Addition Of Cellulose Nanofibers Research Articles

Synergistic effect by release of corrosion inhibitors via cellulose nanofibers in self-healing polymer coatings to prevent corrosion of carbon steel

To inhibit the corrosion of carbon steel, epoxy polymer coatings were developed using cellulose nanofibers (CNF) and the corrosion inhibitors sodium nitrate (SN) and sodium oleate (SO). The synergistic effects of SN and SO were confirmed by measuring the polarization curves of bare carbon steel in a corrosive solution, which demonstrated the effectiveness of a first action by SN being followed by a second action by SO. In order to control the release rates for the corrosion inhibitors from polymer coatings, the addition of CNF in the polymer was effective. The optimum combination of SN, SO and CNF in the polymer coatings was 8% of SN in the first layer, then 8 and 0.5% of SO and CNF, respectively, in the second layer, which resulted in excellent self-healing properties. The controlled release for the synergistic effect of the corrosion inhibitors allowed them to generate a healing film on the damaged portions of carbon steel

Effect of Medium-Chain-Length Alkyl Silane Modified Nanocellulose in Poly(3-hydroxybutyrate) Nanocomposites

Poly (3-hydroxybutyrate) (PHB) is a valuable biopolymer that is produced in industrial quantity but is not widely used in applications due to some drawbacks. The addition of cellulose nanofibers (CNF) as a biofiller in PHB/CNF nanocomposites may improve PHB properties and enlarge its application field. In this work, n-octyltriethoxy silane (OTES), a medium-chain-length alkyl silane, was used to surface chemically modify the CNF (CNF_OTES) to enhance their hydrophobicity and improve their compatibility with PHB. The surface functionalization of CNF and nanodimension were emphasized by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, thermogravimetric analysis, atomic force microscopy, dynamic light scattering, and water contact angle (CA). Surface modification of CNF with OTES led to an increase in thermal stability by 25 °C and more than the doubling of CA. As a result of the higher surface hydrophobicity, the CNF_OTES were more homogeneously dispersed in PHB than unmodified CNF, leading to a PHB nanocomposite with better thermal and mechanical properties. Thus, an increase by 122% of the storage modulus at 25 °C, a slight increase in crystallinity, a better melting processability, and good thermal stability were obtained after reinforcing PHB with CNF_OTES, paving the way for increasing PHB applicability.

Study on the Effect of Jute CNFs Addition on the Water Absorption and Mechanical Properties of Geopolymer Concrete

This study investigates the influence of thermoplastic polyurethane (TPU) reinforced with jute cellulose nanofibers (CNFs) on the water absorption and mechanical properties of geopolymer concrete. The integration of TPU/jute CNF nanocomposites into geopolymer concrete is explored as a strategy to enhance both its durability and mechanical performance. Geopolymer concrete, a sustainable alternative to traditional Portland cement concrete, is known for its low carbon footprint, but it suffers from high brittleness and water absorption. The water absorption behavior of the modified concrete was assessed, revealing a significant reduction in water uptake due to the hydrophobic nature of TPU and the reinforcing effect of jute CNFs. Additionally, the mechanical properties, including compressive and flexural strengths, were evaluated to understand the impact of the nanocomposites on the structural integrity of the concrete. The addition of TPU/jute CNFs notably enhanced the splitting tensile strength (63.5%), compressive strength (59%), and water absorption (0.59%) of the composite, indicating a promising route for developing high-performance construction materials. The integration of 6 wt% of TPU/jute CNF nanocomposites was found to be optimal, resulting in a uniform matrix, reduced micro-cracks, and improved compressive strength due to enhanced adhesion between the nanocomposites and the geopolymer matrix. Furthermore, a curing temperature of 100 °C was identified as ideal, minimizing unreacted fly ash and enhancing adhesion strength, while higher temperatures (140 °C) led to material deterioration due to rapid water loss. The findings demonstrate that the addition of TPU/jute CNF nanocomposites not only improves resistance to water penetration but also enhances overall mechanical performance. This supports the development of more sustainable and resilient construction materials, contributing to global efforts to reduce the environmental impact of the construction industry. Future research should focus on the long-term durability of these composites under various environmental conditions to validate their effectiveness in real-world applications.

