Dispersion Of Cellulose Research Articles

Preparation of modified cellulose/PBAT films and its application in food preservation

In recent years, PBAT, i.e., Poly(butylene adipate-co-terephthalate) stands out as a potential material for packaging due to its favorable characteristics. However, its high manufacturing costs, poor crystallization, and inadequate barrier properties have impeded its broader acceptance in the industry. To tackle these issues, our study introduces a novel approach by incorporating octadecylamine (ODA)-modified cellulose (OMCC) as an eco-friendly additive. OMCC not only enhances the dispersion of cellulose within the PBAT matrix but also prevents its re-agglomeration. The integration of OMCC into PBAT has led to its significant improvements in mechanical strength, UV resistance, compatibility, hydrophobicity, and effectively enhances gas barrier properties. This work provides a new and biodegradable composite film for food packaging.

Impact of fiber diameter and surface substituents on the mechanical and flow properties of sonicated cellulose dispersions

This study investigates how sonication amplitude and time affect 2 wt% cationic nanofibrils (CCNF) and microfibrils (CCMF) dispersions, focusing on mechanical properties and flow behavior. Sonication reduces fiber diameter and increases the concentration of substituent groups available for hydrogen bonding. This effect becomes significant when diameters fall below 100 nm, leading to enhanced storage and loss moduli. CCNF achieves a maximum shear modulus of 600 Pa, whereas CCMF fibers do not undergo similar size reductions. CCNF's viscosity and critical stress follow a square root relationship with sonication amplitude, due to minimal fiber size reduction at high sonication levels (smaller than 20 nm), unlike CCMF (diameter reduction up to 50 nm), which exhibits a linear increase due to more pronounced fiber fragmentation. At high sonication levels, CCNF shows an exponential rise in critical stress (up to 800 Pa), suggesting tiny fibers infiltrate the hydrogel network, thereby improving its integrity and resistance to shear stresses. By integrating theoretical models with experimental findings, this work presents a unified view of sonication's essential role in fine-tuning the mechanical and flow properties of cellulose-based materials. This research enhances understanding of cellulose dispersion behavior under sonication and provides a foundation for designing optimized cellulose-based materials.

Optimizing cellulose acetate microbead formation through premixed membrane emulsification: Unraveling critical parameters

This study explores the fabrication of cellulose acetate microbeads using the premix membrane emulsification technique and their subsequent conversion to cellulose microbeads through deacetylation, emphasizing the need for environmentally friendly alternatives to conventional synthetic microbeads. By systematically investigating critical processing parameters such as oil-to-water phase ratio, cellulose acetate concentration, dispersion solvent, drying temperature, and flux rate, we optimized the conditions for producing uniform and well-dispersed microbeads. The optimal oil-to-water phase ratio was identified at 6:1, with higher concentrations of cellulose acetate yielding better dispersion and reduced bead size. The flux rate significantly influenced the morphology of the microbeads, with lower rates favoring spherical shapes. Non-polar solvents like hexane were found to enhance bead dispersion, whereas the drying temperature showed no significant impact. The successful transformation from cellulose acetate to cellulose microbeads was confirmed by FT-IR spectroscopy, demonstrating the removal of acetyl groups and indicating complete deacetylation. Our findings provide valuable insights into the production of cellulose-based microbeads, offering a sustainable alternative for various industrial and environmental applications.

Effect of microcrystalline cellulose on the mechanical properties of flax reinforced methylmethacrylate and urethane acrylate composites

