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Polyhydroxyalkanoates (PHA) is a carbon neutral material that contributes to reducing greenhouse gas emissions due to manufactured from biomass and easily degraded by the enzymatic effects of microorganisms in the natural environment. However, PHA exhibits poorer mechanical properties and processability compared with petroleum‐based plastics. This study used cellulose nanofiber (CNF) to improve limit of PHA. Moreover, CNF was silylated to reduce polarity difference with PHA and enhance the dispersibility of nanocellulose at PHA. At a result, the silylation process was successfully performed by Si‐CH3 stretching peaks in Fourier transform infrared spectroscopy spectra and hydrophobicity of TEOS‐MTES‐CNF (TECNF) was confirmed by observed water contact angle (147°). In addition, nanostructure of TECNF was maintained during silylation and drying process through field emission scanning electron microscopy. Moreover, the PHA/TECNF composite showed enhanced processability, and tensile strength was increase almost 37% (0.52 MPa) compared with PHA. Oxygen transmission rates (300 cc/m2۰day) and single lap shear strength (225 kPa) were determined to be at least equivalent or superior to those of commercial packaging materials. Therefore, TECNF could be considered as a reinforcing agent, nucleating agent, and plasticizer in PHA. Also, this composite has possibilities to using as environmentally friendly packaging materials. [ABSTRACT FROM AUTHOR]

The honeycomb structure stands out as an exemplary material, characterized by its remarkable combination of lightweight and superior mechanical strength. Drawing inspiration from the roles of cellulose nanofiber and lignin in natural wood, a novel high‐stiffness biomass honeycomb nanocomposite is developed. This composite is engineered by incorporating lignin into bacterial cellulose, followed by the self‐polycondensation of lignin at elevated temperature. The nanocomposite architecture features intricately interwoven nanofibers to provide a robust long‐range framework, while the self‐polymerized lignin through coniferyl alcohol radicals serves as a rigid binder that interlinks the nanofibers. The dual mechanisms endow the material with exceptional tensile strength and rigidity. Molding this nanocomposite into a honeycomb structure yields a material with outstanding mechanical properties that outperform commercial alternatives, including those derived from Nomex paper and aluminum alloys. Given its characteristics, this nanocomposite holds great promise as a substrate for the next generation of high‐performance structural materials. [ABSTRACT FROM AUTHOR]

In this study, we demonstrated that adding 0.05 wt.% cellulose nanofibers (CNFs) to CNFpoly(methyl methacrylate) (PMMA) composite materials enhanced hardness, toughness, and maximum flexural strength, surpassing commercially available PMMA variants. Furthermore, CNF addition substantially improved PMMA's wear resistance, reducing wear volume through increased hardness and CNF's lubricating effect. The observed variation in slope in the wear volume versus dissipated energy plot suggests different wear mechanisms, and the potential to serve as a sensor for detecting wear interface behavior. [ABSTRACT FROM AUTHOR]

A novel solar steam generator featuring divergent microchannels (SSG‐DM) is developed via directional freezing of a polypyrrole (PPy)–cellulose nanofiber (CNF) suspension in an inverted frustum mold. Contrary to the conventional 3D SSGs characterized by random micropores (SSG‐RM), SSGs incorporating vertical microchannels (SSG‐VM), fabricated through directional freezing procedure, demonstrate increased evaporation performance due to enhanced water transport to the top surface. However, SSG‐VM manifests a limitation in the form of reduced salt resistance on its side surfaces where water transport is restricted. This issue is addressed by directional freezing of a PPy–CNF suspension in an inverted frustum mold, followed by freeze‐thawing gelation in an AlCl3 solution. The fabricated SSG features divergent microchannels that spanned from the bottom surface to the top and side surfaces, with a gradual increase in diameter. The evaporation rate of SSG‐DM is recorded at 2.42 kg m−2h−1 under 1‐sun illumination; this rate further increases to 15.73 kg m−2h−1 in the presence of a 4 m s−1 wind. Notably, SSG‐DM demonstrates excellent salt resistance in highly saline brine (10 wt%) under windy conditions (4 m s−1), whereas SSG‐RM and SSG‐VM are ineffective under the same conditions. [ABSTRACT FROM AUTHOR]

BACKGROUND RESULTS CONCLUSION Cellulose nanofiber (CNF) is an ideal Pickering emulsion stabilizer because of its high aspect ratio and flexibility. CNF was hydrophobically modified by dodecenyl succinic anhydride and used to stabilize the simulated food emulsion system containing insect protein. The prepared dodecenyl succinate nanofiber (D‐CNFs) was characterized by contact angle and laser particle size analyzer. The stability of the emulsion system under different conditions was characterized by zeta potential and appearance observation. Lastly, in vitro digestion simulation experiments were carried out to investigate whether the addition of D‐CNFs had an effect on the digestion and absorption of oil.The modification process for dodecenyl succinic anhydride to CNFs was that the system temperature was 40 °C, the system pH value was 8.5 and the reaction time was 6 h. The water contact angle of the modified CNFs increased to 83.2 ± 0.9°. D‐CNFs were introduced into the simulated food emulsion system containing insect protein. The increase in the concentration of D‐CNFs in the aqueous phase promoted the stability of the simulated emulsion system. Increasing the ratio of insect protein was not conducive to the stability of the emulsion. The final fat digestibility of the emulsion with D‐CNFs was lower than that of the emulsion without D‐CNFs.Overall, the analysis and characterization results show the potential of the modified CNF as a food simulant emulsion stabilizer containing insect protein, which can be used for the development of specific functional foods. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Carbon electrodes are widely used for battery and electrolysis due to wide potential window and chemical stability. The carbon electrode made from carbon material ink using printing process is expected as electrode with low cost and large area. Therefore, we have developed carbon material inks and printed electrode by combining micro-wave treated graphite oxide (MwGO) and screen-printing method. However, the MwGO electrodes exhibited low water resistance. Cellulose nanofiber is mixed into the MwGO ink to improve water resistivity. As a result, increase in water resistance is achieved with maintaining electrical conductivity. [ABSTRACT FROM AUTHOR]