Slip-casting of coarse-grained alumina assisted by cellulose nanofibers addition

Slip-casting of coarse-grained alumina assisted by cellulose nanofibers addition

Polyacrylamide/Cellulose Nanofibers Composite As Quasi Solid Electrolyte for Rechargeable Zinc-Ion-Battery

This research aims to optimize the cellulose nanofiber content in polyacrylamide (PAM) using as quasi-solid electrolyte composites for zinc-ion batteries (ZIBs). The cellulose nanofibers (CNFs) derived from hemp were prepared via alkaline treatment and bleaching process, followed by mechanical defibrillation. The chemical functional group analysis confirmed the successful extraction of lignin and cellulose from hemp fiber. The improved thermal stability of cellulose nanofibers indicated the success of the chemical treatment in removing non-cellulosic components. Furthermore, quasi-solid electrolyte composites of PAM / CNFs at 0.25, 0.5, 0.75, and 1 wt.% of cellulose nanofibers were prepared. At 1 wt.% CNFs addition, PAM / CNFs composites showed the highest values for electrolyte uptake, and electrochemical impedance spectroscopy with the highest ion conductivity of 59.6 mS cm-1. For the plating/stripping testing with symmetrical zinc cell, PAM / CNFs at 1.0 %wt CNF also demonstrated the lowest overpotential with the best zinc dendrite suppression feature. For zinc-ion battery performance test, the quasi-solid electrolyte composites of PAM / CNFs at 1.0 %wt CNF were fabricated and employed with electrochemical properties testing, including cyclic voltammetry, galvanostatic charge-discharge, electrochemical impedance spectroscopy, and cycle stability. This optimized quasi-solid electrolyte composites reached the highest specific capacity of 134.2 mA g-1 at a current density of 0.1 A g-1 and maintained capacity retention of 90.8% of initial capacity with 94.4% coulombic efficiency after 500 cycles.

Reducing carbonation degradation and enabling CO2 sequestration in alkali-activated slag using cellulose nanofibers

This study evaluated the role of cellulose nanofibers (CNF) in reducing the carbonation degradation of alkali-activated slag (AAS) samples. AAS samples prepared with different dosages of CNF (0 %, 0.10 %, and 0.80 % by weight of the binder) were exposed to natural and accelerated carbonation for up to 90 days. The effects of carbonation on the microstructure of AAS paste samples were monitored using FTIR, XRD, TGA, MIP, and BSE/SEM. It was observed that after 90 days of natural carbonation, the control batch exhibited a reduction in compressive strength, whereas the CNF batches showed an enhancement. Notably, the CNF-containing batches maintained consistent strength over time, with no reduction in strength. Similarly, after 90 days of accelerated carbonation, CNF 0.10 % and CNF 0.80 % showed an increase in compressive strength compared to the control batch. Despite this enhancement in compressive strength, microstructural studies indicated that the addition of CNF increased the extent of carbonation, leading to a higher amount of CaCO3 formation and C–S–H/C-A-S-H decalcification compared to the control batch. The beneficial effects of CNF on the strength despite increased C–A–S–H decalcification are attributed to their reinforcing effects and the ability to form composites with CaCO3.

P(MMA-co-MAA)/cellulose nanofibers composites: Effect of hydrogen bonds on molecular mobility

Cellulose nanofibers (CNFs) nanocomposites were prepared using poly(methylmethacrylate-co-methacrylic acid) (PMMA-co-MAA) to investigate the macromolecular mobility within the composite, with particular focus on the effect of H-bonding. Dynamic mechanical analysis (DMA) and broadband dielectric spectroscopy (BDS) were used to fully characterize the molecular mobility for which the effect of the introduction of H-bond forming moieties and the addition of CNFs (5 and 15 wt%) were assessed. Despite similar Tg values (determined by Differential Scanning Calorimetry), a deeper analysis of the relaxation times associated with the α-relaxation evidenced a significant effect induced by CNFs, which is in fact slowing down the macromolecular relaxation processes. The activation energy of the β-relaxation remained unchanged despite the introduction of MAA units in the main chain and the successive addition of CNFs. However, the latter led to the appearance at low frequencies of a new β’-relaxation correlated with the interactions between the CNF surface -OH groups and the -COOH groups of the matrix. The γ-relaxation showed a 45 % increase in activation energy from PMMA to PMMA-co-MAA + CNF nanocomposites regardless of the CNF content, due to the possibility of CNFs to interact and hinder the motion of the main chain methyl groups in α position.

