered to form a film; the best overall performance was achieved for a BNNS loading of 30% with a thermal conductivity (TC) of 9.00 W·m–1·K–1 (pure CNF 1.88 W·m–1·K–1). In addition, the volume resistivity reached 9.38 × 1013 Ω·cm (pure CNF of 2.53 × 1013 Ω·cm) and the electrical strength reached 22.67 kV·mm (17.04 kV·mm for CNF). Our results showed that the BNNS-CNF composite film had high TC and excellent insulating properties; therefore, its application in the thermal management of electronic devices has broad application prospects. [ABSTRACT FROM AUTHOR]

In this study, high-purity cellulose nanofibrils (CNFs) were environmentally friendly extracted from natural bamboo. Physical, chemical, and mechanical treatments were comprehensively investigated, and then ensembled to effectively and efficiently remove lignin and hemicellulose with low energy from raw bamboo fibers, which combine microwave liquefaction, hydrogen peroxide-acetic acid delignification, alkaline treatment, and along with acid hydrolysis. This was able to allow for the extraction of CNFs. Compositional analysis, Fourier-transform infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and thermogravimetric analysis were performed to investigate and confirm the successful removal of undesirable lignin and hemicellulose. The resultant cellulose fibers were then subjected to a mechanical treatment to obtain the cellulose nanofibrils. It was found that the obtained CNFs have an average diameter of 13 nm with a cellulose purity of 94.52%. Without any further surface modification, the incorporation of bamboo-based CNFs into natural rubber (NR) exhibits significant improvement in their mechanical properties including modulus (~66.67%), tensile strength (~120.83%), toughness (~139.34%), and elongation at break (~31.41%). Interestingly, there is no compromise between tensile strength and elongation at break for the nanocomposites. DMA results also showed that both storage and loss moduli were dramatically enhanced over those of neat NR in their glassy region, which is typically unusual. This study can show, if optimized for material extraction, the great promise to the potential use of natural materials to develop environmentally friendly composites with multi-functionality in a variety of real-world engineering structural applications. [ABSTRACT FROM AUTHOR]

Copyright of China Pulp & Paper is the property of China Pulp & Paper Magazines Publisher and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Light‐emitting diodes (LEDs) are widely used in lighting and display applications. Carbon quantum dots (CQDs), which have high biocompatibility, high resistance to photobleaching, and full‐spectrum luminescence, have inherent advantages as fluorescent materials for LED devices. Herein, multicolor CQDs are prepared by a new reagent engineering strategy due to the difference of effective conjugate length and the surface electron‐withdrawing groups of CQDs. White CQDs are realized by mixing blue, green, and red CQDs proportionally. Then, the aggregation‐caused quenching phenomenon of CQDs is suppressed through the hydrogen‐bonding network of cellulose nanofibrils (CNFs). Multicolor fluorescent films are prepared from CQDs and CNFs by simple mixing and casting methods. Finally, thin‐film encapsulation based on the photosensitive resin ABPE‐10 coating can be realized and rapidly assembles into fluorescent films with different light‐emitting colors into LED devices, leading to have superior thermal performance compared with conventional LEDs. White LEDs have excellent white‐light illumination performance, with Commission Internationale de L’Eclairage color coordinates of (0.33, 0.37), a correlated color temperature of 5688 K, and a color rendering index of 86. This strategy provides a convenient and scalable pathway for low‐cost, environmentally friendly, and high‐performance CQDs‐based LEDs.