Cellulose-based film has gained popularity as an alternative to synthetic polymers due to its outstanding properties. Among all types of cellulose materials available, cellulose nanofiber (CNF) has great potential to be utilized in a diverse range of applications, including as a film material. In this study, CNF biocomposite film was prepared by using polyvinyl alcohol (PVA) as a matrix and Uncaria gambir extract as a filler. This study aims to investigate the effect of Uncaria gambir extract on the optical properties and thermal stability of the produced film. The formation of the CNF biocomposite films was confirmed using Fourier Transform Infrared Spectroscopy, their transmittance characteristics were measured using UV-Vis spectroscopy and a transmittance meter, while their reflectance was determined using a reflectance meter. The results revealed that the addition of Uncaria gambir extract to the CNF biocomposite film improved its UV-shielding properties, as indicated by the lower percentage of transmittance in the visible region, 10%–70%. In addition, its reflectance increased to 10.6% compared to the CNF film without the addition of Uncaria gambir extract. Furthermore, the thermal stability of the CNF biocomposite film with the addition of Uncaria gambir extract improved to around 400°C–500°C. In conclusion, the results showed that CNF biocomposite film prepared by adding Uncaria gambir extract can be a promising candidate for optical and thermal management materials. [ABSTRACT FROM AUTHOR]

Cellulose nanofibers (CNFs) are part of organic crystallization macromolecular compounds that can be found in bacteria's capsular polysaccharides and plant fibers. CNFs have a lot of potential as suitable matrices and advanced materials, and there have been a lot of studies done on them so far, both in terms of modifying them and inventing uses for them. In this paper, CNFs/reduced graphene oxide (GO) (rGO) nanocomposites were developed to create renewable, flexible, and cheap humidity sensors. The composite film's performance as a humidity sensor was evaluated by analyzing the variations in capacitance at different humidity levels. The synthesized composite film underwent characterization using various analytical techniques, including scanning electron microscopy (SEM), UV (ultraviolet)/Vis (visible) spectrophotometry, Fourier transform infrared spectroscopy (FTIR), and thermomechanical analysis (TMA). The sensing mechanism is elucidated based on hydrophilic functional groups within the composite material. It has been observed that 3 wt% rGO/CNF composite is the best suited for humidity sensing among all other samples. [ABSTRACT FROM AUTHOR]

Highly electro‐responsive soft actuators have aroused immense attention due to their large bending deformation, fast response time, and long durability under low driving voltage. Herein we present a high‐performance ionic soft actuator using carboxylated cellulose nanofiber (CCNF), ionic liquid (IL), and polyvinyl alcohol (PVA). The proposed actuator displayed excellent actuation performances such as a large bending strain of 0.41% (peak‐to‐peak displacement of 13.6 mm), specific capacitance up to 43%, long working ability (95% maintain for 2.5 h), significantly reduced phase delay, and broad frequency bandwidth (0.1–3.0 Hz), all of which were ascribed to the strong ionic interactions of CCNF with PVA and IL. Simultaneously, bionic applications of the actuators were achieved including the active stent, bionic gripper, and bionic fingers for sliding electronic photos and human‐robot interactions. Thus, the proposed actuator provides a way for the advancement of next‐generation artificial muscles, soft robots, and human‐robot interactions. Highlights: Preparing an electro‐ionic actuator using carboxylated cellulose nanofibers.Ionic interactions and cross‐linking promoting ion transport capability.The actuator displaying excellent actuation responses and bioinspired applications. [ABSTRACT FROM AUTHOR]

Cellulose nanofiber–blended polylactic acid composites were prepared to enhance biodegradable polymers, which are expected to be a viable solution to the recent plastic waste crisis. The cellulose nanofibers were prepared by extracting cellulose fibers from bamboo using high-temperature and high-pressure steam and then disintegrating the fibers to the nanoscale. The optimum conditions for the processing pressure of the high-temperature and high-pressure steam treatments and the extraction process grinding time were investigated. Furthermore, the mixing ratio of cellulose nanofibers and polylactic acid for the fabrication of the composites was examined. The results show that the best condition was a 1:1 (50 wt% CNF) blend of cellulose nanofibers made with 15 atm of steam pressure for 5 min of steaming time followed by 10 s of milling time to make composites with polylactic acid that had 2.35 times the strength (77.5 MPa/g/cm3) of polylactic acid alone (33.3 MPa/g/cm3). This indicates that cellulose nanofibers produced from bamboo using high-temperature and high-pressure steam treatments can be used as reinforcing materials for low-strength biodegradable polymers. [ABSTRACT FROM AUTHOR]

In this study, we investigated the effects of repeated freeze-thaw cycles on the mechanical, and structural properties of cellulose nanofiber-reinforced poly(vinyl alcohol) composite hydrogel with borax as a crosslinking agent. Repeated freeze-thaw cycles significantly improved the mechanical performance of the composite hydrogels and enhanced the gel fraction. They improved not only the mechanical strength but also the stretchability of the composite hydrogels: the composite subjected to five- and ten-FT cycles exhibited an elongation of ~ 1100% and a tensile strength of 2 MP. In addition, the composite hydrogels exhibited tearing energies of 2.8–6.6 kJ m−2, which are a few hundred times larger than those of normal hydrogels (~ 0.01 kJ m−2) and are comparable to those of double network gels known as tough gels (typically 1–3 kJ m−2). Repeated freeze-thaw cycles greatly contributed to the development of poly(vinyl alcohol) crystals and the formation of porous polymer networks, which are suitable for biomaterials, such as cell scaffolds. Fluorescent microscopy revealed the adhesion of cells on cellulose nanofiber/poly(vinyl alcohol) composite hydrogels cultivated with umbilical cord mesenchymal stem cells. [ABSTRACT FROM AUTHOR]