Preparation and characterization of poly(vinyl pyrrolidone)/cellulose nanofiber/Aloe Vera composites as a biocompatible hydrating facial mask

This study aimed to enhance the properties of polyvinylpyrrolidone (PVP) for use as biocompatible facial masks. To achieve this, nanofibers were developed by blending PVP with cellulose nanofibers (CNFs) and Aloe vera (AV) powder using electrospinning. The results showed that incorporating CNFs and AV into the PVP matrix led to the formation of smooth and uniform nanofibers. In particular, adding 3–6 wt% AV powder in PVP/CNF composites improved fiber diameter distribution and uniformity compared to pure PVP. The PVP/CNF/AV nanofibers exhibited desirable properties for facial mask applications. They displayed 86–93 % porosity, which allowed for efficient moisture absorption capacity of up to 1829 %, and excellent water vapor permeability rate of 3.92 g/m2h. The mechanical properties of the electrospun nanofiber composites were evaluated through tensile testing. The results showed that Young's modulus values decreased progressively with the addition of CNFs and AV powder to the PVP polymer matrix, indicating a plasticizing effect that enhances flexibility. The fracture strain remained similar across all composites, suggesting that CNFs and AV did not significantly weaken the PVP matrix. The tensile strength initially increased with CNF addition but decreased with incremental AV loading. Biocompatibility studies revealed that all nanofibers exhibited excellent fibroblast viability, surpassing 98 %. This indicates that incorporating CNFs and AV did not compromise cell viability, further highlighting the suitability of the PVP/CNF/AV composites for facial mask applications.

Self-Healing and Recyclable Polyurethane/Nanocellulose Elastomer Based on the Diels-Alder Reaction.

With the background of the fossil fuel energy crisis, the development of self-healing and recyclable polymer materials has become a research hotspot. In this work, a kind of cross-linking agent with pendent furan groups was first prepared and then used to produce the Polyurethane elastomer based on Diels-Alder chemistry (EPU-DA). In addition, in order to further enhance the mechanical properties of the elastomer, cellulose nanofibers (CNFs) were added into the Polyurethane system to prepare a series of composites with various contents of CNF (wt% = 0.1~0.7). Herein, the FTIR and DSC were used to confirm structure and thermal reversible character. The tensile test also indicated that the addition of CNF increased the mechanical properties compared to the pure Polyurethane elastomer. Due to their reversible DA covalent bonds, the elastomer and composites were recycled under high-temperature conditions, which extends Polyurethane elastomers' practical applications. Moreover, damaged coating can also be repaired, endowing this Polyurethane material with good potential for application in the field of metal protection.

Nanofiller‐and basalt fiber‐reinforced recycled polyamide 6 hybrid composites

AbstractThe influence of nanofillers (cellulose nanofibers (CNF) and halloysite nanotubes (HNTs)), and basalt fibers (BF) on the morphology, mechanical and thermal of recycled polyamide 6 (PA6) composites were investigated through scanning electron microscopy (SEM), mechanical testing, rotational rheometry, dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). CNF, HNTs and BF were relatively well‐dispersed in the PA6 matrix and the incorporation of these nanofillers and BF increased the strength of the matrix, which indicates a good dispersion of the nanofillers and BF. CNF and HNTs‐filled PA6 nanocomposites increased the tnsile strength by 14% and 6% compared to the neat PA6, respectively. The composites elongation at break decreased with nanofiller, BF and combined nanofillers and BF. The shear storage modulus values of PA6/20B5C, PA6/20B5H, and PA6/25B are significantly elevated compared to neat PA6, with increases of 3.7, 2.8, and 2.5 times, respectively, at an angular frequency of 100 rad/s. PA6/20B5H composites with 20 wt.% BF and 5 wt.% HNTs exhibited the highest storage modulus (9.5 GPa) from the DMA study. Thermal stability and ash content at 800°C increased with the incorporation of HNTs and BF. The DSC findings showed that the glass transition (Tg) and melting temperature (Tm) of the composites did not exhibit any notable changes when nanofillers and BF were added to the resin. The nucleation ability of PA6 was enhanced attributable to BF and hybridization of BF and nanofillers since the crystallization temperatures of PA6 in BF filled and hybrid composites were around 5°C greater than neat PA6. The results suggest hybrid composites with potential environmental characteristics and higher mechanical properties can be utilized in semi‐structural applications in automotive and construction as a sustainable and lightweight alternative to steel and other materials.Highlights The addition of HNTs, CNF, BF and hybridization of nanofillers with BF reduced the brittleness of PA6. Nanoreinforced and hybrid PA6 composites achieved higher storage modulus than neat PA6. Thermal stability and ash content increased with the incorporation of HNTs and BF. The hybrid composites have a higher complex viscosity compared to PA6. The sustainable hybrid composites can be utilized in automotive and construction industries.