Low-cost lignocellulosic filters were made from soybean hulls (SH), sugarcane bagasse fibers (SBF), cellulose nanofibers (CNF), and Kraft-bleached pulp (BP) as renewable feedstocks and applied in Cu (II) and Cd (II) removal from aqueous medium. Filtration was performed with a vacuum pump; filtration times ranged from 3 to 1200 seconds. For the same filter, the best permeate flow was 13,333 L.h.m-2 for both cations. The best Cd (II) removal (77.2 %) was achieved within 7 seconds at a permeate flow of 5,714 L.h.m-2. The same filter was also the best at removing Cu (II) (46.5 %), which was achieved within 7 seconds at a permeate flow of 5,714 L.h.m-2, as well. This short time evidenced that a long contact time is not needed to achieve higher removal. The best filter was made of BP, CNF, and SH. The presence of SBF and SH increased the contact angle and decreased the solid free energy surface. By FTIR-ATR it was possible to verify with which groups present in the chemical structures of the filter components the Cd (II) and Cu (II) cations interacted best. These results demonstrate the potential use of lignocellulosic biomass for producing composites aimed at water decontamination.

The recent FDA decision to eliminate animal testing requirements emphasises the role of cell models, such as spheroids, as regulatory test alternatives for investigations of cellular behaviour, drug responses, and disease modelling. The influence of environment on spheroid formation are incompletely understood, leading to uncertainty in matrix selection for scaffold-based 3D culture. This study uses atomic force microscopy-based techniques to quantify cell adhesion to Matrigel and cellulose nanofibrils (CNF), and cell-cell adhesion forces, and their role in spheroid formation of hepatocellular carcinoma (HepG2) and induced pluripotent stem cells (iPS(IMR90)-4). Results showed different cell behaviour in CNF and Matrigel cultures. Both cell lines formed compact spheroids in CNF but loose cell aggregates in Matrigel. Interestingly, the type of cell adhesion protein, and not the bond strength, appeared to be a key factor in the formation of compact spheroids. The gene expression of E- and N-cadherins, proteins on cell membrane responsible for cell-cell interactions, was increased in CNF culture, leading to formation of compact spheroids while Matrigel culture induced integrin-laminin binding and downregulated E-cadherin expression, resulting in looser cell aggregates. These findings enhance our understanding of cell-biomaterial interactions in 3D cultures and offer insights for improved 3D cell models, culture biomaterials, and applications in drug research.

2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO) and its derivatives are well-established catalysts for various oxidation processes, despite its hazardous nature, causing harm to aquatic ecosystems. Thus, the reuse of TEMPO with a sustained high activity has gained significant importance for its industrial application, which has led to the development of supported TEMPO catalyst. In this context, the efficiency of the support process acquires high relevance. Therefore, this research is aimed at the improvement of the TEMPO supported on silica magnetically modified with Fe3O4 through the application of an online Fourier transform infrared spectroscopy (FTIR) probe to monitor its synthesis. FTIR effectively controlled the synthesis of supported TEMPO, by tracking online the concentration of 3-aminopropyltriethoxysilane (APTES) and tetraethyl orthosilicate (TEOS). Additionally, the presence of Fe3O4 particles in the core of the catalyst allowed its convenient recovery and subsequent reuse. Furthermore, the supported TEMPO catalyst was successfully applied in the oxidation of cellulose to produce nano/microfibrils. The carboxyl groups of the initial untreated cellulose increase from 0.05 mmol/g to 0.68 mmol/g with the supported TEMPO catalyst in presence of sodium hypochlorite and sodium bromide at 50 °C.

This study assessed the effects of cellulose nanofibrils (CNFs) and multi-walled carbon nanotubes (MWCNTs) on lung inflammation in a cigarette smoke-induced chronic obstructive pulmonary disease (COPD) mouse model. Prior to instillation, COPD model mice displayed distinctive cellular compositions and elevated cytokine levels in bronchoalveolar lavage fluid (BALF). After intratracheal instillation of 80 μg CNFs, no significant histopathological changes, BALF composition alterations, or cytokine level shifts were observed on day 28. This suggests minimal lung impact and no interference with reducing smoke-induced inflammation. In contrast, the instillation of 80 μg MWCNTs resulted in significant histopathological changes, increased cellular composition, and elevated cytokine levels in BALF on day 28. These findings indicate that CNF exposure had little effect on the lungs and did not impede the reduction of smoke-induced inflammation, while MWCNT exposure hindered the attenuation of pulmonary inflammatory response. The study emphasizes the importance of considering diverse cases, including individuals with pre-existing respiratory conditions, when assessing occupational safety and health risks associated with advanced nanomaterial exposure.

