A Self-Healing and Sweat-Chargeable Hydrogel Electrolyte for All-in-One Flexible Supercapacitors.

Flexible solid-state supercapacitors (SCs) with hydrogel as an electrolyte and separator combine the advantages of wearability and energy storage and exhibit a broad application prospect in wearable energy textiles. However, irreversible electrolyte damage and unstable electrode-electrolyte interfaces during mechanical deformations remain bottlenecks in realizing truly wearable applications. Herein, poly(acrylic acid) (PAA)-Fe hydrogels were prepared through a simple thermal polymerization strategy. The dynamic reversible metal coordination bonds between Fe3+ and carboxylic acids confers the hydrogels with excellent self-healing properties. As expected, the prepared hydrogels exhibited superior mechanical strength (tensile stress of 45.80 kPa), ionic conductivity (0.076 S cm-1), and self-healing properties. Subsequently, the SCs were constructed using composite hydrogel electrodes (MnO2@CC embedded in the PAA-Fe hydrogels) as symmetrical electrodes (marked as MSCs). The reversible metal coordination bonds between composite hydrogel electrodes formed an ultrastable electrode/electrolyte interface in the all-in-one MSCs, thus revealing excellent mechanical durability. The all-in-one MSCs delivered a remarkable specific capacitance (30.98 F g-1 at 0.2 A g-1), excellent cyclic stability (87.24% after 5000 cycles), outstanding mechanical deformation stability, and impressive electrochemical output stability after self-healing (capacitance retention of 85.34% after five cycles of cutting/self-healing). It is noteworthy that the all-in-one MSCs employed NaCl as an electrolyte, which can be obtained from human sweat. As a proof of the self-charged concept, the all-in-one MSCs can be reused in sweat, whose capacitance was maintained at 90.05% of the initial state after three repetitions. This work is expected to shine light into the design of all-in-one and fabric-based SCs and the development of wearable energy textiles.

Self-assembled bacterial cellulose-based photo-enzyme coupled system enabled by visible light-driven for efficient dye degradation.

To achieve efficient dye degradation, we reported a visible light-driven biomass photo-enzyme coupled system, which was constructed by assembling g-C3N4 during in situ culture and immobilizing laccase via metal-organic framework (MOF). Benefited from the network and porous structure of bacterial cellulose (BC), the g-C3N4 could be stably interspersed, and MOF grew g-C3N4/BC to encapsulate laccase. BC improves the reusability of the system, while combined with MOF encapsulation, avoiding direct contact between photo- and enzyme- catalysts. Importantly, thanks to the existence of electron transfer from photocatalysis to enzyme, the photogenerated electron hole recombination within the photocatalyst reduced, improving catalyzed reaction efficiency. The degradation efficiency of the catalysis system within 10 min for methylene blue and rhodamine B could reach 100 % and 96.1 %, respectively, which could rapidly degrade dye and recycle for more than 10 times. This research can shine new light on the development of advanced wastewater treatment.

Biomass confined gradient porous Janus bacterial cellulose film integrating enhanced radiative cooling with perspiration-wicking for efficient thermal management.

Sophisticated structure design and multi-step manufacturing processes for balancing spectra-selective optical property and the necessary applicable performance for human thermal-wet regulation, is the major limitation in wide application of radiative cooling materials. Herein, we proposed a biomass confinement strategy to a gradient porous Janus cellulose film for enhanced optical performance without compromising thermal-wet comfortable. The bacterial cellulose confined grow in the micro-nano pores between PP nonwoven fabric and SiO2 achieving the cross-scale gradient porous Janus structure. This structure enables the inorganic scatterers even distribution forming multi-reflecting optical mechanism, thereby, gradient porous Janus film demonstrates a reflectivity of 93.1 % and emissivity of 88.1 %, attains a sub-ambient cooling temperature difference of 2.8 °C(daytime) and 8.5 °C(night). Film enables bare skin to avoid overheating by 7.7 °C compared to cotton fabric. It reaches a 17.2 °C building cooling temperature under 1 sun radiance. Moreover, biomass confined micro-nano gradient porous structure integrating with Janus wet gradient guarantees the driven force for directional water transportation, which satisfies the thermal-wet comfortable demands for human cooling application without any further complicated process. Overall, bacterial cellulose based biomass confining strategy provides a prospective method to obtain outdoor-service performance in cooling materials.

Spray-assisted layer-by-layer deposition of quaternized chitosan/tannic acid for the construction of multifunctional bio-based nonwoven dressings.

