Interactions between microfibrillar cellulose and carboxymethyl cellulose in an aqueous suspension

Eco-Friendly Lithium Separators: A Frontier Exploration of Cellulose-Based Materials

Lithium-ion batteries, as an excellent energy storage solution, require continuous innovation in component design to enhance safety and performance. In this review, we delve into the field of eco-friendly lithium-ion battery separators, focusing on the potential of cellulose-based materials as sustainable alternatives to traditional polyolefin separators. Our analysis shows that cellulose materials, with their inherent degradability and renewability, can provide exceptional thermal stability, electrolyte absorption capability, and economic feasibility. We systematically classify and analyze the latest advancements in cellulose-based battery separators, highlighting the critical role of their superior hydrophilicity and mechanical strength in improving ion transport efficiency and reducing internal short circuits. The novelty of this review lies in the comprehensive evaluation of synthesis methods and cost-effectiveness of cellulose-based separators, addressing significant knowledge gaps in the existing literature. We explore production processes and their scalability in detail, and propose innovative modification strategies such as chemical functionalization and nanocomposite integration to significantly enhance separator performance metrics. Our forward-looking discussion predicts the development trajectory of cellulose-based separators, identifying key areas for future research to overcome current challenges and accelerate the commercialization of these green technologies. Looking ahead, cellulose-based separators not only have the potential to meet but also to exceed the benchmarks set by traditional materials, providing compelling solutions for the next generation of lithium-ion batteries.

Cellulose Nanostructures as Tunable Substrates for Nanocellulose-Metal Hybrid Flexible Composites

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.

Spray drying of non-chemically prepared nanofibrillated cellulose: Improving water redispersibility of the dried product

Despite increasing interest in using nanofibrillated cellulose (NFC) as food thickener and emulsifier, poor water redispersibility of dried NFC, which is form suitable for practical utilization, significantly limits such applications. Studies are lacking on preparation of dried NFC with superior redispersibility. The present study therefore proposed and examined strategies to improve water redispersibility of spray dried NFC via the use of selected co-carriers, i.e., gum Arabic with/without xanthan gum, carboxymethyl cellulose or pectin. Synergistic interactions between NFC and co-carriers, as confirmed by X-ray diffraction (XRD) patterns and Fourier transform infrared (FTIR) spectra, helped prevent NFC agglomeration during spray drying. All reconstituted spray-dried NFC/co-carriers suspensions exhibited shear-thinning and gel-like behaviors, thus supporting the use of such suspensions as thickener and emulsifier. Spray-dried NFC with 80% gum Arabic and 20% xanthan gum (SD-NFC/GA20XG) resulted in suspension with highest viscosity; the suspension also performed best at recovering viscous characteristics of NFC. Water thickened by SD-NFC/GA20XG had strongest shear-thinning behavior, indicating that SD-NFC/GA20XG suspension resulted in smoothest mouth feel and easiest swallowing. Such observations were supported by XRD patterns of SD-NFC/GA20XG, which suggested that its relative crystallinity was the lowest. Its FTIR spectra also showed the highest intensity of -OH bending and carbonyl bands, which are directly related to water adsorption capability of NFC. Use of reconstituted SD-NFC/GA20XG as emulsifier also resulted in highest stability for oil-in-water (O/W) Pickering emulsion during storage for up to 30 days.

Effects of different moisture contents on the structural and functional properties of cellulose with cell wall components in different citrus fibres

This research used a multi-method approach to analyse the influence of different moisture levels (low, medium and high) on the structural and functional properties of cellulose with cell wall materials such as pectin, lignin, and hemicellulose present in citrus fibres. The influence of the drying and purification processes and the source of the citrus fibres on these interactions were also considered. A fluidized bed dryer results in a higher aggregation of cellulose fibres, which limits their interactions with water, pectin, lignin, and hemicellulose. Citrus fibre suspension produce by a alcohol washing in combination with a centrifugal drying process showed higher storage modulus (G'), loss modulus (G'') and water retention capacity. The compositions of the citrus fibres and the type of hydrogen bonding (analysed by FTIR) play a key role in generating stable rheological and thermal properties as well as controlling the moisture sorption behaviour of the citrus fibres.

A novel environmentally friendly nanocomposite aerogel based on the semi-interpenetrating network of polyacrylic acid into Xanthan gum containing hydroxyapatite for efficient removal of methylene blue from wastewater

Eco-friendly nanocomposite aerogels were prepared as adsorbents for the removal of a model pollutant (methylene blue, MB) from water. These aerogels were comprised of hydroxyapatite (HA) nanoparticles embedded within a polymer matrix consisting of a semi-interpenetrating network of xanthan gum (XG) and polyacrylic acid (PAA). Microscopy and BET analysis showed that the aerogels formed had a nanofibrous porous microstructure with a surface area of 89 m²/g. Rheological analysis showed that the aerogels were viscoelastic materials whose elasticity increased with increasing HA concentration (up to 5 w/w%). The aerogels were effective at removing MB from water, exhibiting an adsorption capacity of 130 mg/g after 200 min. The binding of the MB to the aerogels was mainly attributed to hydrogen bonding and electrostatic attraction. A reusability test showed that the MB removal efficiency of over 86% was preserved after 10 cycles of adsorption-desorption. These results suggest that our nanocomposite aerogels may be useful for the efficient removal of anionic pollutants from wastewater and water supplies due to their ease of synthesis, cost-effectiveness, good mechanical properties, high thermal stability, and good adsorption performance.