Many structural applications are attracted to natural fibre-reinforced polymeric composites due to their eco-friendliness, recyclability, and cost-effectiveness. While significant progress has been made, their interface compatibility with the polymeric matrix is still challenging. Therefore, the present study proposed a method for improving the mechanical and dynamic mechanical performance of flax-reinforced novel methylmethacrylate (Elium®) and urethane acrylate (Crestapol®) composites. The technique involved the dispersion of microcrystalline cellulose (MCC) in the matrix at different weight percentages (0.5–0.75%) to improve the fibre/matrix interface. Flax/Elium® (FE) and flax/Crestapol® (FC) composites with varying weight percentages of MCC were manufactured using the vacuum infusion method. The resulting improvements in mechanical and dynamic properties were evaluated through in-plane shear (± 45° tensile), flexural, short beam shear, and dynamic mechanical analysis (DMA). The effects of MCC on these properties of flax/Elium® were compared to those of flax/Crestapol® composites. The addition of MCC improved the in-plane shear strength (FE: 13–20%, FC: 10–17%), flexural strength (FE: 6–13%, FC: 13%) and interlaminar shear strength (FE: 9–17%, FC: 10–20%). Also, FE composite showed 7–11%, 10–14% and 10–17% higher in-plane shear, flexural and interlaminar shear strengths, respectively, compared to FC composites. The DMA results confirmed the positive effect of Elium® resin and MCC on the dynamic storage and loss modulus.

Influence of cellulose nanocrystal surface chemistry and dispersion quality on latex nanocomposite stability, film formation and adhesive properties

The different surface functional groups on carboxylated and sulfated cellulose nanocrystals (CNCs) affect the latex CNC–polymer interactions.

Low-concentration octadecylamine based nano cellulose prepared by acid hydrolysis method improving the toughness and thermal stability of epoxy resin

Modified cellulose nanocrystals were prepared by hydrolyzing softwood pulp board with acrylic acid and p-toluenesulfonic acid, and then the nano cellulose was modified by introducing Octadecylamine into the nano cellulose. Then the modified nano cellulose was dispersed in epoxy resin (EP) to obtain Octadecylamine (ODA) modified nano cellulose-based epoxy resin composites (ONCA/EP) with high strength and good toughness. Moreover, the problem of poor dispersion of nano cellulose in EP is improved. FTIR and X-ray diffraction (XRD) confirmed the modified nano cellulose.The application properties were determined through particle size analysis, thermogravimetric analysis (TGA-DSC), mechanical property analysis, TEM and SEM. ONCA/EP nano composites have excellent mechanical properties and thermal stability due to inadequate concentration of modified nano cellulose doping. The results show that by introducing 2 % ONCA only, the strength reached the highest 74.03 MPa, and the elongation at break reached 3.64 %; the residual mass at 800℃ increased by 3.68 % compared to pure EP. The research utilizes biodegradable nano cellulose for EP modification, opening up new avenues for the applying of nano cellulose in the field of materials science. It is of great significance in enhancing epoxy resin's performance, promoting sustainable materials' development, and expanding the application areas of nano cellulose.

CELLULOSE REINFORCED POLYAMIDE COMPOSITES: EFFECT OF PREPARATION METHOD ON COMPOSITE PROPERTIES

Over the years, the preparation method chosen for the preparation of cellulose reinforced nylon or polyamide (PA) composites has proven to be critical in determining the overall properties of the composites. For example, melt processing of cellulose reinforced nylon or PA composites presents challenges, such as (i) irreversible hornification of cellulose material upon drying, before melt processing; (ii) non-uniform dispersion or distribution of cellulose in the polymer matrix; (iii) thermal degradation of cellulose at elevated temperatures and (iv) structural integrity (fibrillation) and shortening of cellulose upon mechanical shearing during melt processing. All these challenges have the potential to compromise the overall properties of the prepared composites. In order to circumvent these challenges, several techniques have been used. For example, hornification, can be overcome by using a technique called wet feeding. Thermal degradation can be overcome by coating cellulose materials via either chemical or physical wrapping with a macromolecule or surfactant. The thermal degradation of cellulose can also be prevented by using in situ polymerization of PA via the ring opening polymerization technique during the manufacture of cellulose reinforced nylon composites, as well as solvent casting in formic acid/water mixtures. The incorporation of up to 50 wt% cellulose nanofibers (CNFs) in PA nanocomposites via solvent casting improved elastic modulus by 64% and tensile strength by 62%. The aim of this manuscript is to review preparation techniques of low cost, high strength composites using cellulose fibers and engineering plastics like polyamides (PAs, nylons).

