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Flexible lithium-ion batteries (LIBs) are receiving widespread attention, and how to obtain the high flexibility, safety, and energy density of LIBs at the same time are one of the main challenges in the field of flexible electronics. The multi-network structure formed by cellulose nanofiber (TOCNF) not only provided sufficient mechanical support and excellent flexibility for the electrode but also promoted uniform distribution of conductive agents and active materials. In this work, we prepared an eco-friendly TOCNF binder from wheat straw, using a method involving 2, 2, 6, 6-tetramethylpiperidinyl-1-oxyl oxidation and high-intensity ultrasonic treatment. Additionally, we enhanced the performance of TOCNF by introducing Li+ through ion exchange, resulting in lithium-functionalized cellulose nanofibers (TOCNF-Li), which were employed as a novel binder for LiFePO4 cathodes. The findings show that, when employing TOCNF-Li binder, batteries were able to obtain an initial discharge capacity of 163 mAh g–1 at 0.1 C rate and maintained 93.2% of the initial reversible capacity after 400 cycles at 2 C rate. Notably, at 5 C rate, the discharge capacity reached 133.7 mAh g−1, with a capacity decay of only 16.1%. TOCNF-Li played a role in increasing Li+ content, opening a new pathway for Li+ transport, consequently enhancing Li+ diffusion efficiency and charge–discharge performance. Overall, TOCNF-Li serves as a novel, environmentally friendly, and efficient binder for flexible LIBs. [ABSTRACT FROM AUTHOR]

Although the hemostatically efficacious nature of cellulose nanofibers (CNFs) is well established, data regarding their hemostatic performance in large animal systems and safety toward human skin cells, which are critical factors for clinical translation, are lacking. This study evaluated the clinical potential of CNF-coated gauze by testing its hemostatic efficacy in rats, rabbits, and pigs, and assessing its safety in human primary cells through differential gene expression (DEG) analysis. In-vitro studies using rabbit blood revealed that the CNF-coated gauze exhibited a significantly lower blood clotting index (BCI) value than gauze coated with chitosan, a commonly used hemostatic agent, indicating superior blood clotting. In-vivo tests on bleeding-induced pig livers revealed that the CNF-coated gauze delivered a four-fold higher hemostatic success rate reduced bleeding volume compared to regular gauze. Moreover, a rat wound-healing model revealed improved healing with CNF-coated gauze. DEG analysis of human dermal fibroblast primary cells showed no statistically significant differences between the CNF and control groups, indicating its human safety. Overall, our results suggest that CNF-coated hemostatic gauze absorbs blood rapidly, delivers superior hemostatic performance compared to regular gauze, is safe from both histological and DEG perspectives, and is therefore suitable for use in healthcare and clinical settings.

High dielectric biobased composites of TEMPO-oxidized cellulose nanofibers (TOCNFs) reinforced with cationic modified barium titanate (BTO) nanoparticles were fabricated in this work. In order to greatly eliminate the agglomeration of the nanofiller and improve the dielectric properties of the resulting film, the modification of BTO was achieved via the cationization with an etherifying agent on the basis of cladding polydopamine around BTO. The results showed that the modified BTO nanofiller had a good interfacial compatibility and dispersion in the TOCNF matrix due to the ionic and hydrogen bonds formed between the cationic modified BTO and anionic TOCNFs. Meanwhile, the modified BTO reinforced composites exhibited better dielectric properties. Especially, the composite film with 40 wt% modified BTO exhibited an ultrahigh dielectric constant of 116.2 (at 1 kHz) and a breakdown strength of 57.7 kV/mm, which was 696% and 51.4% respectively higher than that of pure TOCNF film. It was noticed that the hydrophobicity of the composite films was also slightly improved without sacrificing its mechanical strength. [ABSTRACT FROM AUTHOR]

Dye/salt separation has gained increasing attention in recent years, prompting the quest to find cost-effective and environmentally friendly raw materials for synthesizing high performance nanofiltration (NF) membrane for effective dye/salt separation. Herein, a high-performance loose-structured NF membrane was fabricated via a simple vacuum filtration method using a green nanomaterial, 2,2,6,6-tetramethylpiperidine-1-oxide radical (TEMPO)-oxidized cellulose nanofiber (TOCNF), by sequentially filtrating larger-sized and finer-sized TOCNFs on a microporous substrate, followed by crosslinking with trimesoyl chloride. The resulting TCM membrane possessed a separating layer composed entirely of pure TOCNF, eliminating the need for other polymer or nanomaterial additives. TCM membranes exhibit high performance and effective dye/salt selectivity. Scanning Electron Microscope (SEM) analysis shows that the TCM membrane with the Fine-TOCNF layer has a tight layered structure. Further characterizations via Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) confirmed the presence of functional groups and chemical bonds of the crosslinked membrane. Notably, the optimized TCM-5 membrane exhibits a rejection rate of over 99% for various dyes (Congo red and orange yellow) and 14.2% for NaCl, showcasing a potential candidate for efficient dye wastewater treatment. [ABSTRACT FROM AUTHOR]

