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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. • PEO can improve the triboelectric positive property of cellulose paper. • The V OC , I SC and Q SC values of PEO/CCP based TENG exhibits linear relationship with amino groups content. • The PEO/CCP based TENG can yield a maximum V OC and I SC of 222.1 V and 4.3 μA. • A human-health detection device with button battery structure was designed. • The human-health detection device can monitor physiological signals. [ABSTRACT FROM AUTHOR]

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. • Refining makes the fiber to be fluffed. • Nanorod arrays can be realized by in-situ growth of PANI on the fine fibers. • Electrical stimulation sterilization is feasible for cellulosic fibers. [ABSTRACT FROM AUTHOR]

Figure C1 KCNF-TENG builds multi-channel, fast-response self-powered wearable sensing systems for human–computer interaction and control hardware. [Display omitted] • kapok cellulose nanofiber film (KCNF) with superior optical, mechanical and biological properties was prepared. • The KCNF dielectric enhancement formed after mechanical treatment significantly improves the electrical output performance of TENG devices. • Self-powered human–computer interaction systems, e.g., five-finger input, smart medicine, and intelligent games, were established. As wearable devices in the fields of medical health, human–computer interaction, and motion detection continue to diversify in their materials and forms, they show vast application potential. Cellulose materials are emerging as prominent materials for fabricating flexible wearable electronic devices because of their favorable skin compatibility, cost-effectiveness, and abundance. However, there is little research on the use of kapok cellulose in wearable electronics. This study addresses this knowledge gap by exploring the high-yield production and waste recycling potential of kapok cellulose. To overcome the limitations of conventional cellulose films, such as poor flexibility, high haze, and limited light transmittance, a kapok cellulose nanofiber film (KCNF) with a transparency of > 90 % and a tensile strain of > 20 % is prepared. The use of the KCNF as a friction electric material in the triboelectric nanogenerator (TENG) improves its electrical output performance by 228 % and permits its comfortable long-term attachment to the skin for self-powered tactile sensing applications, including game control, text input, and smart medical devices. This study demonstrates that the exploration of KCNF materials expands the options available for developing wearable electronic devices with numerous potential applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • GCOS with high DS was firstly synthesized in an acid-free aqueous medium. • The MIC of GCOS against S. aureus and E. coli is only 1/8 of COS. • GCOS-CFs show excellent antibacterial and antiviral activity. • Antibacterial and antiviral activities of GCOS-CFs are stable to water and heat. The worldwide spread of COVID-19 has put a higher requirement for personal medical protective clothing, developing protective clothing with sustained antibacterial and antiviral performance is the priority for safe and sustaining application. For this purpose, we develop a novel cellulose based material with sustained antibacterial and antiviral properties. In the proposed method, the chitosan oligosaccharide (COS) was subjected to a guanylation reaction with dicyandiamide in the presence of Scandium (III) triflate; because of the relatively lower molecular weight and water solubility of the COS, GCOS (guanylated chitosan oligosaccharide) with high substitution degree (DS) could be successfully synthetized without acid application. In this instance, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the GCOS were only 1/8 and 1/4 of that of COS. The introduction of GCOS onto the fiber endowed the fiber with extremely high antibacterial and antiviral performance, showing 100% bacteriostatic rate against Staphylococcus aureus and Escherichia coli and 99.48% virus load reduction of bacteriophage MS2. More importantly, the GCOS modified cellulosic fibers (GCOS-CFs) exhibit excellent sustained antibacterial and antiviral properties; namely, 30 washing cycles had negligible effect on the bacteriostatic rate (100%) and inhibition rate of bacteriophage MS2 (99.0%). Moreover, the paper prepared from the GCOS-CFs still exhibited prominent antibacterial and antiviral activity; inferring that the sheeting forming, press, and drying process have almost no effect on the antibacterial and antiviral performances. The insensitive of antibacterial and antiviral activity to water washing (spunlace) and heat (drying) make the GCOS-CFs a potential material applicable in the spunlaced non-woven fabric production. [ABSTRACT FROM AUTHOR]