Robust integration of light-driven carbon quantum dots with bacterial cellulose enables excellent mechanical and antibacterial biodegradable yarn

Due to the overuse of antimicrobial drugs, bacterial resistance became an urgent problem to be solved. In this study, carbon quantum dots (CQDs) with high photodynamic antibacterial activity were synthesized by a one-pot hydrothermal method and introduced into bacterial cellulose (BC) dispersion solution. Through a wet-spinning and wet-twisting processing strategy, bionic ordering nanocomposite macrofiber (BC/CQDs-based yarn) based on BC were obtained. The results showed that BC/CQDs-based yarn had excellent tensile strength (226.8 MPa) and elongation (22.2 %). Utilizing the light-driven generation of singlet oxygen (1O2) and hydroxyl radical (·OH), BC/CQDs-based yarn demonstrated remarkable antibacterial efficacy, with 99.9999 % (6 log, P < 0.0001) and 96.54 % (1.46 log, P < 0.0004) effectiveness against E. coli and S. aureus, respectively. At the same time, BC/CQDs-based yarn also displayed the characteristics of photothermal, fluorescent, and biodegradability. In summary, the application potential of BC/CQDs-based yarn is significant, opening up a new strategy for the development of sustainable green weaving and bio-based multi-function yarn.

Supercritical CO2 solvent exchange and removal of water from dispersed cellulose nanofiber/polylactic acid composites without an alcohol exchange step

Supercritical CO2 solvent exchange and removal of water from dispersed cellulose nanofiber/polylactic acid composites without an alcohol exchange step

Extraction of microcrystalline cellulose from cotton fiber, and application to block natural rubber as reinforcing agent

AbstractCrosslinked natural rubber (NR)/microcrystalline cellulose (MCC) composite was prepared by dry mixing of NR with MCC extracted from cotton fiber. MCC was first extracted from cotton fiber by acid hydrolysis processing, then applied to block natural rubber as a reinforcement. MCC grafted maleic anhydride (MA) was also synthesized and applied to the composites to improve the compatibility between natural rubber and cellulose. Obtained cellulose samples were subjected to infrared spectroscopy (FTIR) to confirm the purity of cellulose structure and the presence of MA grafted on MCC chains. X‐ray spectroscopy (XRD) and thermogravimetric analysis (TGA) were investigated as well to see if there was any important change after modification. NR containing microcrystalline cellulose was formulated with vulcanizing agents and microcrystalline cellulose grafted MA for characterization. Micro‐scale dispersion of microcrystalline cellulose was observed by scanning electron microscopy (SEM). MCC showed positive contributions to tensile strength and thermal properties of composites as well. Mechanical properties of vulcanized rubber containing microcrystalline cellulose grafted MA gave a slightly better value compared to the reference sample without adding of the compatible agent. The presence of reinforcements helped NR composites to reduce solvent uptake, however there was no change in tensile strength after aging test.

In-situ exfoliation of large sized h-BNNS by esterified nanocellulose to build aqueous lubricants that can switch between liquid and gel states

The development of cellulose-based aqueous dispersions provides new ideas for the preparation of green lubricants. Herein, an esterified cellulose-assisted in-situ exfoliation (ECAIE) method was used to produce large lateral sized 2D materials in cellulose dispersions which with excellent dispersion stability. Taking h-BN as an example, the ECAIE method produces NC@h-BNNS aqueous dispersion with lateral size of h-BNNS reaching 1200 nm, exhibiting excellent lubrication properties. The obtained aqueous lubricants show the ability to switch between liquid (oscillation) and gel (resting) states. This method was also extended to the production of aqueous dispersions of various other cellulose/2D materials, and the efficient lubrication of the resulting dispersions on engineered steel surfaces has been demonstrated, indicating their great potential in the field of lubrication.

Optimized Lytic Polysaccharide Monooxygenase Action Increases Fiber Accessibility and Fibrillation by Releasing Tension Stress in Cellulose Cotton Fibers.