Nanocellulose fiber materials were considered promising biomaterials due to their excellent biodegradability, biocompatibility, high hydrophilicity, and cost-effectiveness. However, their low proton conductivity significantly limited their application as proton exchange membranes. The methods previously reported to increase their proton conductivity often introduced non-biodegradable groups and compounds, which resulted in the loss of the basic advantages of this natural polymer in terms of biodegradability. In this work, a green and sustainable strategy was developed to prepare cellulose-based proton exchange membranes that could simultaneously meet sustainability and high-performance criteria. Adenine and thymine were introduced onto the surface of tempo-oxidized nanocellulose fibers (TOCNF) to provide many transition sites for proton conduction. Once modified, the proton conductivity of the TOCNF membrane increased by 31.2 times compared to the original membrane, with a specific surface area that had risen from 6.1 m²/g to 86.5 m²/g. The wet strength also increased. This study paved a new path for the preparation of environmentally friendly membrane materials that could replace the commonly used non-degradable ones, highlighting the potential of nanocellulose fiber membrane materials in sustainable applications such as fuel cells, supercapacitors, and solid-state batteries. [ABSTRACT FROM AUTHOR]

Dye/salt separation has gained increasing attention in recent years, prompting the quest to find cost-effective and environmentally friendly raw materials for synthesizing high performance nanofiltration (NF) membrane for effective dye/salt separation. Herein, a high-performance loose-structured NF membrane was fabricated via a simple vacuum filtration method using a green nanomaterial, 2,2,6,6-tetramethylpiperidine-1-oxide radical (TEMPO)-oxidized cellulose nanofiber (TOCNF), by sequentially filtrating larger-sized and finer-sized TOCNFs on a microporous substrate, followed by crosslinking with trimesoyl chloride. The resulting TCM membrane possessed a separating layer composed entirely of pure TOCNF, eliminating the need for other polymer or nanomaterial additives. TCM membranes exhibit high performance and effective dye/salt selectivity. Scanning Electron Microscope (SEM) analysis shows that the TCM membrane with the Fine-TOCNF layer has a tight layered structure. Further characterizations via Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) confirmed the presence of functional groups and chemical bonds of the crosslinked membrane. Notably, the optimized TCM-5 membrane exhibits a rejection rate of over 99% for various dyes (Congo red and orange yellow) and 14.2% for NaCl, showcasing a potential candidate for efficient dye wastewater treatment.

Mixed matrix membranes (MMMs) are expected to be strong competitors in gas separation membranes. Nevertheless, the poor interaction between fillers and matrix is a major restriction to prepare MMMs with a higher separation performance. In this work, MIL-101(Cr) was functionalized with −NH2, −COOH, and benzenesulfonic acid (−PhSO3H) group and these functionalized MIL-101 particles were embedded in cellulose nanofibers (CNFs) to form MMMs. The interaction effect of functionalized MIL-101 with CNFs on the separation performance was discussed. After the adjustment of MIL-101-NH2 loading, the resulting MIL-101-NH2/CNF membrane with 5 wt% loading exhibited enhanced H2 permeance of ~ 2.56 × 10− 7 mol m−2 s− 1 Pa− 1 with H2/CO2 ideal selectivity of ~ 21.9. [ABSTRACT FROM AUTHOR]

Due to the non-healing nature of chronic diabetic wounds, a novel wound healing agent is required to provide the nutrients to wound and cover the wound surfaces. In this study, Alginate (ALG) membrane and Pluronic® F-127(P) hydrogel incorporated with alpha-tocopherol (AT) and TEMPO-oxidized cellulose nanofibers (TOCN) were designed. The ALG-TOCN-AT membrane was prepared using the casting method and P-TOCN-AT thermos-sensitive hydrogel was prepared using the cold mixing method. The gelation time of the P-TOCN-AT hydrogel was 45 ± 1.2 s at 37 °C and the viscosity of the hydrogel at 37 °C was higher than the viscosity measured at 25 °C. Further, the addition of TOCN and AT significantly improved the tensile strain of the membrane. An immediate release of AT was achieved in P-TOCN-AT gel while the ALG-TOCN-AT membrane released AT in a sustained manner. Cell proliferation study revealed the nontoxic nature of the hydrogel and membrane. Full-thickness skin wounds of diabetic rats were better healed by combined use of membrane and hydrogel compared to individual application of membrane or hydrogel. The highest neoepithelialization and angiogenesis was confirmed through CD31, CD105, and CD34 gene expression analysis. Hence, the combined application of hydrogels and membranes showed enhanced angiogenesis along with accelerated wound healing with no observable in-vivo toxicity.