This study delves into the synthesis and characterization of cellulose nanofibers (NFCs) and their nanobiocomposites incorporating coinage nanoparticles ( Ag,ZnO, and CuO ). NFCs were derived from oil palm empty fruit bunches, yielding fibers with diameters below 5 nm. Silver nanoparticles were synthesized using a reduction method, resulting in spherical particles sized between 10-25 nm. The integration of these nanoparticles into the NFCs matrix was confirmed through SEM, TEM, FT-IR, and XRD analyses. FT-IR spectrum of cellulose nanofibers exhibited peaks at 3399 − 3164 cm^−1 for hydroxyl groups, 2925 − 2812 cm^−1 for the cellulose skeleton, and 1013 cm^−1 for the -C-O-C/-C-O-H group. Significant changes were observed in the spectrum post-nanoparticle addition, notably at 1412 and 1317 cm^−1. SEM analysis revealed microdomains of metallic nanoparticles dispersed within the cellulose nanofiber matrix, contributing to increased molecular orientation and crystallinity index. The crystallinity index of cellulose nanofiber films varied: NFC alone exhibited 76.27%, NFC − ZnO 78.54%, NFC-CuO 77.34%, NFC-Ag 76.29%, and NFC-All 77.95%. These variations directly impacted the mechanical properties of the nanobiocomposites, which exhibited significant improvements. Biological analysis confirmed antimicrobial efficacy against E. coli, S. aureus, and C. albicans due to the presence of metallic nanoparticles. Furthermore, water vapor permeability assessments concluded that the nanobiocomposites are suitable for food packaging applications. These findings underscore the promise of NFC-based nanobiocomposites with coinage nanoparticles for advanced packaging materials. Future research avenues should focus on optimizing nanoparticle loading, refining dispersion techniques, and exploring further applications for these versatile nanobiocomposites.

Finger joints are one of the most important and widely used joints in the wood and wood products industry. The design, type of construction, and the type of glue used, etc., are the most important things in this joint that determine its final quality. In this research, the effect of cellulose nanofiber and nanoclay in polyvinyl acetate (PVA) glue at levels of 0, 0.4, and 1.5% in finger joints with lengths of two fingers of 5 and 10 mm was investigated by the free vibration in free-free beam method. In joints without nanoparticles, finger joints with a finger length of 10 mm had better acoustic properties than joints with a finger length of 5 mm, except for the acoustic conversion efficiency factor. The results showed that by adding cellulose nanofiber (CNF) and nanoclay in both finger lengths of 5 and 10 mm at both 0.4% and 1.5% levels, the dynamic modulus of elasticity, elastic stiffness, acoustic coefficient, and acoustic conversion efficiency increased significantly, while the damping factor values showed a significant decrease. In general, the effect of CNF on the acoustic properties of both types of joints was better than that of nanoclay.

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.

This study aims to comprehensively examine the influence of three distinct additives, namely carboxymethyl cellulose (CMC), hydroxypropyl methylcellulose (HPMC), and cellulose nanofibers (CNF), on the performance enhancement of corrugated base paper. For this purpose, steam‐exploded rice straw was treated with varying concentrations (2, 4, 6, 8, and 10 wt%) of CMC, HPMC and CNF. Analysis of the rice straw pre and post expansion, as well as the modified corrugated base paper, was conducted using Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TG), tensile performance testing, and scanning electron microscopy (SEM). Results indicated that adding CMC, CNF, and HPMC to corrugated base paper significantly improved bonding between paper layers, particularly at 2 %, 6 %, and 8 % concentrations, respectively. This enhancement notably increased tensile strength and elastic modulus of the corrugated base paper. Tensile performance saw increases of 57.76 %, 59.01 %, and 60.25 %, while elastic modulus showed increments of 52.7 %, 9.4 %, and 136.69 %, respectively. These findings provide valuable insights for the preparation of corrugated base paper and highlight the potential of CMC, HPMC, and CNF in enhancing paper mechanical properties. [ABSTRACT FROM AUTHOR]

Water evaporation‐induced electricity generators (WEIGs) are promising as self‐powered electronic devices, as they can harvest green, small‐grade, and ubiquitous hydrovoltaic energy in ambient environment to electricity. Here, biodegradable wood‐based WEIGs with high performance are reported by removing lignin and hemicellulose from balsa wood (BW) with more exposed cellulose nanofibrils. Delignified BW (DBW) and cellulosic BW (CBW) display significant enhance in open circuit potential (Voc) and short circuit current (Isc) due to increased specific surface area, hydrophilicity, and surface charge density. The electricity‐generating performance of CBW‐based WEIG (CBWG) is not stable due to its structural collapse. DBW‐based WEIG (DBWG) shows a steady electricity output and fast responsivity to ambient environments, such as humidity, temperature, light, and wind. Therefore, DBWGs can be employed as self‐powered environmental sensors. The effects of different kinds of electrolytes with varied concentrations on the performance of DBWG are also studied. The DBWG (40 mm × 40 mm × 2 mm) displays a Voc of 0.77 V and Isc of 148 µA in 1.2 m CaCl2 solution. In this study, all wood‐based sustainable WEIGs with high electricity generating performance are facilely prepared and are promising for remote self‐powered environmental sensors and power sources. [ABSTRACT FROM AUTHOR]

This study introduces the development of a novel bio-nano composite via the dispersion of cellulose nanofibers (CNF) in epoxy. The surface of cellulose nanofibers was functionalized using a two-step chemical treatment to enhance dispersion. The interfacial characteristics of CNF were improved using alcohol/acetone treatments. The modified CNF (M-CNF) demonstrated enhanced compatibility and improved dispersion in the epoxy matrix as evidenced by scanning electron microscopy. Based on the analysis of X-ray diffraction patterns, M-CNF did not disturb the crystalline phases at the interface. The results of mechanical testing showed that M-CNF worked as a reinforcing agent in the bio-nano composite. The flexural modulus increased from 1.4 to 3.7 GPa when M-CNF was introduced. A similar trend was observed for tensile strength and impact resistance. The optimum performance characteristics were observed at M-CNF of 0.6%. At higher dosages, some agglomeration was observed, which weakened the interfacial properties. This study promotes sustainability and resource conservation while offering CNF as a sustainable reinforcing agent to develop bio-nano composites. [ABSTRACT FROM AUTHOR]