We review the recent progress that have led to the development of porous materials based on cellulose nanostructures found in plants and other resources. In light of the properties that emerge from the chemistry, shape and structural control, we discuss some of the most promising uses of a plant-based material, nanocellulose, in regenerative medicine. Following a brief discussion about the fundamental aspects of self-assembly of nanocellulose precursors, we review the key strategies needed for material synthesis and to adjust the architecture of the materials (using three-dimensional printing, freeze-casted porous materials, and electrospinning) according to their uses in tissue engineering, artificial organs, controlled drug delivery and wound healing systems, among others. For this purpose, we map the structure–property–function relationships of nanocellulose-based porous materials and examine the course of actions that are required to translate innovation from the laboratory to industry. Such efforts require attention to regulatory aspects and market pull. Finally, the key challenges and opportunities in this nascent field are critically reviewed.

Cellulose nanofibrils (CNFs) are ideal Pickering emulsion stabilizers, but they have limitations due to their strong hydrophilicity. In this work, modified CNFs (M-CNFs) with a water contact angle of 93.1 ± 0.6° were successfully prepared by methyl trimethoxysilane. Subsequently, the performance of the M-CNFs was characterized by crystallization performance determination (XRD), Fourier transform infrared spectra (FTIR), particle size determination, thermogravimetric analysis and so on. As well as, the O/W Pickering emulsions prepared with M-CNFs as a stabilizer has good performance in the diameter and particle size distribution, most droplet sizes can be maintained within 5 μm, and unimodal distribution was presented. It can show more stable performance under medium and alkaline conditions (pH = 7–11), and has certain anti-ion ability. Thus, this study has potential applications in coating, paint, sewage treatment and other fields. [ABSTRACT FROM AUTHOR]

The aim of our work is the preparation of cellulose nanofibrils or nanocrystals made from cellulose that is recovered from sugarcane bagasse agricultural waste (SC) as a dispersant instead of commercial cellulose for oil spill cleanup. In the current study, carboxymethyl cellulose was prepared by cellulose mercerization, which was then esterified by oxalic acid to create nanocellulose. Incorporation of oxalate into carboxymethyl cellulose (CMC) was verified by 1H‐NMR spectroscopy by the appearance of a new peak at 8.15 ppm for CMC–oxalate. The degree of substitution (DS) of oxalate was 0.17. The synthesized nanocellulose formed particles were roughly the same size and shape as both cellulose nanofibrils (CNFs) and cellulose nanocrystals (CNCs): measuring 321–480 nm in length and 4–5 nm in width. Emulsions of paraffins made from CMC–oxalate are stable up to 10 months without undergoing precipitation. CMC–oxalate had great thermal stability and worked well as a paraffin oil dispersant. CMC–oxalate provided a barrier around the oil droplet surface, which prevented droplets from coalescing. This hypothesis is supported by the contact angle measurement for the O/W emulsion formed by CMC–oxalate being 0°, which is lower than the value for emulsions formed by underivatized CMC, 37.20°. From transmission electron microscopy observations, O/W emulsions of paraffin oil were spherical in shape, and separated from each other by a distance of 30–100 nm. This study shows that CMC–oxalate can be prepared by a low‐cost method, yielding nanocellulose with characteristics that resemble CNFs and CNCs, thereby opening up new potential applications for cellulose nanomaterials. [ABSTRACT FROM AUTHOR]

