Effect Of Cellulose Nanofibers Research Articles

Cellulose reinforcement of plant-based protein hydrogels: Effects of cellulose nanofibers and nanocrystals on physicochemical properties

This study explored the impact of cellulose-derived fillers, cellulose nanofibers (CNFs) and cellulose nanocrystals (CNCs), on the microstructure and texture of potato protein hydrogels (20 wt% protein). Particle size analysis, surface charge analysis, and molecular docking simulations suggested that the cellulose nanofibers and nanocrystals acted as inactive fillers within the potato protein matrix. Texture profile analysis showed that incorporation of small amounts of CNFs (<1%) increased the gel strength (by up to 69%), but the addition of larger amounts decreased it, which was attributed to disruption of the protein network by aggregated nanofibers at higher concentrations. The incorporation of CNCs had a much smaller effect on the gel strength of the potato protein hydrogels, only increasing it by up to 15% at 2% CNC. Shearing the cellulose-reinforced hydrogels in a shear rheometer had little impact on their gel strength at lower filler concentrations (<2 wt%) but increased it at higher concentrations. Microscopy analysis showed that the cellulose fibers could be aligned at sufficiently high shearing rates, leading to a fibrous microstructure. This study provides valuable insights into the optimization of the properties of cellulose fillers for application in plant protein hydrogels. In particular, it suggests that they may be utilized in plant-based meat analogs to enhance their textural attributes and optimize their appearance.

Effect of cellulose nanofibers and recycled glass powder on the geotechnical and microstructural parameters of dispersive soil

Effect of cellulose nanofibers and recycled glass powder on the geotechnical and microstructural parameters of dispersive soil

Preparation of High-Toughness Cellulose Nanofiber/Polylactic Acid Bionanocomposite Films via Gel-like Cellulose Nanofibers.

This study demonstrates a procedure for preparing gel-like cellulose nanofibers (CNFs) in polyethylene glycol (PEG) to toughen polylactic acid (PLA) nanocomposite films. A well-dispersed solution of CNFs in ethanol was produced from microcrystalline cellulose by using a high-pressure microfluidizer. The fiber diameter of CNFs was found to be in the range of 80-100 nm. Ethanol was replaced by PEG using a rotary evaporator to obtain gel-like CNFs/PEG. PLA/PEG/CNF films were prepared using the solvent casting method, with the CNF content varying from 0.15 to 5 phr. The effect of CNFs on the mechanical, morphological, and thermal properties of PLA nanocomposite films was investigated. The results demonstrate that the addition of CNFs improved Young's modulus and toughness of PLA/PEG films. In contrast, a slight decrease in mechanical properties was observed when the content of CNFs reached 0.83 phr. Considère's constructions are used to explain the neck phenomena and cold drawing of nanocomposite films. The crystallization and thermal stability of PLA nanocomposite films were enhanced, with a slight decrease in cold-crystalline temperature (T cc) and an increase in decomposition temperature (T d).

Effects of cellulose nanofibers on soil water retention and aggregate stability

Innovative solutions that address global challenges such as water scarcity and soil erosion are critical for maintaining sustainable agriculture. Due to their water-absorbing and soil-binding properties, cellulose nanofibers (CNF) can be applied to soil to enhance soil water retention and aggregate stability. In this study, we analyzed the effects of the drying temperature, dosage, irrigation water quality, and soil type on the efficacy of CNFs. Our results revealed that CNF dried at 5°C is more effective at absorbing water than others, and adding 1% CNF enhanced soil water content up to 98%. The CNF samples absorbed water due to their hydrophilic molecular groups and morphological structure, as confirmed by Fourier-transform infrared spectroscopy and scanning electron microscopy. CNF addition increased the soil volumetric water content and prolonged water retention by 22 days in the paddy soil samples, highlighting its potential for drought-prone areas. Furthermore, irrigation water quality, such as pH and cation values, influenced the interactions between CNF and water molecules, suggesting adjustments to the water retention curve. In its hydrated state, CNF promotes colloid flocculation and binds to soil particles, thereby strengthening the bonds crucial for aggregate formation and stability. CNF enhanced macro-aggregate formation by up to 48% and 59% in the masa and paddy soil samples, respectively. Our study emphasizes the potential of CNF for water conservation, soil health, and overall agricultural sustainability.