CNF-PPy/MXene composite films with excellent electromagnetic interference (EMI) shielding and infrared thermal camouflage performance were fabricated by compounding cellulose nanofiber-polypyrrole (CNF-PPy) and MXene. CNF-PPy was prepared by the modified in-situ polymerization of pyrrole on the surfaces of CNFs and exhibited excellent dispersion stability and storage stability in aqueous phase. CNF-PPy films showed enhanced conductivity (~ 3.91 S/cm) and EMI shielding effectiveness (average ~ 28.1 dB in X-band). The composite films loaded with MXene exhibited even better EMI shielding performance (~ 45.8 dB on average in X-band) and good applicability in other bands (~ 44.7 dB in 26.5–40.0 GHz band). The sample CP3M3 presented excellent infrared thermal camouflage properties on the MXene side (45.0 °C at 100 °C) and exhibited different infrared thermal camouflage properties on the other side (84.4 °C at 100 °C on the CNF-PPy side). Given excellent electrical conductivity, dispersion and storage stability of CNF-PPy, enhanced electromagnetic shielding and adjustable infrared emissivity of CNF-PPy/MXene films, the resulting samples can be chosen according to the scenarios, providing a promising method to ensure the smooth operation of military equipment. [ABSTRACT FROM AUTHOR]

We developed a highly sensitive solid-state sensor for mercury detection by stabilizing red-sub-nanometric fluorescent gold nanoclusters (AuNC, 0.9 ± 0.1 nm diameter) with bovine serum albumin in a matrix composed of cellulose nanofibrils (CNF) (BSA-AuNC/CNF). The main morphological and optical features of the system were investigated via atomic force/transmission electron microscopy and UV-Vis/fluorescence spectroscopy. The hybrid film (off-white and highly transparent) showed strong photoluminescene under UV irradiation. The latter is assigned to the AuNC, which also increase the ductility of the emitting film, which was demonstrated for high sensitivity Hg2+ detection. When used as a sensor system, following AuNC printing on CNF hybrid films, a limit of detection <10 nM was confirmed. What is more, nanocellulose films have a high pore structure and selective separation properties, showcasing a wide range of potential applications in many fields such as water treatment and oil–water separation. [ABSTRACT FROM AUTHOR]

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica 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.)

This research focuses on the application of nanocellulose-stabilized silver nanoparticles (AgNPs) as a colorimetric sensing probe for mercury (II) detection. For this purpose, cellulose nanocrystals (CNCs) and cellulose nanofibers (CNFs) were employed with dual functions: a stabilizing agent and a dispersing matrix. The chemical and structural properties of the samples were analysed by various techniques such as XRD, FTIR, TEM and UV–Vis Spectroscopy. Due to different morphologies and surface functional groups in each type of nanocellulose, their effects on the AgNP formation as well as their response against mercury (II) ions were studied. It was discovered that the AgNPs stabilized by both types of nanocellulose can provide high sensitivity and selectivity towards mercury (II) ions. However, some interference caused by iron (III) ions was observed. This interference could be significantly reduced if the CNFs were employed during the AgNP preparation. Therefore, the advantage of using the CNFs as a stabilizing agent as well as a dispersing matrix will be discussed in detail. Furthermore, the possibility of fabrication into solid-state platforms (nanopapers) and response to mercury (II) ions will be demonstrated. [ABSTRACT FROM AUTHOR]

Porous β-tricalcium phosphate (Ca3(PO4)2; β-TCP) was prepared via freeze-drying and the effects of this process on pore shapes and sizes were investigated. Various samples were prepared by freezing β-TCP slurries above a liquid nitrogen surface at −180 °C with subsequent immersion in liquid nitrogen at −196 °C. These materials were then dried under reduced pressure in a freeze-dryer, after which they were sintered with heating. Compared with conventional heat-based drying, the resulting pores were more spherical, which increased both the mechanical strength and porosity of the β-TCP. These materials had a wide range of pore sizes from 50 to 200 µm, with the mean and median values both approximately 100 µm regardless of the freeze-drying conditions. Mercury porosimetry data showed that the samples contained small, interconnected pores with sizes of 1.24 ± 0.25 µm and macroscopic, interconnected pores of 25.8 ± 4.7 µm in size. The effects of nonionic surfactants having different hydrophilic/lipophilic balance (HLB) values on foaming and pore size were also investigated. Materials made with surfactants having lower HLB values exhibited smaller pores and lower porosity, whereas higher HLB surfactants gave higher porosity and slightly larger macropores. Even so, the pore diameter could not be readily controlled solely by adjusting the HLB value. The findings of this work indicated that high porosity (>75%) and good compressive strength (>2 MPa) can both be obtained in the same porous material and that foaming agents with HLB values between 12.0 and 13.5 were optimal. [ABSTRACT FROM AUTHOR]

Nanocomposite represents the backbone of many industrial fabrication applications and exerts a substantial social impact. Among these composites, metal nanostructures are often employed as the active constituents, thanks to their various chemical and physical properties, which offer the ability to tune the application scenarios in thermal management, energy storage, and biostable materials, respectively. Nanocellulose, as an emerging polymer substrate, possesses unique properties of abundance, mechanical flexibility, environmental friendliness, and biocompatibility. Based on the combination of flexible nanocellulose with specific metal fillers, the essential parameters involving mechanical strength, flexibility, anisotropic thermal resistance, and conductivity can be enhanced. Nowadays, the approach has found extensive applications in thermal management, energy storage, biostable electronic materials, and piezoelectric devices. Therefore, it is essential to thoroughly correlate cellulose nanocomposites' properties with different metallic fillers. This review summarizes the extraction of nanocellulose and preparation of metal modified cellulose nanocomposites, including their wide and particular applications in modern advanced devices. Moreover, we also discuss the challenges in the synthesis, the emerging designs, and unique structures, promising directions for future research. We wish this review can give a valuable overview of the unique combination and inspire the research directions of the multifunctional nanocomposites using proper cellulose and metallic fillers. [ABSTRACT FROM AUTHOR]