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).

Construction of biodegradable superhydrophilic/underwater superoleophobic materials with CNF (cellulose nanofiber) fence-like attached on the surface for efficient oil/water emulsion separation

Superhydrophilic/underwater superoleophobic materials for the separation of oil-water emulsions by filtration have received much attention in order to solve the pollution problem of oil-water emulsion. In this paper, a fence-like structure on the surface of CNF/KGM (Konjac Glucomannan) materials by a simple method using CNF instead of metal nanowires was successfully developed based on the hydrogen bonding of KGM and CNF. The resulted organic CNF/KGM materials surface has outstanding superhydrophilic (WCA = 0°) in air and superoleophobicity (OCA≥151°) in water, which could separate oil-water mixtures with high separation efficiency above 99.14 % under the pressure of the emulsion itself. The material shows good mechanical properties because of the addition of CNF and has outstanding anti-fouling property and reusability. More importantly, the material can be completely biodegraded after buried in soil for 4 weeks since both of KGM and CNF are organic substances. Therefore, it may have a broad application prospect in the separation of oil-water emulsion because of its outstanding separation properties, simply preparation method and biodegradability.

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.

Synthesis and characterization of cellulose nanofibers from waste paper and their utilization in wood adhesion

AbstractNanocellulose extraction from lignocellulosic materials is a highly chemical and energy‐intensive process as it requires the removal of lignin and hemicellulose. Writing paper is one of the processed materials that could be used as a raw material for the extraction of nanocellulose. In this work, cellulose nanofibers (CNFs) were synthesized from paper waste using TEMPO‐oxidation followed by high‐shear microfluidization. Scanning electron microscopy and atomic force microscopy confirmed the diameter of fibers in the nano‐range and a consistent zeta potential confirmed the stability of CNF suspension in water over a long time frame. Characterization of the CNFs using Fourier transform infrared spectroscopy indicated the presence of a carbonyl group due to the oxidation process. Thermogravimetric analysis and x‐ray diffraction revealed lower thermal stability and reduction in the crystallinity index of CNFs, as compared to pulp fibers. The obtained CNFs were used successfully as the sole binding agent in the preparation of fiberboards and also utilized as a reinforcing agent for polyvinyl acetate (PVAc) adhesive in the preparation of laminated veneer lumber (LVLs). The addition of CNFs in PVAc improved the glue shear strength indicating superior bonding characteristics and also increased the water resistance of the LVLs.Highlights This work focused on cellulose nanofibers (CNFs) extraction from waste paper Obtained CNFs form stable water suspension and have a diameter of less than 15 nm Thermal stability and crystallinity index reduced after conversion to nanofibers CNFs form a complex network and act as a sole binder to make fiberboards CNFs were utilized as a reinforcing agent for PVAc in preparation of LVLs

Design, characterization, and performance evaluation of novel PVA/CS/CNF/MOP TN ionic conductive hydrogels for flexible sensors