Carboxymethyl Cellulose Enhanced Production of Cellulose Nanofibrils

Cellulose nanofibrils (CNF) were produced by high-pressure homogenization from kraft pulp in the presence of carboxymethyl cellulose (CMC) of varying molecular weights. CNF pretreated with 250 kD CMC exhibited the maximum specific surface area (SSA) of 641 m2/g, which is comparable to that of CNF pretreated by 2,2,6,6-tetramethyl-piperidinyl-1-oxyl (TEMPO)-meditated oxidation with a high degree of fibrillation. Rheological and microscopic analyses also indicated a high level of fibrillation for the CMC-pretreated CNF. In contrast, the reference CNF without the CMC pretreatment showed a lower level of fibrillation, which was reflected in decreased viscosity and the reduction of SSA by a factor of 19. With the high-degree fibrillation and low toxicity, the CMC pretreatment is a promising method for the production of high-quality CNF in an environmentally friendly way.

Topochemical Engineering of Cellulose-Carboxymethyl Cellulose Beads: A Low-Field NMR Relaxometry Study

The demand for more ecological, highly engineered hydrogel beads is driven by a multitude of applications such as enzyme immobilization, tissue engineering and superabsorbent materials. Despite great interest in hydrogel fabrication and utilization, the interaction of hydrogels with water is not fully understood. In this work, NMR relaxometry experiments were performed to study bead-water interactions, by probing the changes in bead morphology and surface energy resulting from the incorporation of carboxymethyl cellulose (CMC) into a cellulose matrix. The results show that CMC improves the swelling capacity of the beads, from 1.99 to 17.49, for pure cellulose beads and beads prepared with 30% CMC, respectively. Changes in water mobility and interaction energy were evaluated by NMR relaxometry. Our findings indicate a 2-fold effect arising from the CMC incorporation: bead/water interactions were enhanced by the addition of CMC, with minor additions having a greater effect on the surface energy parameter. At the same time, bead swelling was recorded, leading to a reduction in surface-bound water, enhancing water mobility inside the hydrogels. These findings suggest that topochemical engineering by adjusting the carboxymethyl cellulose content allows the tuning of water mobility and porosity in hybrid beads and potentially opens up new areas of application for this biomaterial.

Lightweight aerogels based on bacterial cellulose/silver nanoparticles/polyaniline with tuning morphology of polyaniline and application in soft tissue engineering

Herein, polyaniline (PANI) with tuning morphology was in-situ synthesized within bacterial cellulose (BC)/silver nanoparticles hydrogels (AgNPs) that were prepared by green hydrothermal reduction method in different molarity of 0.01 and 0.25 of HCl solution along with the presence of polyethylene glycol (PEG). The synthesis of PANI in the presence of PEG in 0.01 M HCl led to the formation of rose-like morphology within nanocomposite aerogels with a size of 1.5-5.2 μm. All aerogels had the porosity and shrinkage of higher than 80% and lower than 10%, respectively. Rheology results showed a higher value of storage modulus (G') than that of loss modulus (G″) for all samples over the whole frequency regime. It confirmed by the loss factor (tan δ) value of less than 1 for all hydrogel samples. The synthesis of PANI within BC/Ag in 0.25 M of HCl solution resulted in a substantial rise of G' to nearly 1.5 × 10⁴ Pa that was one order of magnitude higher than that of other hydrogels. However, the synthesis condition of PANI did not influence the antibacterial activity. In spite of unfavorable cell attachment onto nanocomposite aerogels, the cell proliferation increased steadily over the whole period of incubation.

Rheology of regenerated cellulose suspension and influence of sodium alginate

Cellulosic colloidal suspensions present unique opportunities for rheological modification of complex fluids. In this work, the rheological behavior of regenerated cellulose (RC) suspensions, including their oscillating shear and time-dependent behavior, as well as yield stress, were studied. The rheological effects of sodium alginate's addition to aqueous RC solutions subject to shear flow were investigated. The results reveal that the RC suspension exhibited "gel-like" behavior and had a shear-thinning property. At increasing RC concentrations, the suspensions' yield stress and the extent of viscosity recovery after plastic deformation had both increased. The viscoelastic suspensions underwent a transition from "solid-like" to "liquid-like" behavior upon sodium alginate's inclusion. Sodium alginate was found to enhance RC suspensions' viscosity recoverability. Furthermore, with increasing concentrations of sodium alginate, the yield stress of RC suspension began to decrease and then vanished, occurring below the 1:1 RC: sodium alginate weight ratio with total solid content fixed at 1 wt%, due to RC's inability to form an extended network RC. This study yields insights into the rheology of RC suspensions and the influence of sodium alginate and supports both their usage as rheological modifies in applications such as coatings, drug delivery systems, and additive manufacturing techniques such as 3D printing.

A dry and fully dispersible bacterial cellulose formulation as a stabilizer for oil-in-water emulsions

Bacterial cellulose (BC) is an emerging alternative to plant cellulose in different applications. Several works demonstrated the potential of never-dried BC; however, envisioning real industrial applications, a dry product retaining its functional properties upon rehydration is preferable. A dry and completely redispersible formulation of BC with carboxymethyl cellulose (CMC) was prepared by Spray-drying. The obtained material showed a Zeta Potential of (-67.0 ± 3.9) mV, a Dv(50) of (601 ± 19.7) μm and was able to decrease the oil/water interface energy. The dry BC:CMC formulation was employed as a stabilizer in oil-in-water emulsions, in parallel with commercial plant celluloses and Xanthan gum. The emulsions were monitored over time by optical microscopy and characterized by rheological measurements. BC:CMC effectively stabilized emulsions against coalescence and creaming, at a concentration of 0.50 % - contrarily to other commercial dry celluloses - due to the Pickering effect and to the structuring of the continuous phase, as seen with Cryo-SEM.