• Developed cellulosic-based electrochemical sensor for tetracycline detection. • Innovative use of SWCNTs and TOCNF-PEI hybrids in sensor architecture. • Effective in detecting tetracycline in both PBS and wastewater effluent. • Compatible with large-scale production for green, versatile sensing devices. Antibiotics play a pivotal role in healthcare and agriculture, but their overuse and environmental presence pose critical challenges. Developing sustainable and effective detection methodologies is crucial to mitigating antibiotic resistance and environmental contamination. This study presents a cellulosic polymer-based electrochemical sensor by integrating TEMPO-oxidized cellulose nanofibers-polyethyleneimine hybrids (TOCNFs-PEI) with single-walled carbon nanotube networks (SWCNTs). Our research focuses on (i) conducting physicochemical and electrochemical studies of multifunctional SWCNT/TOCNFs-PEI architectures, (ii) elucidating the relationships between the material's properties and their electrochemical performance, and (iii) assessing its performance in detecting tetracycline concentrations in both controlled and more complex matrices (treated wastewater effluents). The limits of detection were evaluated to be 0.180 µmol L−1 (at the potential of 0.85 V) and 0.112 µmol L−1 (at the potential of 0.65 V) in phosphate-buffered saline solution, and 2.46 µmol L−1 (at the potential of 0.82 V) and 1.5 µmol L−1 (at the potential of 0.65 V) in the undiluted membrane bioreactor effluent sample, respectively. Further, the designed cellulosic polymer-based sensing architecture is compatible with large-scale production, paving the way for a new era of green, versatile sensing devices. These developments will significantly contribute to global efforts to alleviate antibiotic resistance and environmental contamination. [Display omitted] [ABSTRACT FROM AUTHOR]

Increasing substrate adsorption and improving molecular-recognition efficiency is important for highly sensitive antigen testing. In this study, we focused on 2,2,6,6-tetramethylpiperidine-1-oxyl-oxidized cellulose nanofibers (TOCNs) as substrates with the aim of developing high-performance TOCN films that use the characteristics of TOCNs to adsorb proteins on their surfaces in a manner that maintains their structure and activity. We aimed to expand the pore sizes of TOCN films crosslinked using poly(ethylene glycol) bis(amine) to enable molecular recognition within the TOCN films. TOCNs are closely crosslinked using metal ions, which we simulated using a polymer with a long main chain. Fourier-transform infrared spectroscopy was used to examine amide bond crosslinking. The TOCN films were also investigated by atomic force microscopy. Amounts of adsorbed protein were also determined, and the applicabilities of these films in an enzyme immunoassay were explored. TOCN films crosslinked with poly(ethylene glycol) bis(amine) led to the adsorption of higher amounts of protein than those observed for TOCN films crosslinked using metal ions, which is ascribable to their protein-adsorption properties and extended pores. They are also highly sensitive materials for use in Enzyme immune assay(EIA). [Display omitted] • TEMPO Oxidized Cellulose Nanofiber film was prepared using poly (ethylene glycol). • The applicabilities of these films in an enzyme immunoassay were explored. • TOCN films crosslinked with PEG led to the adsorption of higher amounts of protein. [ABSTRACT FROM AUTHOR]