AbstractFlexible hydrogel polymers with excellent stretchability, high conductivity, and biocompatibility are widely used to prepare flexible sensing devices. However, it remains difficult to simultaneously combine excellent tensile capacity and high ion conducting ability into a simple hydrogel material. While PVA‐based hydrogels have been developed before, this work focuses on a unique preparation method. It solves the engineering problem of making hydrogels that have both high elongation at break and high ionic conductivity. In the study, we introduced cellulose nanofibers (CNFs) into polyvinyl alcohol (PVA)/chitosan (CS) cross‐linked polymer networks to form triple network (TN) composite hydrogel. The labyrinthine three‐dimensional (3D) honeycomb through‐hole network nanostructure generated by the addition of CNF provides the hydrogel with excellent mechanical properties. Then, the simple salting‐out strategy of muriate of potash (MOP) solution gives the hydrogel superior mechanical properties and high ionic conductivity. The prepared PVA/CS/CNF/MOP TN ionic conductive hydrogel not only exhibits excellent mechanical properties (toughness up to 2.39 MJ m−3, fracture strength up to 1.78 MPa, fracture strain up to 350%) but also has impressive ionic conductivity (highest to 8.4 S m−1). The flexible hydrogel strain sensor assembled from the PVA/CS/CNF/MOP TN ionic conductive hydrogel showed remarkable sensitivity (gauge factor for 6.9) and the ability to detect human motions reliably. Besides, the hydrogel also has maintained long‐term antimicrobial and antioxidant properties. The study provided a new perspective on designing multifunctional materials featuring strong mechanical properties and high ionic conductivity, contributing to the advancement of flexible sensor technologies.

Fabrication of anti-fouling membranes of polyvinylidene fluoride (PVDF) with the addition of cellulose nanofibers (CNF)

In this study, cellulose nanofibers (CNF) were synthesized for the fabrication of polyvinylidene fluoride (PVDF) membranes using the non-solvent-induced phase separation (NIPS) technique with distilled water as the non-solvent. The hybrid membranes exhibited an asymmetric morphology, along with increased porosity and hydrophilicity with the rising concentration of CNFs. Thermal analysis revealed that all membranes are thermally stable up to approximately 430 °C, indicating their viability for high-temperature applications. Filtration tests demonstrated an enhanced permeate flux and albumin retention with the addition of CNF. The membrane with 1.5 wt% CNF increased solute retention by 19.67 % compared to the PVDF membrane. Furthermore, the hybrid membranes exhibited improved flow recovery rates and a reduction in irreversible fouling. These findings underscore the hydrophilic and anti-fouling properties of the membranes produced in this study, making them a promising solution to enhance the efficiency and sustainability of filtration and separation processes. Their significant potential for water treatment applications in the near future is highlighted.

Algal growth inhibition test with TEMPO-oxidized cellulose nanofibers

Ecotoxicity data on cellulose nanofibers (CNFs) are limited despite their wide potential applications prospects, such as structural and packaging materials, filters, coatings, foods, and cosmetics. In this study, toxicity tests of 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO)-oxidized CNFs (TEMPO-CNFs), which are one of the major CNF products commercially available in Japan, on the green alga Raphidocelis subcapitata were conducted. As nanomaterials are considered difficult-to-test substances, the Organisation for Economic Co-operation and Development has released a guidance document that provides considerations regarding ecotoxicity tests of nanomaterials. In the algal growth inhibition tests of TEMPO-CNFs, there were specific issues to be examined, including the effects of medium components on the characteristics of TEMPO-CNFs, CNF interference with algal density measurements, algal interference with CNF measurements, and the effects of ion concentration changes in the test medium by the addition of CNFs on algal growth. To examine these issues, we conducted preliminary studies and established a suitable test method for algal growth inhibition tests of TEMPO-CNFs. We confirmed that the components in the medium for algal growth inhibition tests had negligible effects on the characteristics (zeta-potential, viscosity, and morphology) and concentration stability of TEMPO-CNFs and that in vitro and in vivo fluorescence measurements were applicable for estimating the algal densities, without interference by TEMPO-CNFs. In contrast, we observed that the grown algae interfered with the CNF concentration measurements. Therefore, we established a method to correct the measured CNF concentrations by estimating the algal contribution. Furthermore, we found that the nutrient salt concentrations in the medium changed due to interactions with CNFs; however, this change did not affect algal growth. Based on the results of the preliminary studies, algal growth inhibition tests of TEMPO-CNFs were conducted using in vitro and in vivo fluorescence measurements, along with measurements of CNFs and ion concentrations in the test dispersions. The test results showed that no growth inhibition was observed on growth rate or yield even at the maximum CNF concentration of 100 mg/L, suggesting that the ecological effect of TEMPO-CNFs on algae was relatively low. The results of this study will be valuable for conducting ecotoxicity assessments on additional CNFs and comparable nanomaterials in future studies.