Three types of wood pulp feedstocks including bleached softwood kraft, unbleached softwood kraft and old corrugated containers were disk refined to produce cellulose nanofibrils at different fineness levels ranging from 50 to 100%, and the resulting aqueous suspensions of cellulose nanofibrils were spray dried. The spray drying experiments were carried out to examine different processing conditions for the different CNF feedstock types and fines level at various suspension concentrations to produce dry samples with free-flowing powder morphologies. The fineness levels and solids contents of CNF suspensions were set to 80% or more and 1.8% or less, respectively. If the solids content of the CNF solutions was high and the fibrillation level was low, plugging was experienced in the spray head because of the high viscosity of the suspensions, resulting in production of poor-quality powders. In terms of reduction in processing energy, even if the CNF suspension solids content was increased to 1.5 wt.%, the powder quality and the production yields were excellent. It was confirmed that high-quality powder under 20 µm were produced at a 90% fibrillation level of all CNF feedstocks. The resulting dry CNF powders were characterized to determine particle size distributions and morphological properties via a scanning electron microscope and a laser diffraction particle size analyzer. The particle sizes were smaller at higher fibrillation levels and lower solids content of the CNF suspensions. The CNF suspension derived from bleached kraft pulp, the average particle size decreased by 43% and 33% with the lowered solids contents from 1.8 to 1%, and the increased fineness levels from 80 to 100%, respectively. [ABSTRACT FROM AUTHOR]

In this study, radiation-induced admicellar polymerization of methacrylic acid (MAA) onto the surface of cellulose nanofibrils (CNFs) was conducted. The aim of the study was to use radiation-induced admicellar polymerization of MAA to obtain pH-responsive CNFs. The chemical, physical, and morphological changes of CNF-grafted poly(methacrylic acid) (PMAA) were studied at various absorbed radiation doses (10–50 kGy) and MAA concentrations (0.5–1.5 M). In addition, the change in absolute zeta value of CNF-grafted-PMAA with different concentrations of PMAA grafted was measured at pH values varied from 3 to 11. The results show that 20 kGy is a sufficient gamma irradiation dose in the inert condition as proved by the highest carboxyl concentration obtained. Grafting was demonstrated by an FTIR band, specifically at 1689 cm−1, corresponding to the carbonyl stretching vibration of the carboxyl group. The cross-section of a single CNF showed an increment in diameter, with the increased amount of PMAA concentration. TGA analysis of dipole–dipole interactions and hydrogen bonding showed that admicellar polymerization was successful. Meanwhile, PMAA amorphous reduced the crystallinity index of CNFs. The absolute zeta value decreased from pH 3 to pH 9, then increased proportionally until reaching pH 11. This research shows that radiation-induced admicellar polymerization is a viable method for grafting nanosurfaces, and it can be applied to a wide variety of nanoparticles. [ABSTRACT FROM AUTHOR]

Synthetic packaging has excellent performance, but most of them becomes a waste after their use and thus, poses serious concerns to the environment and consumer health. Considering current circumstances, the demand for sustainable packaging that is either recyclable or biodegradable if discarded has increased tremendously in last few years. Cellulose nanofibril (CNF) films are emerging as a sustainable packaging; however, their high energy consumption associated with the production of fibres and reduced properties on recycling are serious concerns. The aim of this study is to assess the recycling characteristics of spray deposited CNF films. For this purpose, the CNFs were recycled at different revolutions (75 × 103 to 999 × 103) in a laboratory disintegrator, followed by screening and their physical, barrier and environmental characteristics were evaluated. Results showed that recycled CNF films at 300 × 103 revolutions had identical barrier performance as compared with the non-recycled films. Additionally, the films after first recycling have maintained their mechanical properties without compromising their dimensional stability. However, the mechanical performance and transmittance of these films after the 2nd recycling have slightly reduced due to the agglomeration of the fibres as affirmed by the SEM images. The CNF films showed slightly higher environmental impact in terms of their embodied energies than conventional packaging; however, these impacts are expected to be lower on possibly further recycling of these films. The ease of recycling of these films without compromising the dimensional stability is an excellent route to contribute towards global sustainability. [ABSTRACT FROM AUTHOR]