The poor dispersibility and re-dispersibility of cellulose nanofibrils (CNFs) in various solvents and polymers have been recognized as the key factors limiting their potential applications. TEMPO oxidation, as the most common surface modification, can greatly improve the dispersion and re-dispersion of CNFs. However, the diameter of TEMPO-oxidized cellulose nanofibers (TOCNFs) has not been regulated in most researches, which was an important factor determining the dispersion and re-dispersion of TOCNFs. Herein, this work explored the effect of carboxyl groups on dispersion and re-dispersion of TOCNFs with uniform diameter in various solvents. Notably, fractal dimension was innovatively introduced to characterize the distribution of TOCNFs diameter. The fractal dimension and statistic diameter of TCONFs with different carboxyl group contents are ~1.56 and ~22 nm, demonstrating that the diameter of TOCNFs has been regulated in the same range. When the carboxyl group content is up to 1.58 mmol/g, the dispersion and re-dispersion of TOCNFs suspension in water and different organic solvents are the most uniform and stable. In a word, this work explores the dispersion and re-dispersion of TOCNFs with the uniform diameter and different carboxyl group contents, which can provide the theoretical guidance for various potential applications of nanofibrils in polymer matrix composites. • Effect of carboxyl groups on dispersion of TOCNFs with uniform diameter was revealed. • Fractal technology was innovatively introduced to analyze the diameter of TOCNFs. • The size uniformization of TOCNFs was achieved by grinding treatment (fractal dimension was ~1.56 and diameter was ~22 nm). • TOCNFs with carboxyl group content of 1.58 mmol/g exhibited the best dispersibility and stability. [ABSTRACT FROM AUTHOR]

In this study, a brand-new, easy, and environmentally friendly approach for chemically functionalizing 2,2,6,6-tetramethylpiperidinyloxyl radical (TEMPO)-oxidized cellulose nanofiber (TOCNF) to produce modified cellulose nanofiber (octadecylamine-citric acid-CNF) was proposed. Effects of octadecylamine (ODA)/TOCNF mass ratio on the chemical structure, morphology, surface hydrophobicity and oleophobicity were studied. According to Fourier transform infrared spectroscopy (FTIR) analysis, ODA was successfully grafted onto the TOCNF by simple citric acid (CA) esterification and amidation reactions. Scanning electron microscopy (SEM) showed that a new rough structure was formed on the ODA-CA-CNF surface. The water contact angle (WCA) and the castor oil contact angle (OCA) of the ODA-CA-CNF reached 139.6° and 130.6°, respectively. The high-grafting-amount ODA-CA-CNF was sprayed onto paper, and the OCA reached 118.4°, which indicated good oil-resistance performance. The low-grafting-amount ODA-CNF was applied in a pH-responsive indicator film, exhibiting a colour change in response to the pH level, which can be applied in smart food packaging. The ODA-CA-CNF with excellent water/oil-resistance properties and fluorine-free properties can replace petrochemical materials and can be used in the fields of fluorine-free oil-proof paper. [ABSTRACT FROM AUTHOR]

TEMPO (2,2,6,6‐tetramethylpiperidine‐1‐oxyl radical)‐mediated oxidized cellulose nanofibers (TOCNFs), which are derived from abundantly available wood biomass, possess uniform and ultrafine diameters of 3–10 nm and high aspect ratios, and are functionalized with carboxyl groups. The fabrication process of TOCNFs is more environmentally friendly than that of other types of cellulose, such as microfibrillated cellulose (MFC) and cellulose nanocrystals (CNCs), and TOCNFs possess a more uniform and ultrafine diameter. In recent years, TOCNF‐based adsorbents, nanocomposites, and membranes have been studied extensively in various fields, such as environmental remediation, energy, and smart materials. This review summarizes the recent advances in the applications of TOCNFs in the abovementioned fields. In particular, the preparation, adsorption ability, and removal efficiency of TOCNF‐based absorbents, separation performance of various kinds of TOCNF‐based membranes, wide applications of TOCNFs in energy storage and conversion, and TOCNF‐based smart materials are discussed. The beneficial role of TOCNFs in the abovementioned applications is highlighted, including their low environmental impact, high aspect ratio, high strength, ability to be functionalized, and renewability. It is believed that this timely review will facilitate further research on the innovation and applications of TOCNFs in fields such as environmental remediation, energy, and smart materials. [ABSTRACT FROM AUTHOR]

2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-oxidized cellulose nanofiber (TOCN) particles, an innovative biobased material derived from wood biomass, have garnered significant interest, particularly in the biomedical field, for their distinctive properties as biocompatible particle adsorbents. However, their microscopic size complicates their separation in liquid media, thereby impeding their application in various domains. In this study, superparamagnetic magnetite nanoparticles (NPs), specifically iron oxide Fe 3 O 4 NPs with an average size of 15 nm, were used to enhance the collection efficiency of TOCN-Fe 3 O 4 composite particles synthesized through spray drying. These composite particles exhibited a remarkable ζ-potential (approximately -50 mV), indicating their high stability in water, as well as impressive magnetization properties (up to 47 emu/g), and rapid magnetic responsiveness within 60 s in water (3 wt % Fe 3 O 4 to TOCN, 1 T magnet). Furthermore, the influence of Fe 3 O 4 NP concentrations on the measurement of the speed of magnetic separation was quantitatively discussed. Additionally, the binding affinity of the synthesized particles for proteins was assessed on a streptavidin-biotin binding system, offering crucial insights into their binding capabilities with specific proteins and underscoring their significant potential as functionalized biomedical materials.