Gauze wound dressings have received considerable attention due to their cost-effectiveness, excellent mechanical properties, and widespread applications. However, their inability to actively combat microorganisms and effectively scavenge free radicals results in suboptimal wound management. In this study, a novel nonwoven-based gauze dressing coated with quaternized chitosan/tannic acid (QCS/TA), based on electrostatic interaction and hydrogen bonding, was successfully prepared using a spray-assisted layer-by-layer assembly method. The bio-based nonwoven dressing, assembled with multiple interlacing bilayers, demonstrated outstanding antimicrobial properties, eliminating 99.99 % of Staphylococcus aureus (S. aureus) and 85 % of Escherichia coli (E. coli). Compared to the pristine nonwoven dressing, the QCS/TA-coated nonwoven dressing scavenged >85 % of the surrounding radicals within 2 h. Additionally, the nonwoven dressing exhibits excellent coagulation properties. Notably, the facile spraying procedure preserved most of the softness and breathability of the nonwoven substrate. After the deposition of seven bilayers, the bending stiffness and drape coefficient increased by only 37.63 % and 3.85 %, respectively, while the air permeability and moisture permeability reached 1712 mm/s and 3683.58 g/m2/d, respectively. This bio-based nonwoven dressing, derived from safe and non-toxic ingredients, holds promise as the next generation of multifunctional gauze dressings.

Cationic cellulose nanofiber solid electrolytes: A pathway to high lithium-ion migration and polysulfide adsorption for lithium-sulfur batteries.

Polyethylene oxide (PEO) solid electrolytes, acknowledged for their safety advantages over liquid counterparts, confront inherent challenges, including low ionic conductivity, restricted lithium ion migration, and mechanical fragility, notably pronounced in lithium­sulfur batteries due to the polysulfide shuttling phenomenon. To address these limitations, we integrate a quaternary ammonium cation-modified cellulose (QACC) nanofiber, electrospun with cellulose acetate (CA) from recycled cigarette filters, into the PEO electrolyte matrix. The nitrogen atom within the quaternary ammonium group exhibits a pronounced affinity for polysulfide compounds, effectively curtailing polysulfide migration. Concurrently, Lewis acid-base interactions between quaternary ammonium groups and lithium salt anions facilitate the release of additional Li+, achieving a lithium-ion transference number 1.5 times higher than its pure PEO counterpart. Furthermore, the introduction of a larger trifluoromethanesulfonimide (TFSI) group on the QACC macromolecule (TFSI-QACC) disrupts the ordered arrangement of PEO macromolecules, resulting in a noteworthy enhancement in ionic conductivity, reaching 2.07 × 10-4 S cm-1 at 60 °C, thus addressing the challenge of low PEO electrolyte conductivity. Moreover, the nanofiber enhances the mechanical strength of the PEO electrolyte from 0.49 to 7.50 MPa, mitigating safety concerns related to lithium dendrites puncturing the electrolyte. Consequently, the composite PEO demonstrates exemplary performance in lithium symmetrical batteries, enduring 500 h of continuous operation and completing 100 cycles at both room and elevated temperatures. This integrated approach, transitioning from waste to wealth, adeptly addresses a spectrum of challenges in the efficiency of solid-state electrolytes, holding considerable promise for advancing lithium­sulfur battery technology.

Flexible Self-Supporting MOF-Based Bean Pod Cube Hollow Nanofibers for Ultralong Cycling and High Rate Na Storage.

Sodium-ion batteries (SIBs) have garnered significant attention due to their potential as an emerging energy storage solution. Tin sulfide (SnS) has emerged as a promising anode material for SIBs due to its impressive theoretical specific capacity of 1022 mA h g-1 and excellent electrical conductivity. However, its practical application has been hindered by issues such as large volume expansion, which adversely affects cycling stability and rate performance during the charge/discharge processes. In this study, a novel approach to address these issues by synthesizing the bean pod cube hollow metal-organic framework (MOF)-SnSx/NC@N-doped carbon nanofibers through a process involving electrospinning, PDA coating, and calcination. The Sn-MOF serves as a self-sacrificing template, facilitating the simultaneous dissociation of MOF and polymerization of dopamine, leading to the creation of hollow intermediates that retain tin components. Subsequent sulfidation results in the integration of the hollow MOF-SnSx/NC nanoparticles within 3D nitrogen-doped carbon nanofibers, forming the distinctive bean pod cube composite structure. This unique configuration effectively shortens the diffusion path and mitigates volume expansion for sodium ions, ultimately yielding an exceptional high rate performance of 130 mA h g-1 (10 A g-1) and an ultralong cycling performance of 328 mA h g-1 even after 3500 cycles (2 A g-1) as the anode for SIBs.

Novel Biomimetic "Spider Web" Robust, Super-Contractile Liquid Crystal Elastomer Active Yarn Soft Actuator.