Lytic polysaccharide monooxygenase (LPMO) enzymes have recently shaken up our knowledge of the enzymatic degradation of biopolymers and cellulose in particular. This unique class of metalloenzymes cleaves cellulose and other recalcitrant polysaccharides using an oxidative mechanism. Despite their potential in biomass saccharification and cellulose fibrillation, the detailed mode of action of LPMOs at the surface of cellulose fibers still remains poorly understood and highly challenging to investigate. In this study, we first determined the optimal parameters (temperature, pH, enzyme concentration, and pulp consistency) of LPMO action on the cellulose fibers by analyzing the changes in molar mass distribution of solubilized fibers using high performance size exclusion chromatography (HPSEC). Using an experimental design approach with a fungal LPMO from the AA9 family (PaLPMO9H) and cotton fibers, we revealed a maximum decrease in molar mass at 26.6 °C and pH 5.5, with 1.6% w/w enzyme loading in dilute cellulose dispersions (100 mg of cellulose at 0.5% w/v). These optimal conditions were used to further investigate the effect of PaLPMO9H on the cellulosic fiber structure. Direct visualization of the fiber surface by scanning electron microscopy (SEM) revealed that PaLPMO9H created cracks on the cellulose surface while it attacked tension regions that triggered the rearrangement of cellulose chains. Solid-state NMR indicated that PaLPMO9H increased the lateral fibril dimension and created novel accessible surfaces. This study confirms the LPMO-driven disruption of cellulose fibers and extends our knowledge of the mechanism underlying such modifications. We hypothesize that the oxidative cleavage at the surface of the fibers releases the tension stress with loosening of the fiber structure and peeling of the surface, thereby increasing the accessibility and facilitating fibrillation.

Effect of different types of nanocellulose on the structure and properties of gelatin films

The use of nanocellulose to enhance the performance of biopolymer films is a recent trend in food packaging. This current study aims to investigate the impact of incorporating different morphologies of nanocellulose, namely cellulose nanofibrils (CNFs), cellulose nanospheres (CNSs), and cellulose nanocrystals (CNCs), on the structures and properties of gelatin film. The FTIR confirmed the formation of triple helix structures among CNF and CNC groups due to more hydrogen bonds generated between cellulose and gelatin molecules compared to CNSs. SEM analysis revealed a uniform distribution of CNCs in gelatin but aggregated with an increase in CNC contents, while CNF and CNS groups exhibited aggregation of cellulose upon the surface of gelatin because the vast surface area of nanospheres along with the nanofibrils structure led to irregular dispersion of cellulose (especially CNSs). In comparison to the CNF5% and CNS groups, CNC and CNF2% (w/w) groups greatly improved the mechanical characteristics of the gelatin films to 131.27% EAB and 20.71 MPa TS due to strong hydrogen bond interaction, more triple helix structures, and the relatively thorough dispersion of cellulose in the gelatin film. The incorporation of nanocellulose reduced the solubility and transparency of the gelatin films. Of all the films, CNC2% film exhibited a significant reduction of water vapor permeability due to the facile and even dispersion of CNCs in the gelatin network structure. Adding nanocellulose had little impact on the gelatin films’ heat stability. Therefore, the current work may be a new viable strategy for the construction of a novel molecular network system for enhancing the effectiveness of gelatin film containing lower content of CNCs.

Rational design of glass fiber-cellulose composite separator for sodium-ion batteries

Using glass fiber scraps as matrix and highly dispersed cellulose as enhancer, composite separators are prepared by a simple slurry sieving process. The effects of different composite proportions on the microstructure, mechanical properties, ionic conductivity and electrochemical properties are studied by SEM, tensile test, AC impedance and charge-discharge test, etc. As mass composite ratio is 1:1, the thickness of composite separator is 73.9 um, tensile strength is 29.5 Mpa and ion conductivity is 0.45 × 10−3 S cm−1, respectively. Sodium-ion half-cell (NaxNi[Fe(CN)6] as cathode) assembled by above composite separator exhibits excellent cycle stability (93.3% of capacity retention after 500 cycles at 1 C), rate capability (85.1% of capacity retention at 10 C) and maintains fine interfacial stability. Compared with glass fiber separator, some performance indicators of this new composite separator have been greatly improved, suggesting its potential application prospects in sodium-ion batteries.