The worldwide outbreak of SARS-CoV-2 has attracted extensive attention to antibacterial and antivirus materials. Cellulose is the most potential candidate for the preparation of green, environmentally friendly antibacterial and antiviral materials. Herein, modified cellulosic fibers with sustained antibacterial and antiviral performance was prepared by introducing chitosan oligosaccharide onto the fibers. The two-step method is proved to be more effective than the one-step method for enhanced chitosan oligosaccharide loadings and antibacterial and antiviral activity. In this instance, the modified fibers with 61.77 mg/g chitosan oligosaccharide loadings can inhibit Staphylococcus aureus and Escherichia coli by 100 % after contacting with bacteria for 12 h and reduce the bacteriophage MS2 by 99.19 % after 1 h of contact. More importantly, the modified fibers have washing durable antibacterial and antiviral activity; the modified fibers have 100 % antibacterial and 98.38 % antiviral activity after 20 washing cycles. Benefiting from the excellent performance of the individual fibers, the paper prepared from the modified fibers show great antibacterial (100 %) and antiviral performance (99.01 %) and comparable mechanical strength. The modified fibers have potential applications in the manufacture of protective clothing and protective hygiene products. • Chitosan oligosaccharide is used to prepare cellulosic fibers with antibacterial and antiviral performance. • Two-step method is proved to be effective in COS loadings and antibacterial and antiviral performance. • The modified fibers show excellent antibacterial and antiviral activity. • The modified fibers show excellent antibacterial and antiviral durability against washing. • The paper made from modified fibers still exhibits excellent antibacterial and antiviral performance. [ABSTRACT FROM AUTHOR]

[Display omitted] • A cocklebur structured fiber design was developed for polypyrrole modified fibers. • Formation of fibrous polypyrrole on the modified-fiber surface with high yield. • An all-in-one paper supercapacitor was produced with the papermaking technology. • Electrodes and separator were integrated by the inter-layer bonding of paper. In the era of miniaturization, low-cost, high mechanical stability and lightweight are the pre-requisites for the commercialization of smart-wearable supercapacitors (SCs). For this purpose, light-weight, binder-free, sustainable cellulose based thin-films with conductive polymers such as polypyrrole (PPy) have attained considerable attention. However, the delamination of the conductive materials in sandwich-type structures of SCs, particularly during the cyclic bending process at high current densities, is a great challenge for wearable SCs. To circumvent the problem of delamination of conductive materials, multi-layer forming concept that consists of three sequential steps (forming, pressing and drying) in papermaking technology has inspired us to prepare mechanically ultra-stable paper electrodes towards for wearable SCs. For this reason, we firstly adopted the multi-layer concept to design all-in-one paper flexible SCs by integrating PPy-modified cellulose fibers as electrodes, and un-modified cellulose paper as a separator. More importantly, a cocklebur like structure of PPy-modified cellulose fiber has been attained by the virtue of the strong inter-molecular hydrogen bonding between free hydroxyl groups on the surface cellulose fibers and PPy, resulting in increased PPy loading, and thus enhancing the electrochemical properties of the all-in-one paper supercapacitor. Furthermore, these hydroxyl groups facilitate the inter-layer bonding of the paper structure in the subsequent pressing and drying processes, favoring the integration of the electrodes and separator. Benefiting from the multi-layer forming concept and suitable morphology of PPy- modified cellulose, we have prepared an ultra-thin (150 μm) all-in-one paper SC with high areal specific capacitance (up to 562 mF cm−2), high energy density (up to 3.1 mWh cm−3) and high-power density (up to 414.9 mW cm−3). Moreover, the all-in-one paper SC shows excellent flexibility, with negligible specific capacitance loss by bending at 0° to 180° angles after repeating 1000 times. The proposed concept and supercapacitor fabrication process is scalable and can be readily implemented in a modern paper industry. [ABSTRACT FROM AUTHOR]