In nature, spider web is an interwoven network with high stability and elasticity from silk threads secreted by spider. Inspired by the structure of spider webs, light-driven liquid crystal elastomer (LCE) active yarn is designed with super-contractile and robust weavability. Herein, a novel biomimetic gold nanorods (AuNRs) @LCE yarn soft actuator with hierarchical structure is fabricated by a facile electrospinning and subsequent photocrosslinking strategies. Meanwhile, the inherent mechanism and actuation performances of the as-prepared yarn actuator with interleaving network are systematically analyzed. Results demonstrate that thanks to the unique "like-spider webs" structure between fibers, high molecular orientation within the LCE microfibers and good flexibility, they can generate super actuation strain (≈81%) and stable actuation performances. Importantly, benefit from the robust covalent bonding at the organic-inorganic interface, photopolymerizable AuNRs molecules are uniformly introduced into the polymer backbone of electrospun LCE yarn to achieve tailorable shape-morphing under different light intensity stimulation. As a proof-of-concept illustration, light-driven artificial muscles, micro swimmers, and hemostatic bandages are successfully constructed. The research disclosed herein can offer new insights into continuous production and development of LCE-derived yarn actuator that are of paramount significance for many applications from smart fabrics to flexible wearable devices.

Synergistic effect of stereo-complexation and interfacial compatibility in ammonium polyphosphate grafted polylactic acid fibers for simultaneously improved toughness and flame retardancy.

Flammability and poor toughness of unmodified PLA limit its applications in various fields. Though ammonium polyphosphate (APP) is a green and effective flame retardant, it has poor compatibility with the matrix, leading to a decrease in mechanical properties. Stereo-complexation greatly improves the strength and heat resistance of traditional PLA. However, the effect of flame retardants on the formation of stereo-complexed crystals and the impact of stereo-complexation on flame retardancy have not been studied previously. In this research, PDLA chains were first in-situ reacted with APP particles for improved interfacial compatibility. By utilizing the characteristic of PLA enantiomers that can form stereo-complexed crystals, near-complete stereo-complexed PLA fibers with flame retardancy were produced via clean and continuous melt spinning. The compatibility between PDLA-g-APP and PLLA matrix was studied by SEM, rheological analyses and DSC. Strength and flexibility of the fibers were simultaneously enhanced compared to traditional PLA due to the synergistic effect of interfacial compatibility and stereo-complexation. Compared to traditional PLA, the peak heat release rate and total heat release in microcalorimetry test were reduced by 33 % and 22 %, respectively. The flame-retardant fibers achieved a V-0 rating in the UL-94 test, and an increase in LOI value from 19.4 % to 28.2 %.

Fabrication and Photothermal Actuation Performances of Electrospun Carbon Nanotube/Liquid Crystal Elastomer Blend Yarn Actuators.

Liquid crystal elastomers (LCEs) are a kind of polymer network that combines the entropic elasticity of polymer networks and the mesogenic unit by means of mild cross-linking. LCEs have been extensively investigated in various fields, including artificial muscles, actuators, and microrobots. However, LCEs are characterized by the poor mechanical properties of the light polymers themselves. In this study, we propose to prepare a carbon nanotube/liquid crystal elastomer (CNT/LCE) composite yarn by electrospinning technology and a two-step cross-linking strategy. The CNT/LCE composite yarn exhibits a reversible shrinkage ratio of nearly 70%, a tensile strength of 16.45 MPa, and a relatively sensitive response speed of ∼3 s, enabling a fast response by photothermal actuation. The research disclosed in this article may provide new insights for the development of artificial muscles and next-generation smart robots.

MoNP-doped Defective Carbon Fibers with Bark-like Nanosurface as Effective Bifunctional Electrocatalysts for Zn-air Batteries.

The flexible air electrode with high oxygen electrocatalytic performance and outstanding stability under various deformations plays a vital role in high-performance flexible Zn-air batteries (ZABs). Herein, a self-supported Mo, N, and P co-doped carbon cloth (CC) denoted as MoNP@CC with bark-like surface structure is fabricated by a facile two-step approach via a one-pot method and pyrolysis. The surface of the electrode shows a nanoscale "rift valley" and uniformly distributed active sites. Taking advantage of the nano-surface as well as transition metal and heteroatom doping, the self-supported electrocatalysis air electrode exhibits considerable oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) performance in terms of low overpotential (388 mV at 10 mA cm-2) for OER and a much positive potential (0.74 V) at 1.0 mA cm-2 for ORR. Furthermore, MoNP@CC is further used for the flexible ZAB to demonstrate its practical application. The MoNP@CC-based ZAB displays a good cycling performance for 2800 min and an open-circuit voltage of 1.44 V. This work provides a new approach to the construction of a high-performance, self-supported electrocatalysis electrode used for a flexible energy storage device.

A fast hemostatic and enhanced photodynamic 2-dimensional metal-organic framework loaded aerogel patch for wound management.