Herein, the rheological properties of 2,2,6,6-tetramethylpiperidin-1-oxyl radical-oxidized cellulose nanofiber (TOCNF) suspensions individualized using high-intensity ultrasonication were investigated. The surface charge density of the nanofibers and sonication time were 0.659–1.24 mmol/g and 30–600 s, respectively. With increased surface charge density, the minimum time required for disintegration decreased due to the repulsive force between oxidized nanofibers. Additionally, increased sonication time enhanced the TOCNF nanofibrillation, thereby forming networks between the nanofibers. Further disintegrating TOCNF increased shear viscosity and yield stress of TOCNF suspensions. Based on the crowding factor theory, the relationship between the average fiber width and sonication time was found at various surface charge densities. Ultrasonication was considered as an energy saving and precisely controllable nanofibrillation method. This research shows the change of fiber shapes during the nanofibrillation process, and suggests an estimation of disintegration degree by the relationship between the rheological properties and TOCNF morphology. [ABSTRACT FROM AUTHOR]

Thanks to their considerable electrochemical and mechanical properties, fiber‐shaped supercapacitors have become the most potential energy storage devices for portable and wearable electronics in the future; however, challenges still exist in the pursuit of practical applications among them. In this work, ternary microfibers, which are composed of TEMPO‐oxidized cellulose nanofibers/reduced graphene oxide microfiber cores coated with polypyrrole shell layers, are successfully fabricated through industrializable and sustainable wet‐spinning and interfacial polymerization strategies. The prepared microfibers possess well‐defined microstructures and outstanding mechanical properties (559 MPa). When assembled into symmetrical all‐solid‐state fiber‐shaped supercapacitors (FSCs), they exhibit remarkable electrochemical properties (647 mF cm−2, 14.37 µWh cm−2 at 0.1 mA cm−2), prominent cycling stability (92.5% capacitance retention and 92.6% coulomb efficiency after 10 000 cycles), and extraordinary flexibility (no significant decay in capacitance after 5000 bending cycles), which are superior to all the congeneric FSCs reported to date. The prominent performances are ascribed to the synergistic effect of the well‐designed ternary system and synergistic effects between interior components. The advantages in electrochemical, mechanical, and industrial properties of the ternary FSCs can provide reference and boost the development of flexible energy storage applications. [ABSTRACT FROM AUTHOR]

Cellulose is the richest renewable polymer source on the earth. TEMPO-mediated oxidized cellulose nanofibers are deduced from enormously available wood biomass and functionalized with carboxyl groups. The preparation procedure of TOCNFs is more environmentally friendly compared to other cellulose, for example, MFC and CNCs. Due to the presence of functional carboxyl groups, TOCNF-based materials have been studied widely in different fields, including biomedicine, wastewater treatment, bioelectronics and others. In this review, the TEMPO oxidation mechanism, the properties and applications of TOCNFs are elaborated. Most importantly, the recent advanced applications and the beneficial role of TOCNFs in the various abovementioned fields are discussed. Furthermore, the performances and research progress on the fabrication of TOCNFs are summarized. It is expected that this timely review will help further research on the invention of novel material from TOCNFs and its applications in different advanced fields, including biomedicine, bioelectronics, wastewater treatment, and the energy sector. [Display omitted] • Recent progresses of TOCNFs are discussed. • The oxidation mechanism, characterization, properties and applications of TOCNFs are presented. • The key technologies for developing TOCNFs based smart materials with unique properties are elaborated. [ABSTRACT FROM AUTHOR]

This article presents a comparative study of the surface characteristics and water purification performance of commercially available cellulose nonwoven fabrics modified, via cast coating, with different nano-dimensioned bio-based carbohydrate polymers, viz. cellulose nanocrystals (CNC), TEMPO-oxidized cellulose nanofibers (T-CNF), and chitin nanocrystals (ChNC). The surface-modified nonwoven fabrics showed an improvement in wettability, surface charge modification, and a slight decrease of maximum pore size. The modification improved the water permeance in most of the cases, enhanced the particle separation performance in a wide range of sizes, upgraded the mechanical properties in dry conditions, and showed abiotic antifouling capability against proteins. In addition, T-CNF and ChNC coatings proved to be harmful to the bacteria colonizing on the membranes. This simple surface impregnation approach based on green nanotechnology resulted in highly efficient and fully bio-based high-flux water filtration membranes based on commercially available nonwoven fabrics, with distinct performance for particle rejection, antifouling and antibacterial properties.