Oxidized cellulose nanofibers from sugarcane bagasse obtained by microfluidization: Morphology and rheological behavior

It is advantageous to understand the relationship between cellulose fiber morphology and the rheological behavior of its dispersions so that their application can be optimized. The goal of this study was to produce sugarcane bagasse-sourced cellulose dispersions with different numbers of high-pressure homogenization cycles. Microfluidization produced cellulose nanofibers (between 5 and 80 nm in diameter) with similar surface charge densities and crystallinities (measured on the resulting films). Oscillatory rheology showed that TEMPO-oxidized cellulose dispersions exhibited gel-like behavior. However, not only did the samples with more microfluidization cycles present a lower storage modulus, but the sample with 100 cycles completely lost the gel-like characteristic, presenting a viscous fluid rheological behavior. Thixotropy loop tests revealed the influence of nanofiber length on the dispersion's structure, as evidenced by the decrease in the hysteresis value along with fiber breakage. Therefore, our findings demonstrate that the rheological properties of the dispersion can be tuned according to the length of the nanofibers, allowing for targeted applications.

Synthesis and Physicochemical Properties of Acrylate Anion Based Ionic Liquids.

Two polymerizable ionic liquids (or monomeric ionic liquids, mILs) namely 1-butyl-3-methylimidazolium and choline acrylates ([C4mim]A and ChA, respectively) were synthesized using the modified Fukumoto method from corresponding chlorides. The chemical structure of the prepared mILs was confirmed with FTIR and NMR study. Investigation of the thermal properties with DSC demonstrates that both mILs have a Tg temperature of about 180 K and a melting point around 310 K. It was shown that the temperature dependence of FTIR confirm the Tg to be below 200. Both mILs exhibited non-Newtonian shear thinning rheological behavior at shear rates >4 s−1. It was shown that [C4mim]A is able to dissolve bacterial cellulose (BC) leading to a decrease in its degree of polymerization and recrystallisation upon regeneration with water; although in the ChA, the crystalline structure and nanofibrous morphology of BC was preserved. It was demonstrated that the thixotropic and rheological properties of cellulose dispersion in ChA at room temperature makes this system a prospective ink for 3D printing with subsequent UV-curing. The 3D printed filaments based on ChA, containing 2 wt% of BC, and 1% of N,N′-methylenebisacrylamide after radical polymerization induced with 1% 2-hydroxy-2-methylpropiophenone, demonstrated Young’s modulus 7.1 ± 1.0 MPa with 1.2 ± 0.1 MPa and 40 ± 5% of strength and ultimate elongation, respectively.

Temperature-mediated construction of a plantar pressure-relieving, thermally insulating, and biodegradable thick-walled cellulose sponge insole

Plantar pressure can be reduced and wearing comfort can be improved by using cushioning materials such as insoles. However, the biodegradation of most commercial insoles is difficult, incurring high disposal costs both economically and environmentally. Herein, we present a temperature-mediated approach for constructing a plantar pressure reducing, thermally insulating, and biodegradable thick-walled cellulose sponge (TWCS) insole from cotton linters. 3D Raman imaging and crystallographic test results demonstrated that freezing temperature affected the packing behavior of the dispersed cellulose at the ice crystal boundary, resulting in a marked distinction between wall thicknesses and crystallinity of sponges, from 0.36 μm and 0.39 to 7.74 μm and 0.46, at distinguishing temperatures (−25 ˚C, −78 ˚C, and − 198 ˚C). Benefiting from the thick-walled structure generated during the temperature-mediated interfacial assembly, the mechanical strength of the TWCS was significantly increased by 5.6 times to 569 kPa, accompanied by significantly enhanced structural stability, pressure-relieving, and thermal insulating characteristics. Subsequently, we designed TWCS as a biomass insole, and its performance was thoroughly examined using plantar pressure testing, thermal performance assessment, finite element simulation, and degradability investigations. The results demonstrate that TWCS can effectively decompress (1-fold pressure reduction), disperse external stresses, prevent heat loss and complete degradation within 50 days under biological conditions, and can potentially replace traditional petroleum-based sponge insoles.