Cellulose, being a renewable and abundant biopolymer, has garnered significant attention for its unique properties and potential applications in hybrid materials. Understanding the hierarchical arrangement of cellulose nanofibers is crucial for developing cellulose‐based materials with enhanced mechanical properties. In this study, the use of Scanning Electron Diffraction (SED) is presented to map the nanoscale orientation of cellulose fibers in a bio‐composite material with a preserved wood cell structure. The SED data provides detailed insights into the ordering of cellulose with an extraordinary resolution of ≈15 nm. It enables a quantitative analysis of the fiber orientation over regions as large as entire cells. A highly organized arrangement of cellulose fibers within the secondary cell wall is observed, with a gradient of orientations toward the outer part of the wall. The in‐plane fiber rotation is quantified, revealing a uniform orientation close to the middle lamella. Transversely sectioned material exhibits similar trends, suggesting a layered cell wall structure. Based on the SED data, a 3D model depicting the complex helical alignment of fibers throughout the cell wall is constructed. This study demonstrates the unique opportunities SED provides for characterizing the nanoscale hierarchical arrangement of cellulose nanofibers, empowering further research on a range of hybrid materials. [ABSTRACT FROM AUTHOR]

Spent engine oil is a major source of environmental pollution that affects the aquatic ecosystem and human health. Cellulose nanofibers (CNF) are natural nanomaterials that can be used as additives in spent engine oil to enhance its performance, especially at high temperatures and pressures. Utilizing sulfur-based unbleached rice straw pulping technique, the rice straw was grinded in a solution with 10 % sodium sulfite and 2 % sodium carbonate, that heated to 160 °C for 2 h. This produces unbleached sulfur pulp, which is then analyzed for ash, cellulose, and lignin content. A subsequent bleaching step at 80 °C with a sodium chlorite/acetic acid mix completes the process. This technique was adopted to produce CNF. In this study, preparation and characteriztion of CNF-additives to spent engine oil was performed using different techniquessuch as; IR spectra analysis, kinematic viscosity, and wear scar width. It was also evaluated on the oil adsorption, vibration, and noise reduction properties of the resulted additive oil. The results showed that CNF improved viscosity, lubrication, and anti-wear properties of the oil, and decreased its friction, vibration, and noise. The optimal concentration of CNF was 2.0 wt%, which increased the kinematic viscosity by 14.5 % and reduced the wear scar width by 31 % compared to the spent oil sample. Moreovere, CNF reduced the environmental impact of oil disposal and recycling. Overall, CNF are promising nanofillers for improving the performance of spent engine oil and lowering its environmental impact.

The inherent properties of cellulose nanofibers (CNFs) make them an interesting and sustainable choice for reinforcing polymeric matrices intended for the automotive, electronic, construction, and packaging sectors. Effective recycling and reuse of polyamide 6.6 significantly reduce the environmental impact of automotive components throughout its entire life cycle. Nanocomposites of recycled polyamide 6.6 and CNF and of virgin polyamide 6.6 and CNF were processed through dissolution in a formic acid/water mixture followed by melt extrusion and injection molding. The results show that pure recycled polyamide exhibited a thermal degradation onset temperature 10 °C lower and a 9 % lower crystallinity compared to pure virgin polyamide. The method used for processing the nanocomposites resulted in homogeneous dispersion and good anchoring of CNF in both polymer matrices. The processing method and the presence of CNF reduce the thermal stability by up to 15 °C for recycled polyamide nanocomposites and up to 26 °C for virgin polyamide nanocomposites. The processing method did not significantly impair the elastic modulus and tensile strength of both recycled and virgin polyamides, showing a 3 % and 1 % reduction in tensile strength for recycled and virgin polyamides, respectively. The incorporation of 1 wt% and 2 wt% of CNF in virgin polyamide showed an increase in the elastic modulus of 16 % and 5 %, respectively, and a reduction in ductility. In summary, this work offers an alternative processing pathway for nanocomposites of recycled or virgin polyamide 6.6 with CNF; however, some improvements are still necessary to achieve the reinforcing effect of CNF on the mechanical strength of the matrices.

Abstract In parallel with the development of novel materials, such as cellulose nanofibers (CNFs), their effects on aquatic organisms should be evaluated. In ecotoxicity testing, concentration measurements are important to obtain accurate exposure concentrations; however, few studies have measured the concentration and dispersion state of CNFs in test solutions. Therefore, we evaluated the applicability of enzymatic and phenol–sulfuric acid methods for CNF quantification in ecotoxicity testing. In the enzymatic method, CNF content was determined by quantifying the d-glucose produced from the CNFs using cellulase with a glucose assay kit. Three types of cellulases were purchased, and impurities such as d-glucose were identified and removed. The differences in CNF degradation efficiency among the cellulases were evaluated, and a cellulase suitable for CNF degradation was selected. In the phenol–sulfuric acid method, a microplate-based method was employed to handle a large number of samples. We demonstrated that both the enzymatic and phenol–sulfuric acid methods could quantify CNFs in media for ecotoxicity testing. The enzymatic method was able to measure lower CNF concentrations (~ 1 mg/L) than the phenol–sulfuric acid method (~ 10 mg/L) and had less interference with CNF quantification by algae and non-cellulosic polysaccharides.

Lignocellulosic materials have inherent complexities and natural nanoarchitectures, such as various chemical constituents in wood cell walls, structural factors such as fillers, surface properties, and variations in production. Recently, the development of lignocellulosic filler-reinforced polymer composites has attracted increasing attention due to their potential in various industries, which are recognized for environmental sustainability and impressive mechanical properties. The growing demand for these composites comes with increased complexity regarding their specifications. Conventional trial-and-error methods to achieve desired properties are time-intensive and costly, posing challenges to efficient production. Addressing these issues, our research employs a data-driven approach to streamline the development of lignocellulosic composites. In this study, we developed a machine learning (ML)-assisted prediction model for the impact energy of the lignocellulosic filler-reinforced polypropylene (PP) composites. Firstly, we focused on the influence of natural supramolecular structures in biomass fillers, where the Fourier transform infrared spectra and the specific surface area are used, on the mechanical properties of the PP composites. Subsequently, the effectiveness of the ML model was verified by selecting and preparing promising composites. This model demonstrated sufficient accuracy for predicting the impact energy of the PP composites. In essence, this approach streamlines selecting wood species, saving valuable time.