Potential use of nanofibrillated cellulose-loaded cationic starch solutions as coating formulation for recycled fluting papers

Effects of cellulose nanofibers (CNF) and cationic starch (CS) were evaluated as coating components relative to the physical and mechanical properties of fluting papersheets fabricated from recycled corrugated cardboard fibers. Fabricated fluting papers were subjected to size press applications by three different coating blends. Coating suspensions were prepared at various concentrations of CNF (0.5%, 1%, 2%, 3%, and 4%) and 4 wt% CS, and the same amounts of CS/CNF. The paper sheets were fabricated using size press machine as three-time repetitive applications, followed by one-time drying section, and compared to uncoated, CS-coated, and CNF-coated papers. The application of CNF suspensions increased tensile indices up to 11.7%. Moreover, CS/CNF suspensions resulted in a 67.2% increase in tensile index values. The coating of CS/CNF suspensions increased the burst index values by 163% at the CS+1%CNF concentration when compared to the control pulp. Surface application of prepared suspensions reduced the porosity of the samples under all conditions. The highest reduction in the air permeability was observed in the CS+4%CNF-coated samples as 91.5%. It can be concluded that the superficial applications of CNF on the physical and mechanical properties of recycled fluting paper was more effective in the presence of CS.

Synergistic Toughening of Epoxy Composite with Cellulose Nanofiber and Continuous Pineapple Leaf Fiber as Sustainable Reinforcements.

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

나노셀룰로오스 분말 개발과 폴리젖산 내 핵제 적용 연구

Because of the global pollution caused by plastic disposal, demand for eco-friendly transformation in the packaging industry is increased. As part of that, the utilization of polylactic acid (PLA) as a food packaging material is increased. However, it is necessary to improve the crystallinity of PLA by adding nucleating agents or to improve the modulus by adding fillers because of the excessive brittleness of the PLA matrix. Thus, the cellulose nanofiber (CNF) was fabricated and dried to obtain a powder form and applied to the CNF/PLA nanocomposite. The effect of CNF on the morphological, thermal, rheological, and dynamic mechanical properties of the composite was analyzed. We can confirm the impregnated CNF particle in the PLA matrix through the field emission scanning electron microscope (FESEM). Differential scanning calorimetry (DSC) analysis showed that the crystallinity of not annealed CNF/PLA nanocomposite was increased approximately 2 and 4 times in the 1st and 2nd cycle, respectively, with the shift to lower temperature of cold crystallization temperature (Tcc) in the 2nd cycle. Moreover, the crystallinity of annealed CNF/PLA nanocomposite increased by 13.4%, and shifted Tcc was confirmed.

Polypropylene‐based nanocomposite with improved mechanical properties: Effect of cellulose nanofiber and polyrotaxane with partial miscibility

AbstractThe mechanical properties and miscibility of polymer‐based composites containing cellulose nanofiber (CNF) and polyrotaxane (p‐rtx) as organic fillers were studied in detail. CNF and p‐rtx were introduced as powders into a polypropylene (PP) matrix, and composites were prepared using a simple melt‐compounding method. The best mechanical properties were achieved when CNF and p‐rtx were loaded at a concentration of 0.6 wt%. The Young's modulus of the composite increased by 760 MPa compared with that of the PP matrix. In addition, the presence of mica in the composite promoted the epitaxial growth of PP along the (1 3 0) plane. The various shifts in the melting/crystallization temperatures of the composites prepared at different CNF:p‐rtx ratios confirmed the partial miscibility between the fillers and the matrix. The enhancement in the mechanical properties of the composite is believed to be due to the miscibility of the surfaces of aggregates of the organic fillers with PP and the uniform dispersion of the organic fillers in the matrix.

Effect of Cellulose Nano Fiber on the Physical and Printing Properties of Coated Paper

Cellulose nanofiber is a material that can be applied in various fields through sustainable supply. The applications of cellulose nanofiber to paper is limited, but it is applied to various fields. Paper requires a coating process to improve surface properties, improve printability, and impart new functions such as barrier properties. Petrochemical-based coating materials can be replaced with cellulose nanofibers. Cellulose nanofibers were prepared using TEMPO oxidized pulp as a raw material using a high-pressure homogenizer in order to understand the physical properties of the cellulose nanofibers coated paper. Cellulose nanofibers improved physical properties such as tensile strength and printing characteristics of unsized paper compared to sized paper.

