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As the most abundant renewable resource, cellulose fibers are potential candidates for use in health-protective clothing. Herein, we demonstrate a novel strategy for preparing cellulose fiber with prominent antibacterial and antiviral performance by the synergistic effect of amino groups and sulfonic acid groups. Specifically, guanylated chitosan oligosaccharide (GCOS) and N-sulfopropyl chitosan oligosaccharide (SCOS) were synthesized and chemically grafted onto cellulose fibers (CFs) to endow the fibers with antibacterial and antiviral properties. Moreover, a compounding strategy was applied to make the fibers with simultaneously high antibacterial and antiviral activity, especially in short contact time. The bacteriostatic rate (against S. aureus: 95.81 %, against E. coli: 92.07 %, 1 h) of the compounded fibers improved substantially when a few GCOS-CFs were mixed with SCOS-CFs; especially, it was much higher than both the individual GCOS-CFs and SCOS-CFs. By contrast, the improvement of the antiviral properties was less dramatic; however, even a few SCOS-CFs was mixed, the antiviral properties increased pronouncedly. Although the electrostatic interaction between SCOS and GCOS can make the SCOS-GCOS mixture lose some extent of antibacterial activity, the long chains of cellulose restrain the electrostatic interaction between sulfonic and amino groups, leading to their synergistic action and eventually superior antibacterial and antiviral effects., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Bacteria and virus infections have posed a great threat to public health and personnel safety. For realizing rapid sterilization of the bacteria and virus, electrical stimulation sterilization was adopted to endow cellulose fibers with instantaneous antibacterial and antiviral properties. In the proposed strategy, the fiber is fluffed by mechanical refining, and then by means of the hydrogen bond between hydroxyl and aniline, the polyaniline (PANI) directionally grows vertically along the fine fibers via in-situ oxidative polymerization. Benefiting from the conductive polyaniline nanorod arrays on the fiber stem, the paper made from PANI modified refined fibers (PANI/BCF/P) exhibited excellent antibacterial and antiviral activity, the inhibition rates against S. aureus, E. coli, and bacteriophage MS2 can up to 100 %, 100 %, and 99.89 %, respectively when a weak voltage (2.5 V) was applied within 20 min. This study provides a feasible path for plant fiber to achieve efficient antibacterial and antiviral activity with electrical stimulation, which is of great significance for the preparation of electroactive antibacterial and antiviral green health products., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Recently, cellulose paper based triboelectric nanogenerators (CPTENGs) has gained widely attention due to the development of wearable, green and miniaturized electronic products. Modification of cellulose fibers or paper is a feasible method to improve the output performance of CPTENGs, however, the simple and effective routes to improve the triboelectric property of cellulose paper still remain a challenge. Herein, we report a simple method to prepare PEO/cellulose composite paper (PEO/CCP) via mixing polyethylene oxide (PEO) with cationic cellulose fibers. Benefiting from amino groups and PEO, the composite paper exhibits higher triboelectric positive property and triboelectric charge density, thereby endowing PEO/CCP based TENG with outstanding output performance. The voltage, current and power density peak values of PEO/CCP based TENG exhibited linear relationship with amino groups content; in this instance, the performance of the TENGs can be readily adjusted by the amino groups. The voltage, current and power density of PEO/CCP based TENG can be up to 222.1 V, 4.3 μA, and 217.3 mW•m -2 , respectively. Moreover, a human-health detection device based on this TENG can monitor the physiological signals such as eye muscles, respiration, heart beat and wrist pulse, promising potentials for applications in human health-care., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Aqueous EmimAc has been proved as a novel solvent for the selective separation of hemicellulose from chemical pulp. In this work, aqueous NaOH (NaOH-a) has been incorporated into the EmimAc solution to improve the hemicellulose separation. The interaction between NaOH-a and EmimAc has been investigated. In contrast to EmimAc/H2O system, EmimAc/NaOH-a shows better separation of hemicellulose from chemical pulp. In this case, introduction of NaOH with concentration 3–5% has negligible effect on crystal structure and DP of cellulose. Moreover, a dilute NaOH (3–5%) introduction can reduce the viscosity of the pulp-EmimAc/NaOH-a system, which is beneficial for the subsequent separation process. In addition, concentrated NaOH-a (7–10%) will lead to a substantial cellulose dissolution and therefore significant viscosity increase. The further study indicates that addition of NaOH to the aqueous EmimAc can weaken the acidity of hydrogen bond (α) and increase the net basicity (β − α), which are beneficial for the hemicellulose separation. [ABSTRACT FROM AUTHOR]