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In parallel with the development of novel materials, such as cellulose nanofibers (CNFs), their effects on aquatic organisms should be evaluated. In ecotoxicity testing, concentration measurements are important to obtain accurate exposure concentrations; however, few studies have measured the concentration and dispersion state of CNFs in test solutions. Therefore, we evaluated the applicability of enzymatic and phenol–sulfuric acid methods for CNF quantification in ecotoxicity testing. In the enzymatic method, CNF content was determined by quantifying the d-glucose produced from the CNFs using cellulase with a glucose assay kit. Three types of cellulases were purchased, and impurities such as d-glucose were identified and removed. The differences in CNF degradation efficiency among the cellulases were evaluated, and a cellulase suitable for CNF degradation was selected. In the phenol–sulfuric acid method, a microplate-based method was employed to handle a large number of samples. We demonstrated that both the enzymatic and phenol–sulfuric acid methods could quantify CNFs in media for ecotoxicity testing. The enzymatic method was able to measure lower CNF concentrations (~ 1 mg/L) than the phenol–sulfuric acid method (~ 10 mg/L) and had less interference with CNF quantification by algae and non-cellulosic polysaccharides. [ABSTRACT FROM AUTHOR]

[Display omitted] • A time-multiplexed self-erasing nanopaper was tailored for information encryption. • Cellulose nanofibers integrating gold nanoclusters and long afterglow materials. • Array information on nanopaper was written by different ethanol aqueous solutions. • The array iterated variation as solvent volatilization during afterglow time scale. The progressive presentation of multilevel information enhances the security level of information storage and transmission. Here, a time-multiplexed self-erasing nanopaper was developed by integrating cellulose nanofiber (CNF)-stabilized gold nanoclusters and CNF-modified long afterglow materials. The orange fluorescence of gold nanoclusters on nanopaper was regulated by the reversible swelling and shrinking of CNF induced by water solution, while the cyan fluorescence of micron-long afterglow remained stable and acted as the background signal. It was noteworthy that the fluorescence colour and intensity of the nanopaper could be freely adjusted between orange and cyan on the time scale. Therefore, the array information on the nanopaper could be encoded by a water solution, iterated variation as the step-by-step solvent volatilized on the time scale measured by the time of the afterglow duration. This work provides a new approach for constructing time-multiplexed self-erasing nanopaper for confidential information storage and transmission. [ABSTRACT FROM AUTHOR]

Background and Objectives: Fine dust air pollution poses a significant health threat in arid and semi-arid regions worldwide. Inhaling these particles is linked to cardiovascular issues, reduced lung function, skin problems, respiratory irritation, and an increased risk of cancer. Existing respiratory masks often struggle to capture these fine particles (less than 2.5 microns) due to the limitations of conventional filter materials. This study explored enhancing respiratory filter performance by applying a deep-coating method with cellulose nanofibers (CNFs) on a cellulosic substrate. We investigated CNF concentrations of 0.05%, 0.1%, 0.2%, and 0.5%. Coated filters were freeze-dried at -50 °C and 0.04 mbar pressure. These modifications aimed to improve filter absorption capacity, addressing the limitations of conventional filters and offering a novel approach to mitigate health risks from fine dust inhalation. Materials and Methods: Wood cellulose nanofiber gel (WCNFs) was obtained from Nano Novin Polymer Co., Iran. Carboxymethyl cellulose (CMC) and citric acid (CA) were purchased from Dr. Mojallali Co., Iran. The cotton fabric substrate came from Live Co., Iran. Sample characterization employed Fourier-transform infrared spectroscopy (ATR-FTIR), X-ray diffraction (XRD), filter pressure drop measurement, field-emission scanning electron microscopy (FESEM), and a fine particle adsorption test. Results: The FTIR test confirmed the purity of the cellulosic substrate used for CNF coating. XRD analysis revealed the presence of β1-cellulose in the substrate, indicated by distinct peaks at 2θ angles of 15.5°, 16.5°, 22.5°, and 34.5°. This structure facilitated strong bonding between CNFs and the substrate. FESEM imaging confirmed the presence of nanofibers (below 100 nm), enabling the formation of nano- and submicron pores. While increasing CNF concentration generally raised pressure drop, the optimal treatment involved a 5-layer sample with two layers containing 0.5% CNFs. This configuration achieved a remarkable 96.18% absorption efficiency for particles smaller than 2 microns, exceeding the N95 standard set by the Food and Drug Administration. [ABSTRACT FROM AUTHOR]

This work reports the fabrication of a large‐sized hydrogel sheet with enhanced mechanical and adhesive properties. The fabrication involves the introduction of carboxymethyl‐modified cellulose nanofibers (m‐CNFs) and solid silica nanoparticles (SSNs) as physical cross‐linkers into acrylic acid monomer (AA), followed by bar coating and photopolymerization. The addition of the nanomaterials to the monomer solution renders it viscous, enabling the fabrication of A4‐sized hydrogel sheets with uniform thickness and enhanced mechanical and adhesive properties. Interestingly, the combined incorporation of both the nanomaterials generates a synergistic effect to improve the properties much more, which results from the hierarchical rupture of the multiple hydrogen‐bonded interactions among the poly(acrylic acid) (PAA) matrix, m‐CNFs, and SSNs. Under optimal conditions, the hydrogel sheet incorporated with the dual crosslinkers exhibits a sevenfold higher toughness and a sixfold increased peel strength than plain PAA, together with good biocompatibility. Furthermore, when mesoporous silica nanoparticles (MSNs) with active agent loading into their pores are incorporated instead of SSNs, the active agent can be released from the hydrogel sheet in a sustained or temperature‐sensitive manner, indicating that the system is potentially applicable to transdermal drug delivery system with no additional adhesive. [ABSTRACT FROM AUTHOR]