Effects of cellulose nanofibers on flexural behavior of carbon-fiber-reinforced polymer composites with delamination

Abstract Understanding the influence of delamination defects on the damage evolution behavior of carbon-fiber-reinforced polymers (CFRPs) is crucial to improve their engineering applications. This study examined the flexural damage behaviors of CFRP composites by using a combination of acoustic emission (AE) and X-ray micro-computed tomography (micro-CT). Four specimens with different delamination defects and 0.1 wt% cellulose nanofibers (CNFs) were subjected to three-point bending tests. AE was employed to monitor the loading process, and then, micro-CT was utilized to detect the internal damage. The results showed that for the specimens with preset delamination defects near the surface, CNF-reinforced specimen exhibited no obvious enhancement effect on bending strength, and its cumulative acoustic energy decreased by 28% compared with that of CFRP specimens. For the specimen with preset delamination damage in the middle position, CNFs had an obvious enhancement effect on mechanical behavior, and the cumulative acoustic energy decreased by 43%. No obvious kink band was observed in the CNF-reinforced specimens, and during crack propagation, causing cracking and delamination damage was difficult. The results of micro-CT are consistent with those of AE. The results combined the combination of AE and micro-CT reflect the superiority of the hybrid detection system.

Effect of cellulose nanofibers on the fracture toughness mode II of glass fiber/epoxy composite laminates

Cellulose nanofibers (CNFs) were used to improve the fracture toughness of glass fiber reinforced epoxy composites (GFRPs). Different CNF suspensions were prepared and sprayed onto the surface of woven glass fiber laminates. The vacuum resin transfer molding (VaRTM) process was used to manufacture the GFRP composites. End notch flexure tests were conducted to evaluate the effect of CNFs on the critical energy release rate in mode II fracture toughness GIIC. The results revealed that 0.05 wt% was the optimum concentration. The interlaminar fracture toughness GIIC was improved by 28% with the addition of 0.05 wt% of CNFs to GF/epoxy composites. Whereas 0.1 wt% of CNFs resulted in decreasing GIIC due to the uncomplete impregnation of GF with epoxy resin caused by the thicker CNF layer at the interfacial laminates. The toughening mechanisms were investigated using a field-emission electron microscope. Large epoxy deformations and shear hackles were predominant for improving the interlaminar fracture toughness of GFRP composites.

Effect of Cellulose Nanofibers' Structure and Incorporation Route in Waterborne Polyurethane-Urea Based Nanocomposite Inks.

In order to continue the development of inks valid for cold extrusion 3D printing, waterborne, polyurethane-urea (WBPUU) based inks with cellulose nanofibers (CNF), as a rheological modulator, were prepared by two incorporation methods, ex situ and in situ, in which the CNF were added after and during the synthesis process, respectively. Moreover, in order to improve the affinity of the reinforcement with the matrix, modified CNF was also employed. In the ex situ preparation, interactions between CNFs and water prevail over interactions between CNFs and WBPUU nanoparticles, resulting in strong gel-like structures. On the other hand, in situ addition allows the proximity of WBPUU particles and CNF, favoring interactions between both components and allowing the formation of chemical bonds. The fewer amount of CNF/water interactions present in the in situ formulations translates into weaker gel-like structures, with poorer rheological behavior for inks for 3D printing. Stronger gel-like behavior translated into 3D-printed parts with higher precision. However, the direct interactions present between the cellulose and the polyurethane-urea molecules in the in situ preparations, and more so in materials reinforced with carboxylated CNF, result in stronger mechanical properties of the final 3D parts.

Cellulose nanofibers/polyvinyl alcohol blends as an efficient coating to improve the hydrophobic and oleophobic properties of paper

The effect of cellulose nanofibers (CNFs)/polyvinyl alcohol (PVA) coating on the hydrophobic, oleophobic, and strength properties of paper were investigated. The results showed that the size of bamboo fibers (BFs) decreased significantly and the crystallinity increased significantly after biological enzyme treatment. The average length of CNFs obtained by high pressure homogenization was 2.4 µm, the diameter was 28.7 nm, and the crystallinity was 63.63%. When the coating weight of PVA/CNF was 2.0 g/m2 and the CNF dosage was increased from 0.0% to 3.0%, the paper grease resistance grade was increased from 7 to 9, the Cobb value was decreased from 22.68 ± 0.29 g/m2 to 18.37 ± 0.63 g/m2, the contact angle was increased from 67.82° to 93.56°, and the longitudinal and transverse tensile index were increased from 67.72 ± 0.21 N m/g and 37.63 ± 0.25 N m/g to 68.61 ± 0.55 N m/g and 40.71 ± 0.78 N m/g, respectively. When the CNF dosage was 3.0% and the coating weight of PVA/CNF was 4.0 g/m2, the grease resistance grade of the paper was 12, the Cobb value was 21.80 ± 0.39 g/m2, and the longitudinal and transverse tensile indices were 72.11 ± 0.43 N m/g and 42.58 ± 0.48 N m/g, respectively. In summary, the increase of CNFs can effectively improve the lipophobicity, hydrophobicity and tensile strength of the PVA coated paper.