In this work, a simple two-stage pretreatment (TSP) was utilized to improve hemicellulose separation and alleviate lignin condensation and therefore facilitate hemicellulose extraction and subsequent kraft pulping. In contrast to single-stage pretreatment, TSP showed a significant improvement for hemicellulose extraction and hemicellulose degradation and provided an almost identical cellulose loss. The hemicellulose separation efficiency was significantly improved using TSP with 60 min first followed by 30 min. More importantly, proper pretreatment is beneficial to the subsequent delignification; extensive pretreatment can retard delignification. [ABSTRACT FROM AUTHOR]

Due to the detrimental effects induced by transition metals on oxygen delignification, it is necessary to explore effective cellulose protector for improving the oxygen delignification efficiency. In this work, chitosan/tripolyphosphate microspheres (C/TPP) with different size were prepared and introduced for alleviating the transition metal ions effects on cellulose degradation. The results showed that both size and amount of C/TPP had a significant effect on cellulose degradation but negligible influence on lignin; C/TPP with suitable amount and smaller size was favored for cellulose protection and thus selectivity improvement. C/TPP is found to be comparable to MgSO4 and more outstanding for the pulps with extra metals; in this case, C/TPP leads only a marginal impairment in lignin degradation and removal, but provides a significant improvement for cellulose viscosity. Moreover, C/TPP is substantially more effective when is used in a combination with MgSO4. [ABSTRACT FROM AUTHOR]

Herein, an ionic liquid/water (IL/w) system was developed to separate hemicelluloses from the chemical pulp with enhanced efficiency by employing xylanase. In the traditional IL/w process, when the water content was in the range 20-15%, the extraction of hemicelluloses was 71–80%. However, the highly efficient hemicelluloses removal was always accompanied with an increased cellulose loss. In this regard, xylanase (X) pretreatment was introduced to facilitate the IL/w process for improving the separation selectivity/efficiency of the hemicelluloses. In the case of the IL/w-20 (water content is 20%) procedure, X 30 (30 mg/g xylanase) pretreatment could increase hemicelluloses removal from 71 to 78%, while the separation selectivity increased from 11.0 to 43.8. Additionally, X pretreatment also reduced IL usage/charge to achieve the same degree of hemicelluloses removal. [ABSTRACT FROM AUTHOR]

This study was to determine the effect of fiber hornification on the viscosity decrease of prehydrolysis kraft-based dissolving pulp using a commercial endoglucanase-rich cellulase. Three pulp samples, namely never-dried (ND), air-dried (AD) and oven-dried (OD), were used. The results showed that the enzymatic performance in the viscosity decrease was affected by the fiber history: the ND sample showed the strongest viscosity drop, followed by the AD sample, and the lowest was obtained from the OD sample. These results were explained by the concept of cellulose accessibility to cellulase (CAC), which decreased with the increasing degrees of hornification (DH) in the order of ND, AD and OD samples. The CAC of the samples and the cellulase adsorption on the samples were highly correlated to the DH, which consequently influenced the enzymatic treatment efficiency in viscosity control. The kinetics of the viscosity decrease during the cellulase treatment, showed an initial rapid phase, followed by a slow phase. [ABSTRACT FROM AUTHOR]