In this study, sulfated cellulose pulps (SCPs), synthesized via environmentally friendly methods by supporting sulfamic acid and urea on wood-derived cellulose pulps (CPs), were used to prepare completely dispersed cellulose nanofibers (CNs). CP is a sustainable natural polymer that is biodegradable, nontoxic, and relatively inexpensive. Additionally, cellulose nanofibers prepared from CPs have attracted attention as promising natural nanofibers with various useful properties. Therefore, sulfation of CP with sulfamic acid and urea was investigated as a method for preparing completely dispersed CNs. The SCPs were synthesized in high yields through the sulfamic acid ≥ urea (molar ratio) reaction system at 393 K for 30 min. The SCPs contained sulfate groups with 0.79–1.33 mmol g−1 at hydroxy groups of C6, and C2 and/or C3 positions of cellulose, maintained long fibers and exhibited a 429–880 degree of polymerization (DP), retaining 60% more DP than the original CP. Some SCPs attained a maximum water retention value of approximately 3000%, suggesting a swollen fiber structure. Completely dispersed sulfated CNs with a fiber diameter of approximately 3–4 nm could be prepared by defibrating these SCPs. The swollen fiber structure observed in the SCPs reduced the defibrated energy and time required to achieve complete dispersion. [ABSTRACT FROM AUTHOR]

Climate change, largely attributable to the extensive use of fossil fuels and deforestation, poses a critical global issue. There is a pressing need for innovative and sustainable solutions. This study highlights a significant advancement in materials science: a biomass-sourced transparent composite developed from cellulose nanofibers (CNFs) and isosorbide polycarbonates (ISB-PC). This green glazing material serves as a potential replacement for heavy, easily shattered glass in the construction and automotive industries, exhibiting remarkable thermal properties, light transmittance, and mechanical resilience. Notably, the thermal dimensional stability and transparency of the composite matches that of conventional glass. An integral accomplishment is the development of a multi-layered sheet with a thickness beyond 350 μm. These sheets achieved a light transmittance of 62.0% and coefficient of thermal expansion below 60 ppm K−1 (30–120 °C). Another distinguishing feature of this composite is its potential for carbon sequestration owing to its non-degradability. This study underscores the composite's potential as an eco-friendly alternative to glass. [ABSTRACT FROM AUTHOR]

Featured Application: Porous material with high sound absorption and thermal insulation properties. The automotive industry needs to improve energy efficiency rapidly to achieve carbon neutrality while creating a safe, secure, and comfortable driving environment for customers. Porous sound-absorbing materials and porous thermal insulators are typically used to satisfy these requirements despite limitations in mass and space. While these porous materials are similar, the microstructures they offer for high performance differ in the size and connectivity of their fluid phases, which enhances the difficulty of achieving excellent sound absorption and thermal insulation in the same material. In this study, a hydrophobic cellulose nanofiber–poly(methylsiloxane) xerogel composite was developed using computational microstructure modeling. This porous material has high porosity and excellent thermal insulation and sound absorption properties. [ABSTRACT FROM AUTHOR]

Membranes find applications across a wide spectrum of industries, including water treatment, energy production, and biomedicine. In this study, nonwoven membranes were fabricated using cellulose acetate (CA) as the primary component, with varying percentages of cellulose nanofibers (CNFs) embedded as reinforcement. These CNFs were prepared through an oxalic acid pretreatment (Oxalic-CNFs). Their incorporation into electrospun membranes represents an innovative approach, enhancing their mechanical properties for applications subjected to high loads and improving its functionalization capabilities. The impact of Oxalic-CNFs on membrane properties was investigated at nanofiber loadings ranging from 0 to 18 wt%. Membranes produced with 6 wt% Oxalic-CNF exhibited the superior physical and mechanical properties. This improvement can be attributed to the formation of threads with higher intrinsic strength, a reduction in pore size, and an increase in density. When higher percentages of CNFs were added, the membranes were not properly formed, because filaments were not continuous and the needle became clogged. The substructure of the membrane proved to be a critical factor for mechanical properties, with remarkable increases in tensile strength and elastic modulus (around 300%) when comparing 4–6 wt% Oxalic-CNF-loaded membranes to CA membranes. [ABSTRACT FROM AUTHOR]

Bio-based and biodegradable materials have received special interests in recent years as a replacement for petroleum-based plastics. Poly(vinyl alcohol) (PVA), cellulose nanofiber (CNF), and 2,5-furandicarboxylic acid (FDCA) are typical examples among these environmentally friendly molecules. In this study, we investigated the synergistic effects of CNF reinforcement and crosslinking with FDCA on the properties of PVA. The composite films were prepared via a straightforward mechanical-dispersion method, wherein CNF was incorporated into a PVA solution and subsequently crosslinked with FDCA. Comprehensive characterizations, including Attenuated Total Reflection-Fourier Transform Infrared Spectroscopy (ATR-IR), X-ray diffraction (XRD), Thermal Gravimetric Analysis/Differential Thermal Gravimetric Analysis (TGA/DTGA), Differential Scanning Calorimetry (DSC), tensile testing, and morphological studies, were performed to assess the impact of these modifications. Our findings revealed significant enhancements in the mechanical and thermal properties of the composites. Notably, the tensile strength of the PVA-c-FDCA/CNF composite with 2% CNF reached 37.08 MPa, representing a twofold increase compared to both crosslinked PVA (16.84 MPa) and unmodified PVA (14.57 MPa). TGA/DTGA analysis demonstrated improved thermal stability, with the degradation temperature reaching 371°C, compared to the 298°C observed for PVA. DSC and XRD results indicated a reduction in PVA crystallinity after crosslinking and blending with CNF. Scanning electron microscopy (SEM) images showed good compatibility between PVA and CNF. This study underscores the potential of CNF reinforcement and FDCA crosslinking as a viable strategy to enhance the mechanical properties of PVA-based materials. [ABSTRACT FROM AUTHOR]