The Effect of Cellulose Nanofibers on Paper Documents Containing Starch and Gelatine Sizing

AbstractThis study aimed to evaluate cellulose nanofibers and their effects on starch and gelatine as the most common surface sizing substances used in historical paper documents. In this study, cellulose nanofibers with a concentration of 1% by weight were prepared as a suspension with ethanol and used for the treatment of unsized samples and samples containing starch and gelatine sizing. The results showed that the application of cellulose nanofiber treatment increased the pH of unsized samples and samples containing starch sizing. After aging, there was a slight decrease in the pH of the samples. Cellulose nanofiber treatment increased the tensile strength of the samples. After accelerated aging, the tensile strength of samples containing starch and gelatine sizing and treated samples increased compared to untreated samples. Samples containing gelatine sizing and samples containing treated starch sizing showed the least amount of colour changes (∆E), respectively, and had the best colorimetry results. The results of the contact angle test of the samples before and after aging showed that cellulose nanofiber treatment did not increase the resistance of the paper to wetting and did not prevent the paper surface from getting wet.

Effect of cellulose nanofibers on polyhydroxybutyrate electrospun scaffold for bone tissue engineering applications

The choice of materials and preparation methods are the most important factors affecting the final characteristics of the scaffolds. In this study, cellulose nanofibers (CNFs) as a nano-additive reinforcer were selected to prepare a polyhydroxybutyrate (PHB) based nanocomposite mat. The PHB/CNF (PC) scaffold properties, created via the electrospinning method, were investigated and compared with pure PHB. The obtained results, in addition to a slight increment of crystallinity (from ≃46 to 53 %), showed better water contact angle (from ≃120 to 96°), appropriate degradation rate (up to ≃25 % weight loss in two months), prominent biomineralization (Ca/P ratio about 1.50), and ≃89 % increment in toughness factor of PC compare to the neat PHB. Moreover, the surface roughness as an affecting parameter on cell behavior was also increased up to ≃43 % in the presence of CNFs. Eventually, not only the MTT assay revealed better human osteoblast MG63 cell viability on PC samples, but also DAPI staining and SEM results confirmed the more plausible cell spreading in the presence of cellulose nano-additive. These improvements, along with the appropriate results of ALP and Alizarin red, authenticate that the newly PC nanocomposite composition has the required efficiency in the field of bone tissue engineering.

The Effect of Cellulose Nanofibers on the Manufacturing of Mini-Tablets by Direct Powder Compression.

Mini-tablets (MTs) contain a small amount of active pharmaceutical ingredients in one small tablet. MTs are advantageous because they can be fine-tuned according to the age and weight of pediatric patients and they are easy for children and the elderly to swallow. However, there are manufacturing concerns such as the difficulty in achieving both hardness and disintegration of a small tablet and it is difficult to keep the tablet weight and drug content consistent in MTs because the mold used for its production is special. In this study, we aimed to determine if an additive such as cellulose nanofibers (CNF), which has been studied in various fields in recent years, could be used to manufacture MTs without difficulties. In this study, an MT was manufactured using a rotary tableting press with a compression force of 2, 5, and 8 kN, and the weight variation, drug content variation, tensile strength, friability, disintegration time, and drug dissolution were evaluated. Of note, the tensile strength of MTs produced with a compression force of ≥5 kN was ≥1.3 MPa, which was comparable to that of an ordinary tablet with an 8 mm diameter and a hardness of ≥30 N. The disintegration time of the MT which was 20-30% CNF was ≤30 s at any compression force. MTs with CNF showed similar disintegration to MTs with other common disintegrants. Therefore, we found that CNF is a functional additive capable of manufacturing MTs by direct powder compression which has both strength and disintegration.