X-ray photoelectron spectroscopy (XPS) was used to trace pseudo lignin formation during the hydrothermal pretreatment of holocellulose and elaborate the structure of the isolated pseudo lignin. The results showed that XPS could detect the trace amounts of pseudo lignin in the pretreated holocellulose substrate by quantitative determination of carbon (C) and oxygen (O), while fourier transform infrared spectroscopy (FT-IR) and solid-state cross polarisation magic angle spinning carbon-13 nuclear magnetic resonance (CP/MAS C-NMR) almost had no responses. After extensive pretreatment, C increased from 8.9 to 23.0 %, O/C decreased from 0.68 to 0.54 along with an increase of Klason lignin of the pretreated holocellulose from 1.0 to 6.2 %. As for isolated pseudo lignin, both O and O were involved, whereas only O involved in reference lignin and O in holocellulose sample. In comparison to reference lignin, pseudo lignin was rich in C and less in C, suggesting that more cyclic structures and hydroxyl groups were present in the pseudo lignin. The FT-IR and NMR results identified the presence of more aliphatic structures in the pseudo lignin, especially those formed initially; while the subsequent pretreatment could modify the aliphatic toward to aromatic structure. [ABSTRACT FROM AUTHOR]

Cellulose paper has been functionalized by nanoparticles such as Ag nanoparticles, TiO2, and BaTiO3 for versatile applications including supercapacitor, sensors, photoactivity, and packaging. Herein, zinc oxide (ZnO) nanosheet-modified paper (ZnO@paper) with excellent antibacterial properties was fabricated via a mild ZnCl2-urea eutectic solvent. In this proposed method, cellulose fibers as the raw material for ZnO@paper were treated by an aqueous solvent of ZnCl2-urea; the crystalline region was destroyed and [ZnCl]+-based cations were adsorbed on the surface of cellulose fibers, facilitating more ZnO growth on ZnO@paper. A flexible paper-based triboelectric nanogenerator (P-TENG) was made of ZnO@paper paired with a PTFE film. The P-TENG presents high triboelectric output performance and antibacterial activity. For instance, the output voltage and current of the P-TENG were 77 V and 0.17 μA, respectively. ZnO@paper showed excellent antibacterial activity against E. coli and S. aureus, suggesting that a P-TENG can restrain and kill the bacteria during the working process. The results also indicated that ZnO could improve the surface roughness of cellulose paper, enhancing the output performance of a flexible P-TENG. In addition, the potential application of a P-TENG-based pressure sensor for determining human motion information was also reported. This study not only produced a high-performance P-TENG for fabricating green and sustainable electronics, but also provides an effective and novel method for ZnO@paper preparation. [ABSTRACT FROM AUTHOR]

• Natural cellulose becomes a promising material for achieving a sustainable society. • The RCF is easily manufactured by a non-derivative process of cellulose. • Conductive materials are introduced for preparing CRCF. • CRCF feathers gorgeous potential for electronic device applications. Natural cellulose features the outstanding merits of biodegradability, large-volume production and worldwide availability, which has become a promising material for achieving a sustainable society. Based on a simple dissolution-regeneration process of natural cellulose, the flexible, transparent, and smooth regenerated cellulose film (RCF) can be easily manufactured. The RCF can become conductive by introducing the conductive materials, which has presented potential applications for high-performance electronic devices. Herein, we summarized the mainly non-derivative solvents for the preparation of the RCF as well as the conductive materials for manufacturing the conducive regenerated cellulose film (CRCF). In addition, the CRCF-based versatile electronic device were also introduced. [ABSTRACT FROM AUTHOR]

Highlights • [Amim][Cl] and [Bmim][Cl] was more suitable for preparing quality film. • A decrease of DP resulted in a higher crystallinity index. • Crystal structure governs the properties of the film. Abstract Three ionic liquids (ILs) with increasing dissolution power, 1-butyl-3-methylimidazolium chloride ([Bmim][Cl]), 1-allyl-3-methylimidazolium chloride ([Amim][Cl]), and 1-ethyl-3-methylimidazolium acetate ([Emim][Ac]), were selected for cellulose dissolution and film preparation through regeneration. The physical properties of the films were investigated, and the correlation between the IL used and the film properties was evaluated. The results indicated that the superior cellulose dissolution system, [Emim][Ac], had the most difficult regeneration process (i.e., more time was required for gel formation), followed by [Amim][Cl], and [Bmim][Cl]. On the other hand, the film produced from [Amim][Cl] had the highest crystallinity, transparency, and tensile strength, followed by the films produced from [Bmim][Cl] and [Emim][Ac]. It was inferred that stronger and more ordered molecular arrangements and inter-molecular interactions preferentially occurred during cellulose regeneration from [Amim][Cl] than during cellulose regeneration from [Bmim][Cl] and [Emim][Ac]. [ABSTRACT FROM AUTHOR]