The preparation of sensitive, homogeneous and reproducible surface-enhanced Raman spectroscopy (SERS) platforms is imperative for rapid in situ measurements, but remains a formidable task. We constructed a high-performance, stable and homogeneous Ag NPs-TOCNF/PAAM hydrogel SERS platform using a cellulose-based hydrogel with a porous network structure composed of TEMPO-oxidized cellulose nanofibers (TOCNF) and polyacrylamide (PAAM) to attach, coordinate and protect silver nanoparticles (Ag NPs). The -COO- group in the TOCNF is coordinated to the silver atoms, resulting in a more uniform distribution of Ag NPs. The encapsulation of hydrogel effectively protects the Ag NPs from oxidation and improves the stability of the substrate. The volume shrinkage treatment of the hydrogel can adjust the structural gap of the Ag NPs, thus exhibiting high sensitivity. The SERS performance of the hydrogel was evaluated using the molecule R6G. Its enhancement factor is up to 7.56 × 10−7. In addition, SERS activity remained above 85% even after 50 days. Finally, the Ag NPs-TOCNF/PAAM hydrogel platform was used to detect thiram in fruit peels with a detection limit of 10−6 M. In conclusion, the platform shows great promise for the determination of hazardous chemicals in the field environment. [Display omitted] • A cellulose-based hydrogel surface-enhanced Raman spectroscopy (SERS) platform with a porous network structure was prepared. • TOCNF stabilizes Ag atoms by coordination of -COO- groups with surface Ag atoms. • Hydrogel acts as a carrier and barrier to protect Ag NPs from oxidation. • The substrate is used for in situ sampling and detection of thiram in fruits and fruit juices. [ABSTRACT FROM AUTHOR]

[Display omitted] • Thermosensitive Pluronic-based hydrogel (P-TOCN-AT) and Alginate-based membrane (ALG-TOCN-AT) were designed and incorporated with Alpha-tocopherol and nanocellulose. • Incorporation of TOCN and AT into the hydrogel (P-TOCN-AT) reduced the viscosity. • AT and TOCN reduced membrane (ALG-TOCN-AT) shrinkage and enhanced its tensile strain. • Combined application of hydrogel (P-TOCN-AT) and membrane (ALG-TOCN-AT) gives best wound healing effect in a diabetic wound model compared with single application of hydrogel and membrane. Due to the non-healing nature of chronic diabetic wounds, a novel wound healing agent is required to provide the nutrients to wound and cover the wound surfaces. In this study, Alginate (ALG) membrane and Pluronic® F-127(P) hydrogel incorporated with alpha-tocopherol (AT) and TEMPO-oxidized cellulose nanofibers (TOCN) were designed. The ALG-TOCN-AT membrane was prepared using the casting method and P-TOCN-AT thermos-sensitive hydrogel was prepared using the cold mixing method. The gelation time of the P-TOCN-AT hydrogel was 45 ± 1.2 s at 37 °C and the viscosity of the hydrogel at 37 °C was higher than the viscosity measured at 25 °C. Further, the addition of TOCN and AT significantly improved the tensile strain of the membrane. An immediate release of AT was achieved in P-TOCN-AT gel while the ALG-TOCN-AT membrane released AT in a sustained manner. Cell proliferation study revealed the nontoxic nature of the hydrogel and membrane. Full-thickness skin wounds of diabetic rats were better healed by combined use of membrane and hydrogel compared to individual application of membrane or hydrogel. The highest neoepithelialization and angiogenesis was confirmed through CD31, CD105, and CD34 gene expression analysis. Hence, the combined application of hydrogels and membranes showed enhanced angiogenesis along with accelerated wound healing with no observable in-vivo toxicity. [ABSTRACT FROM AUTHOR]

2,2,6,6-Tetramethylpiperidine-1-oxyl radical (TEMPO)-oxidized cellulose nanofibers were prepared from two kraft pulps (Norway spruce and mixed eucalyptus) using the TEMPO/NaBr/NaClO system at pH 10 and 22 °C. After reaction and mechanical treatment, the TEMPO-oxidized celluloses were used for preparation of self-standing films and coatings of laminate films on 50-μm-thick polyethylene terephthalate films. Characterization of the films was performed based on water contact angle measurements, laser profilometry, scanning electron microscopy, and field-emission scanning electron microscopy. The purpose of this study is to understand how the measured contact angles are affected by the film's physical properties (morphology, thickness, density, and roughness). [ABSTRACT FROM AUTHOR]