Combination of cellulose nanofiber and artificial fusion protein for biocementation

Biomineralization occurring in living organisms is mostly controlled by organic macromolecules such as polysaccharides and proteins. Recently, biomineralization has been attracting much attention as a green and sustainable cementation technique including enzyme-induced carbonate precipitation (EICP), where CaCO3 is formed by hydrolysis of urea by urease in the presence of calcium ions. In this study, we have developed a novel hybrid biocementation method combining CaCO3 and cellulose nanofiber (CNF). In nature, matrix proteins work as a binder at the interface of organic and inorganic materials to form hybrid biomaterials. By mimicking the natural system, we designed an artificial fusion protein to facilitate the deposition of CaCO3 on CNF. Calcite-binding peptide (CaBP) and carbohydrate-binding module (CBM) were introduced in the artificial fusion protein CaBP-CBM to connect CaCO3 and cellulose. The addition of CNF in the EICP system resulted in the formation of a number of small particles of CaCO3 compared to a non-additive system. The addition of the fusion protein CaBP-CBM to CNF led to an increase in the size of CaCO3 particles. Furthermore, the combination of CaBP-CBM and CNF provides higher strength of samples in sand solidification. Therefore, introduction of CNF and the fusion protein would be promising for novel biocementation techniques.

Bionanocomposite Based on Cassava Waste Starch, Locust Bean Galactomannan, and Cassava Waste Cellulose Nanofibers.

Natural polysaccharides are among the renewable sources with great potential for replacing petroleum-derived chemicals as precursors to produce biodegradable films. This study aimed to prepare biopolymeric films using starch extracted from the periderm and cortex of cassava roots (waste from cassava root processing), locust bean galactomannan, and cellulose nanofibers also obtained from cassava waste. The films were prepared by casting, and their physicochemical, mechanical, and biodegradability properties were evaluated. The content of cellulose nanofibers varied from 0.5 to 2.5%. Although the addition of cellulose nanofibers did not alter the mechanical properties of the films, it significantly enhanced the vapor barrier of the films (0.055 g mm/m2 h kPa-2.5% nanofibers) and their respective stabilities in aqueous acidic and alkaline media. All prepared films were biodegradable, with complete degradation occurring within five days. The prepared films were deemed promising alternatives for minimizing environmental impacts caused by the disposal of petroleum-derived materials.

IMPACT OF FILLING RATIO AND CELLULOSE NANOFIBER NANOFLUID ON THE TOTAL THERMAL RESISTANCE AND THE STARTUP OF A MINIATURE THERMOSYPHON

Thermosyphons are highly effective heat transfer devices used for thermal management in different fields, such as electronic systems, solar collectors and nuclear reactors. The working fluid within the thermosyphon provides the heat transport from the evaporator to the condenser and limits its thermal performance. In this study, the influence of filling ratio (FR) and the eco-friendly cellulose nanofiber (CNF) nanofluid concentration on the total thermal resistance and the startup of a two-phase closed thermosyphon (TPCT) at various heat loads are investigated experimentally. The working fluids are deionized water (DI) and CNF suspensions with 0.5, 1, and 2 vol.% and filling ratios were set to 25, 50, and 75%. Total thermal resistance of the TPCT was obtained using the recorded data of wall temperature distribution at the steady state of each experiment. Addition of CNF with 1 vol.% to DI at filling ratio of 75% reduced the evaporator wall temperature by 40% and 23%, also it reduced the total thermal resistance by 58.78% and 33.65% at 20 W and 80 W, respectively. Moreover, it shortened the startup duration by 33% and reduced its temperature by 42%. This paper contains important findings that prove that CNF enhanced the thermal performance of the TPCT when applying an appropriate concentration and filling ratio.