One‐pot route to hyperbranched polyethylenimine‐dictated open cellular monolith as effective and charge‐selective adsorbent

AbstractThis study shows a one‐pot route to open cellular and functional monoliths. An oil‐in‐water high or medium internal phase emulsion readily forms by dropping oil into a dispersion of microcrystalline cellulose (MC) in aqueous branched polyethylenimine (PEI) solution. Crosslinking of PEI followed by removing the volatile yields an open cellular monolith. The key point of this strategy is that PEI can act as an emulsifier at high pH and simultaneously as reactants and finally as absorbing component. Results show that the rigid MC skeleton is fully covered by the flexible PEI network. The active amine content of the monolith reaches up to 3.3 mmol NH per g monolith. The open‐cellular structure stems from volume contraction. The porous monolith can sequester trace anionic dyes in water with an absorbing capacity up to 440 mg g−1 monolith, whereas the adsorption is highly charge‐selective. The monolith is pH‐recyclable and facilely separable from water.

Synthetic Celluloses as Green Fillers for the Enhancement of the Crystallization and Mechanical Properties of Poly(3-hydroxybutyrate-co-3-hydroxyvalerate)

Enzymatically synthetic cellulose is a novel green filler combining the advantage of degradability and environmental friendliness. In this work, poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [P(HB-co-HV)] nanocomposites were fabricated using the melt blending technique through the addition of slatted cellulose (SC) or disc-shaped cellulose (DC). The effects of different morphologies and weight contents of cellulose on the crystallization behavior, morphology, and interaction of P(HB-co-HV) nanocomposites were investigated and analyzed. Compared with neat P(HB-co-HV), the yield strength and elongation at break of P(HB-co-HV)/0.1 wt %-SC nanocomposites were increased by 29 and 79%, respectively, while those for P(HB-co-HV)/0.5 wt %-DC nanocomposites were increased by 34 and 59%, respectively. Differential scanning calorimetry and polarized optical microscopy results demonstrated that cellulose increased the crystallization temperature and decreased the spherulite size of P(HB-co-HV). Wide-angle X-ray diffraction results illustrated that the growth of the grain and crystal plane was affected by cellulose. Fourier transform infrared spectroscopy results indicated that strong hydrogen bonds were formed at the interface between P(HB-co-HV) and cellulose. Scanning electron microscopy images revealed the uniform dispersion of cellulose in the polymer matrix. This study entails considerable advantages for the preparation of green nanofillers and the production of biodegradable polymers with excellent mechanical properties for tissue engineering in the presence of small amounts of fillers.

The Influence of High-Intensity Ultrasonication on Properties of Cellulose Produced from the Hop Stems, the Byproduct of the Hop Cones Production.

The goal of this work is to evaluate the hop stems, a byproduct of hop cones production, as a potential source of cellulose. Hop stems contain up to 29% of cellulose. The cellulose isolation was conducted through the thermochemical treatment. After high-speed blending, the cellulose was characterized by 67% of crystallinity degree obtained from X-ray diffraction and median diameter of 6.7 nm obtained from atomic force microscopy imaging. The high-intensity ultrasonication (HIUS) was applied to reach further disintegration of cellulose fibers. The longer HIUS treatment resulted in decrease in crystallinity degree even up to 60% and decrease in the fiber diameter up to 4 nm. The Fourier transform infrared spectroscopy (FTIR) spectra showed that HIUS treatment led to changes in intermolecular hydrogen bonds. The stability of cellulose dispersions versus length of HIUS treatment was monitored over 14 days with back dynamic light scattering and laser Doppler electrophoresis methods. Obtained results are evidence that the hop stems are a potential source of cellulose and that it is possible to obtain stable dispersions after HIUS treatment. This was the first time that the properties of hop cellulose have been described so extensively and in detail after the use of HIUS treatment.