The sluggish reaction kinetics, polysulfide shuttling and low-efficiently use of sulfur largely imped the rate performance and energy density of lithium-sulfur batteries. To overcome the bottleneck, we used 1D TEMPO-oxidized cellulose nanofibers (T-CNF) and 2D rGO nanosheets as "rebar" and "cement" to construct a tough framework, and the monolayer MXene (m-MXene) was uniformly wrapped on the framework forming a MXene-coated three-dimensional aerogel (MCG aerogel) with high ionic and electronic conductivity. It is worth mentioning that the negatively charged groups of MXene can not only accelerate the ion diffusion rate and the conversion process of polysulfides by anchoring polysulfides through strong adsorption sites, but also construct an ion selective layer to inhibit the shuttle effect of polysulfides. Moreover, the T-CNF-enhanced three-dimensional structure alleviates the negative impact of sulfur volume expansion during the charging and discharging process, making it possible to directly used the aerogel as self-supporting electrodes without any binder. Therefore, the T-CNF/rGO hybrid aerogels with monolayer MXene coating as cathode materials for Lithium-sulfur batteries exhibit high discharge capacity of 1470 mA h g−1 at 0.1 C and improved rate capability of 744 mA h g−1 at 5 C. The high-strength framework structure with uniform surface sulfur-anchor coating design strategy offers a new angle of regulatin g the diffusion kinetic rate of lithium-sulfur batteries. • Induced by the polar groups carried by T-CNF, MXene will be uniformly coated on 3D framework. • The MXene-coated 3D aerogel exhibits high efficiency for ion diffusion and electron transfer. • This MCG aerogel sulfur host material enhances the sulfur conversion reaction rate and electrochemical kinetic response rate. • Cathode material for lithium-sulfur battery with ultra-high-rate performance. • Self-supporting electrode with tough mechanical properties. [ABSTRACT FROM AUTHOR]

The interface plays a pivotal role in stabilizing metal anode. Extensive studies have been made but systematic research is lacking. In this study, preliminary studies are conducted to explore the prime conditions of interfacial modification to approach the practical requirements. Critical factors including reaction kinetics, transport rate, and modulus are identified to affect the Zn anode morphology significantly. The fundamental principle to enhance the Zn anode stability is systematically studied using the TEMPO-oxidized cellulose nanofiber (TOCNF) coating layer with thin a separator. Its advantageous mechanical properties buffer the huge volume variation. The existence of hydrophilic TOCNF in the Zn anode interface enhances the mass transfer process and alters the Zn 2+ distribution with a record high double-layer capacitance (390 uF cm -2 ). With the synergetic effect, the modified Zn anode works stably under 5 mA cm -2 with a thin nonwoven paper as the separator (thickness 113 µm). At an ultra-high current density of 10 mA cm -2 , this coated anode cycles for more than 300 h. This strategy shows an immense potential to drive the Zn anode forward toward practical applications., (© 2022 Wiley-VCH GmbH.)

In this study, cellulose nanofibers (CNF) obtained via high-pressure microfluidization were 2,6,6-tetra-methylpiperidine-1-oxyl (TEMPO) oxidized (TOCNF) in order to facilitate the grafting of ethylene glycol methyl ether acrylate (EGA). FTIR and XPS analyses revealed a more efficient grafting of EGA oligomers on the surface of TOCNF as compared to the original CNF. As a result, a consistent covering of the TOCNF fibers with EGA oligomers, an increased hydrophobicity and a reduction in porosity were noticed for TOCNF-EGA. However, the swelling ratio of TOCNF-EGA was similar to that of original CNF grafted with EGA and higher than that of TOCNF, because the higher amount of grafted EGA onto oxidized cellulose and the looser structure reduced the contacts between the fibrils and increased the absorption of water. All these results corroborated with a good cytocompatibility and compression strength recommend TOCNF-EGA for applications in regenerative medicine. • Ethylene glycol methyl ether acrylate (EGA) was grafted on cellulose nanofibers. • TEMPO oxidation of cellulose nanofibers (TOCNF) enhanced the grafting of EGA. • TOCNF-EGA showed improved thermal stability, hydrophobicity and compression strength. • The swelling ratio was influenced by the grafted EGA and the porous morphology. • EGA grafted TOCNF - a promising material in regenerative medicine. [ABSTRACT FROM AUTHOR]