Keeping in view the huge demands of green and flexible supercapacitors to further digitalize and electrify human community, it is imperative to develop cost-effective and eco-friendly solutions. Herein, we report a sequential protocol to fabricate flexible, lightweight and inexpensive cellulose fiber thin film electrode based on vertically aligned polyaniline (PANI) nano-dendrites@fiber for supercapacitors. In this process, the mechanical shearing not only induces the branched architecture on cellulose fibers, but also promotes the subsequent growth of vertically aligned nano-dendrites of PANI on the cellulose fibers with increased PANI loading. The high fibrillation caused by mechanical shearing and the well-ordered growth of vertically aligned PANI dendrites on cellulose fibers make the resultant PANI@Paper hierarchically porous with high specific surface area, conductivity, mechanical strength and flexibility. The PANI@Paper based supercapacitor demonstrates excellent specific capacitance of 296 Fg-1 at 1 Ag-1 and areal capacitance of 5017 mF cm−2 at 10 mA cm−2. Furthermore, a solid-state supercapacitor based on PANI@Paper demonstrates excellent capacitance (282 Fg-1 at 1 Ag-1), high energy density (2.5 Wh kg−1) and power density of (0.3 kW kg−1). Impressively, all-paper supercapacitor fabricated with PANI@Paper and commercial paper shows remarkable capacitance (271 Fg-1 at 1 Ag-1) and flexibility while maintaining the electrochemical stability. [Display omitted] • Novel vertically aligned PANI nano-dendrimers@CF as a flexible electrode for SCs. • Synthesis of PANI nano-dendrimers@CF via mechanically enhanced polymerization method. • PANI nano-dendrimers@CF based electrodes for the mass production of all-paper SCs. • The PANI@Paper electrode delivers excellent areal capacitance of 5017 mF cm−2. [ABSTRACT FROM AUTHOR]

• The asymmetric hydrogel is adjusted and assembled by lignin and cellulose derivatives. • The hydrogel exhibits completely asymmetric adhesion, strength, and electriferous. • The hydrogel-based sensor has excellent skin adaptability and application stability. • The hydrogel can be applied to self-adhesive bioelectrodes and self-powered sensors. Mechanical adaptability, great wearability, application stability, and self-powered sensing characteristics are important requirements for hydrogel-based strain sensors. In this study, a novel double-layer hydrogel was fabricated with asymmetrical adhesion, strength, and electriferous properties. Wherein, the lignosulfonate sodium (LS)-borax mediated bottom hydrogel layer exhibits excellent softness (Young's modulus: ~14.2 kPa) and skin-adhesion (Adhesive strength: ~18.7 kPa) while the quaternary hydroxyethyl cellulose (QHEC) mediated top hydrogel layer demonstrates great mechanical strength (Young's modulus: ~101.3 kPa) and non-adhesive (Adhesive strength: ~2.2 kPa) properties. These complementary asymmetrical adhesion and strength properties endow the hydrogel-based sensor with exceptionally stable sensing performance and adaptive wearability; moreover, the lignocellulosic materials utilization plays a significant role in the designability, antibacterial and biodegradable properties. In addition, the synergy of negative LS (-) and positive QHEC (+) particles enables the double-layer hydrogel great self-powered sensing because of the directional movement of free ions initiated by the external mechanical stimulus. This study presents a hierarchical design idea of wearable electronics, which will have potential applications in many fields from wearable bioelectrodes to self-powered sensors. [ABSTRACT FROM AUTHOR]