Carbon sphere@layered double hydroxides filled cellulose nanofibers (ACS@LDHs/CNF) aerogel was successfully synthesized. The removal rate of Cr(VI) using ACS@LDHs/CNFs aerogel at a solid-liquid ratio of 1 g/L was 89.4%, which was higher compared to the removal rate of 65.2% using LDHs alone. The adsorption capacity of ACS@LDHs/CNFs for Cr(VI) was determined to be 44.9 mg/g. The adsorption kinetics followed the pseudo-second-order kinetic equation, and the isotherm data showed good agreement with the Langmuir model. The adsorption mechanism of Cr(VI) onto ACS@LDHs/CNFs aerogel was also investigated. Additionally, the ACS@LDHs/CNFs aerogel demonstrated consistent high adsorption efficiency over 4 consecutive cycles of adsorption-regeneration. [ABSTRACT FROM AUTHOR]

This paper prepared the composite aerogel by adding graphene oxide (GO) and polypyrrole (PPy) to the cellulose nanofiber suspension. Then GO was reduced to RGO (reduced graphene oxide) with reducing agent, and CNFs/RGO/PPy composite aerogel with excellent conductivity was prepared. Scanning electron microscope (SEM) was adopted to analyze the structure and morphology of CNFs/RGO/PPy aerogel. Cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS) were employed to analyze its electrochemical properties. The results showed that the best structure and electrochemical effect could be obtained when the ratio of CNFs/RGO/PPy was 6:2:3. At the current density of 0.25 mA cm−2, CNFs/RGO/PPy composite aerogel had higher electrochemical performance, and the specific capacitance was 330 F g−1. As an energy storage material, the composite has excellent potential in electrode materials. [ABSTRACT FROM AUTHOR]

Fluorinated octyl silane-modified cellulose nanofibers (FOTS-CNF) were successfully prepared from 2,2,6,6-tetramethylpiperidine-1-oxyl-oxidized CNFs (TOCNFs) derived from agricultural waste hop stems. The surface structures of the FOTS-modified CNFs were site-specifically investigated by 13C/19F/29Si solid-state nuclear magnetic resonance and Fourier-transform infrared spectroscopy. The spectroscopic results indicated that siloxane layers with fluorinated octyl chains extensively covered on the hydrophilic surface of the TOCNFs. This hydrophobic surface coating exhibited the highest water contact angle of 126.9°. [ABSTRACT FROM AUTHOR]

The primary objective of the study was to develop a method for enhancing the oil adsorption capacity of cellulose nanofibers (CNFs) by modifying their surface. To achieve this goal, aerogels were first dried in a freeze dryer, followed by surface hydrophobization of CNFs using hexadecyltrimethoxysilane (HDTMS) as the modifier. The optimal concentration of the HDTMS for enhancing the nanofiber's surface was determined by testing different concentrations ranging from 0 to 3 mL. The efficacy of the modifier was confirmed by FTIR, which showed the presence of functional groups and hydrogen bonding between CNFs and HDTMS. BET analysis revealed that high concentrations of HDTMS modifier increased the density and reduced the porosity of the aerogels. Moreover, the high concentration of the modifier improved the pressure resistance of the aerogels, with the highest pressure resistance observed for the sample modified with 2 mL of HDTMS. The oil adsorption capacity of the modified samples was also evaluated, and it was found that the highest oil adsorption capacity was observed for the adsorbent with 0.5 mL of the modifier. Conversely, the lowest adsorption rate was observed for the adsorbent with 3 mL of the modifier. Interestingly, it was observed that higher-viscosity oil was absorbed less effectively than lower-viscosity oil. SEM micrographs showed that increasing the amount of HDTMS modifier in the samples resulted in smaller existing pores, thicker pore walls, and a transition from hydrophilic to hydrophobic aerogels. Overall, the results suggest that the optimal concentration of HDTMS for enhancing the surface of the nanofibers is 2 mL, as this concentration provides the highest pressure resistance while still maintaining good oil adsorption capacity. [ABSTRACT FROM AUTHOR]

This paper reports a high-performance humidity sensor made using a novel cellulose nanofiber (CNF)–silver nanoparticle (AgNP) sensing material. The interdigital electrode pattern was printed via reverse-offset printing using Ag nano-ink, and the sensing layer on the printed interdigitated electrode (IDE) was formed by depositing the CNF-AgNP composite via inkjet printing. The structure and morphology of the CNF-AgNP layer are characterized using ultraviolet–visible spectroscopy, an X-ray diffractometer, field emission scanning electron microscopy, energy-dispersive X-ray analysis, and transmission electron microscopy. The humidity-sensing performance of the prepared sensors is evaluated by measuring the impedance changes under the relative humidity variation between 10 and 90% relative humidity. The CNF-AgNP sensor exhibited very sensitive and fast humidity-sensing responses compared to the CNF sensor. The electrode distance effect and the response and recovery times are investigated. The enhanced humidity-sensing performance is reflected in the increased conductivity of the Ag nanoparticles and the adsorption of free water molecules associated with the porous characteristics of the CNF layer. The CNF-AgNP composite enables the development of highly sensitive, fast-responding, reproducible, flexible, and inexpensive humidity sensors. [ABSTRACT FROM AUTHOR]

Nanocellulose-based materials have attracted the scientific community's attention due to their abundance in nature, biocompatibility, high surface area, high strength, low toxicity, and low production cost. These environmental-friendly materials have potential applications for developing hydrogels, aerogels, electrodes, adsorbents, packaging films, membranes, nano papers, filters, biomaterials for biomedical, and composites. The present work monitors scientific reports and patent databases of recent achievements on nanocellulose-based composites used as sorbent materials. Most of the pieces found used non-wood, wood, agro-waste, and microorganism sources to obtain nanocellulose. The search identifies most applications were for removing dyes, heavy metals, odor, organic particles from water, and absorption of hemoglobin and immunoglobulin. In addition, it was possible to confirm fifty patent applications on nanocellulose-based sorbent composites. This review was relevant to evaluate the potentiality of applications about nanocellulose as a based sorbent in composites, giving a systematic overview of what has been made and what could be the new potential sources and applications that would be used in future works of this material. [ABSTRACT FROM AUTHOR]