To remove multiple pollutants (such as organic dyes, heavy metal ions, emulsified oil droplets, and toxic chemicals) from water resources, developing membranes with multifunctional separation performances is highly demanded. Herein, self-supported nanocomposite membranes with nanoporous structures were fabricated by integrating positively charged amyloid-like oligomers that were obtained by reducing disulfide bonds of native lysozyme onto the surface of negatively charged nanocelluloses via electrostatic interaction and hydrogen bonding. Lysozyme oligomer not only acted as adhesive to glue cellulose nanofibers prepared by 2,2,6,6-tetramethyl-1- piperidinyloxy oxidation (TEMPO), but also reduced the pore size of the resultant membranes to a precise cut-off size of 3 nm. Benefitting from the multiple functional groups (-OH, –COOH, –SH, –NH 2), the resultant nanocomposite membranes could efficiently remove organic dyes, heavy metal ions, bilirubin, oil droplets, and boron from wastewater. Moreover, these membranes showed excellent recyclability, mechanical performance, and acid/alkali resistance. This work provided a fast, economical, and sustainable strategy for the fabrication of multifunctional membranes for wastewater purification from natural resources and renewable nanomaterials. [Display omitted] • Lysozyme was used as an adhesive for the construction of nanocellulose-based membranes. • The nanocomposite membranes could efficiently remove molecules (>3 nm), oil droplets, heavy metal ions, and toxins. • The nanocomposite membranes showed excellent recyclability, mechanical performance, and acid/alkali resistance. [ABSTRACT FROM AUTHOR]

To afford an intact double network (sample abbr.: DN) hydrogel, two-step crosslinking reactions of poly(2-acrylamido-2-methylpropanesulfonic acid) (i.e., PAMPS first network) and then poly(acrylic acid) (i.e., PAA second network) were conducted both in the presence of crosslinker (N,N′-methylenebisacrylamide (MBAA)). Similar to the two-step processes, different contents of 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) oxidized cellulose nanofibers (TOCN: 1, 2, and 3 wt.%) were initially dispersed in the first network solutions and then crosslinked. The TOCN-containing PAMPS first networks subsequently soaked in AA and crosslinker and conducted the second network crosslinking reactions (TOCN was then abbreviated as T for DN samples). As the third step, various (T–)DN hydrogels were then treated with different concentrations of FeCl3(aq) solutions (5, 50, 100, and 200 mM). Through incorporations of ferric ions into (T–)DN hydrogels, notably, three purposes are targeted: (i) strengthen the (T–)DN hydrogels through ionic bonding, (ii) significantly render ionic conductivity of hydrogels, and (iii) serve as a catalyst for the forth step to proceed with in situ chemical oxidative polymerizations of pyrroles to afford polypyrrole-containing (sample abbr.: Py) hydrogels [i.e., (T–)Py–DN samples]. The characteristic functional groups of PAMPS, PAA, and Py were confirmed by FT–IR. Uniform microstructures were observed by cryo scanning electron microscopy (cryo-SEM). These results indicated that homogeneous composites of T–Py–DN hydrogels were obtained through the four-step process. All dry samples showed similar thermal degradation behaviors from the thermogravimetric analysis (TGA). The T2–Py5–DN sample (i.e., containing 2 wt.% TOCN with 5 mM FeCl3(aq) treatment) showed the best tensile strength and strain at breaking properties (i.e., σTb = 450 kPa and εTb = 106%). With the same compositions, a high conductivity of 3.34 × 10−3 S/cm was acquired. The tough T2–Py5–DN hydrogel displayed good conductive reversibility during several "stretching-and-releasing" cycles of 50–100–0%, demonstrating a promising candidate for bioelectronic or biomaterial applications. [ABSTRACT FROM AUTHOR]

This article presents a comparative study of the surface characteristics and water purification performance of commercially available cellulose nonwoven fabrics modified, via cast coating, with different nano-dimensioned bio-based carbohydrate polymers, viz. cellulose nanocrystals (CNC), TEMPO-oxidized cellulose nanofibers (T-CNF), and chitin nanocrystals (ChNC). The surface-modified nonwoven fabrics showed an improvement in wettability, surface charge modification, and a slight decrease of maximum pore size. The modification improved the water permeance in most of the cases, enhanced the particle separation performance in a wide range of sizes, upgraded the mechanical properties in dry conditions, and showed abiotic antifouling capability against proteins. In addition, T-CNF and ChNC coatings proved to be harmful to the bacteria colonizing on the membranes. This simple surface impregnation approach based on green nanotechnology resulted in highly efficient and fully bio-based high-flux water filtration membranes based on commercially available nonwoven fabrics, with distinct performance for particle rejection, antifouling and antibacterial properties.