This study deals with the development of 3D printable bionanocomposites using poly(lactic acid) (PLA) with ≤ 2% D-lactic acid content and cellulose nanofibrils (CNFs). The CNFs were extracted from the waste sawdust of Eucalyptus grandis via chemical and mechanical techniques. Thermogravimetric analysis (TGA) revealed that the CNFs were thermally stable within the intended processing temperature ranges. In this study, a combination of solvent casting and melt extrusion techniques was adopted in the production of PLA containing 1 wt% and 3 wt% CNFs. The neat PLA filament was brittle and frequently broke during fused deposition modelling (FDM) 3D printing. However, the incorporation of triacetin as a green plasticizer resulted in improved filament flexibility and eliminated the inherent brittleness. TGA analysis revealed a slight reduction in the degradation temperature of the bionanocomposites when compared to neat polymer; however, all the specimens were thermally stable within the processing temperature. The scanning electron microscopy images of the 3D printed specimens revealed the presence of voids across the fracture surfaces. The tensile analysis of 3D printed specimens revealed that the PLA/CNF bionanocomposites exhibited higher tensile modulus, and elongation (strain) when compared to PLA-based specimens. The tensile strength of the 3D-printed 1 wt% bionanocomposite specimen was 12% higher than that of the neat specimen, whereas the 3 wt% bionanocomposite remained comparable to neat PLA. In summary, the morphological, tensile and 3D printing analysis revealed that the bionanocomposite filaments possessed adequate roundness, flexibility, and strength. The as-prepared filaments performed well under low printing temperatures without warping. [ABSTRACT FROM AUTHOR]

This work presents a review related to the obtainment of cellulose from different structures in agro-industrial residues, both for application in the food industry and for the reinforcement of other materials. Cellulose nanofibers are produced by the heart of palm (Bactris gasipaes) industry in Brazil and are used as a stabilizer in avocado oil emulsions; conversely, cellulose nanocrystals are produced in waste from the tequila industry (Agave tequilana Weber var. Azul) in Jalisco, Mexico, and are used for reinforcement applications. [ABSTRACT FROM AUTHOR]

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Cellulose nanofibrils (CNFs) from hardwood bleached kraft pulp (HwBKP) are produced via enzymatic, chemical, and mechanical treatment. A nanoporous structured CNF-based separator is produced, and the electrochemical performance, morphology, and thermal stability analyses are performed in comparison to the commercial polyethylene separator. The results obtained show that the electrolyte-philic CNF separator has capacity retention of 88.6% over 200 cycles and very good ionic conductivity and wettability results due to its high hydrophilic nature. At 140°C, the CNF separator was resilient to heat and remained intact. The CNF separator reflects high thermal resistance and good electrolyte uptake properties that are among the mandatory requirements of a separator hence, a promising contender for use in lithium-ion batteries. [ABSTRACT FROM AUTHOR]

Three-dimensional (3D) tumor spheroids are regarded as promising models for utilization as preclinical assessments of chemo-sensitivity. However, the creation of these tumor spheroids presents challenges, given that not all tumor cell lines are able to form consistent and regular spheroids. In this context, we have developed a novel layer-by-layer coating of cellulose nanofibril–polyelectrolyte bilayers for the generation of spheroids. This technique builds bilayers of cellulose nanofibrils and polyelectrolytes and is used here to coat two distinct 96-well plate types: nontreated/non-sterilized and Nunclon Delta. In this work, we optimized the protocol aimed at generating and characterizing spheroids on difficult-to-grow pancreatic tumor cell lines. Here, diverse parameters were explored, encompassing the bilayer count (five and ten) and multiple cell-seeding concentrations (10, 100, 200, 500, and 1000 cells per well), using four pancreatic tumor cell lines—KPCT, PANC-1, MiaPaCa-2, and CFPAC-I. The evaluation includes the quantification (number of spheroids, size, and morphology) and proliferation of the produced spheroids, as well as an assessment of their viability. Notably, our findings reveal a significant influence from both the number of bilayers and the plate type used on the successful formation of spheroids. The novel and simple layer-by-layer-based coating method has the potential to offer the large-scale production of spheroids across a spectrum of tumor cell lines. [ABSTRACT FROM AUTHOR]