Structural, rheological, and mechanical properties of polyvinyl alcohol composites reinforced with cellulose nanofiber treated by ultrahigh-pressure homogenizer

Cellulose nanofibers (CNF) were prepared by nanoisolation using a newly developed ultrahigh-pressure homogenizer (UHPH). The CNF was treated by UHPH with 0, 10, and 20 passes. The effect of UHPH on defibrillation of the CNF and its structure was investigated. The UHPH-treated CNF reinforced poly(vinyl alcohol) (PVA) composite was fabricated by solvent casting. The effect of CNF on morphology, high-order structure, rheological property, and mechanical performance of PVA/CNF composites was investigated. Structural analyses revealed that fiber diameters and fiber distributions of the CNF decreased, and the relative crystallinity increased with an increase in the UHPH passes. The mechanical treatment by UHPH promoted CNF fiber dissociation without interfering with the CNF crystal structure. High crystallinity and interaction of the hydrogen bonding of the defibrillated, treated CNF significantly enhanced the mechanical performance of the PVA/CNF composites. The UHPH treatment presented defibrillated CNF with high crystallinity, which was developed for the high-potential cellulose nanofiber in fiber-reinforced composite materials.

High-performance medical-grade resin radically reinforced with cellulose nanofibers for 3D printing

The effect of Cellulose NanoFiber (CNF) addition to a medical-grade resin in Stereolithography (SLA) Additive Manufacturing (AM) technology is reported, aiming to elaborate an easily processable, highly stiff bio-compound. CNFs were shear stir blended at various weight ratios with liquid resin. The fabricated nanocomposite materials were introduced in an SLA 3D printer for specimens manufacturing. The mechanical performance was studied according to international standards. Charpy Toughness and Vickers microhardness were calculated for all tested materials. A microscopic and surface analysis was conducted on fractured tensile specimens by Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM), respectively. The thermal and thermomechanical properties were investigated by Thermogravimetric Analysis (TGA), Differential Calorimetry (DSC), and Dynamic Mechanical Analysis (DMA). Significant reinforcement of the medical-grade nanocomposites is reported, with the highest values calculated to be at 1.0 wt% concentration (more than 100% at the tensile strength), while brittleness and rigidity were increased.

Effect of cellulose nanofiber and cellulose nanocrystals reinforcement on the strength and stiffness of PVAc bonded joints

Cellulose nanofiber (CNF) and cellulose nanocrystals (CNC) are strong bio-based materials and have great potential in a reinforcement of the polymeric matrix. This study presents the effect of nanocellulose (CNF and CNC) reinforcement of polyvinyl acetate (PVAc) adhesive. Adhesive formulations with three different concentrations (0.5%, 1%, and 2% w/w) of nanocellulose were prepared by dispersing them in water and mixing the suspension with PVAc adhesive; the other percentages are omitted due to obvious adverse effect. The reinforced adhesive was then used to glue spruce (Picea abies L) and beech (Fagus sylvatica) wood joints to determine joint stiffness and shear strength under static load. Samples were tested at 12% moisture content and after cyclic moisture exposure. Bond line morphology was studied by SEM. FTIR analysis was performed to see the molecular interaction between nanocellulose and PVAc. The addition of nanocellulose to PVAc adhesive significantly improved the elastic stiffness and shear strength of the joints. Optimum elastic stiffness and shear strength values were achieved with a 1% addition of nanocellulose. The general trends are found to be valid for various kind of CNF and CNC.

Cellulose Nanofibers Extracted From Natural Wood Improve the Postharvest Appearance Quality of Apples.

To prolong the shelf life of perishable food with a simple and environmentally friendly postharvest preservation technology is one of the global concerns. This study aimed to explore the application value of biological macromolecule natural cellulose nanofibers (CNFs) in extending the postharvest fruit shelf life. In this study, 0.5% (wt%) CNFs were prepared from natural wood and coated on the surface of early-ripening apple fruits. After 10 days of storage at room temperature, the results revealed that the shelf life of apple fruits with CNF coating was significantly prolonged, and the fruit appearance quality improved. The invisible network structure of CNFs in the fruit epidermis was observed under an atomic force microscope (AFM). The gas chromatography and mass spectrometry (GC-MS) analysis showed that CNFs significantly promoted the formation of epidermal wax, especially fatty alcohols, during storage. In addition, the CNFs remarkably promoted the upregulation of genes related to the synthesis of cuticular wax of apple. In conclusion, this study provides an environmentally sustainable nanomaterial for post-harvest preservation of horticultural products, and also provides a new insight into the effect of CNFs on postharvest storage of apple fruits.