Achieving rapid hemostasis and highly effective antibacterial holds significant importance in the early-stage treatment of wounds. In this study, a hybrid aerogel patch comprising carbon quantum dots (CQDs) modified 2-dimensional (2D) porphyrinic metal-organic framework (MOF) nanosheets was designed by incorporating gelatin methacrylate (GelMA) and polyacrylamide (PAM) based matrix. On one hand, CQDs were stably doped onto the surface of the 2D MOF nanosheets, thereby enhancing the photodynamic activity through fluorescence resonance energy transfer (FRET) process. After the preparation of hybrid aerogel patch, the patch loaded with CQDs-doped 2D MOF exhibited excellent photodynamic bactericidal activity against Gram-positive Staphylococcus aureus (>99.99 %) and Gram-negative Escherichia coli (>99.99 %). On the other hand, the hybrid patch with highly porous and absorbent structure can rapidly absorb blood to aggregate clotting components and form a hydration barrier covering the wound to enhance hemostasis. Besides, the hemolysis and cytotoxicity assays demonstrated a good biocompatibility of this designed patch. In summary, this 2D MOF-loaded aerogel patch holds a potential to achieve rapid hemostasis and effective anti-infection in the early-stage treatment of traumatic wounds.

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.

Highly Stretchable and Fluorescent Visualizable Thermoplastic Polyurethane/Tetraphenylethylene Plied Yarn Strain Sensor with Heterogeneous and Cracked Structure for Human Health Monitoring.

Smart wearable technology has been more and more widely used in monitoring and prewarning of human health and safety, while flexible yarn-based strain sensors have attracted extensive research interest due to their ability to withstand greater external strain and their significant application potential in real-time monitoring of human motion and health signals. Although several strain sensors based on yarn structures have been reported, it remains challenging to strike a balance between high sensitivity and wide strain ranges. At the same time, visual signal sensing is expected to be used in strain sensors thanks to its intuitiveness. In this work, thermoplastic polyurethane (TPU) and tetraphenylethylene (TPE) were wet-spun to fabricate flexible fluorescent fibers used as the substrate of the sensor, followed by the drop addition of polydimethylsiloxane (PDMS) beads and curing to produce a heterogeneous structure, which were further twisted into a plied yarn. Finally, a visualizable flexible yarn strain sensor based on solidified liquid beads and crack structure was obtained by loading polydopamine (PDA) and polypyrrole (PPy) in situ. The sensor exhibited high sensitivity (the GF value was 58.9 at the strain range of 143-184%), a wide working strain range (0-184%), a low monitoring limit (<0.1%), a fast response (58.82 ms), reliable responses at different frequencies, and excellent cycle durability (over 2000 cycles). At the same time, the yarn strain sensor also had excellent photothermal characteristics and a fluorescence crack visualization effect. These attractive advantages enabled yarn strain sensors to accurately monitor various human activities, showing great application potential in health monitoring, personalized medical diagnosis, and other aspects.

High Electrochemical Capacity MnO2/Graphene Hybrid Fibers Based on Crystalline Regulatable MnO2 for Wearable Supercapacitors.

Fiber-based supercapacitors (FSCs) exhibit desirable application potential and development prospects in wearable energy storage devices because of their flexibility and wearability. However, the low capacity in the unit volume and insufficient fiber strength hinder their further development in practical application. Herein, the MnO2 nanomaterials with regulatable crystalline structure were synthesized by one-step hydrothermal strategy. The formation of the MnO2 crystalline structure involved the "crimp-phase transition" process. Among them, the 2 × 2 tunnel type α-MnO2 nanowires exhibited excellent electrochemical capacitance (43.8 F g-1), high rate performance (61%, 0.25 to 6 A g-1), and remarkable cyclic stability (99%), which can be attributed to their good symmetry in space and high shared vertices proportion. On this basis, the α-MnO2 nanowires were coblended with GO to construct MnO2/rGO hybrid fibers by scalable continuous wet spinning and in situ acid reduction. Noteworthily, in MnO2/rGO hybrid fibers, the doping amount of MnO2 nanowires as high as 50 wt % could be achieved, while the strength reached 11.73 MPa, which can be ascribed to the superior surface morphology of MnO2 nanowires and the unique cement wall structure of hybrid fibers. Finally, the obtained hybrid fiber electrodes were assembled into symmetrical FSCs. Notably, the FSCs delivered remarkable volume specific capacitance (129.5 F cm-3) and impressive energy density (18 mWh cm-3) at 1.75 A cm-3. In addition, the assembled all-solid-state FSCs indicated excellent deformability and application potential. This work offers some insight for promoting the continuous preparation of fiber electrodes, the development of FSCs, and practical application in wearable energy textile.

Regeneration and modification of cellulose acetate from cigarette waste: Biomedical potential by encapsulation of tetracycline hydrochloride.

Cigarette waste are pervasive litter on Earth, posing a major threat to organisms and ecosystems. However, these waste contain cellulose acetate (CA) and can be recycled, transforming into raw materials for new products. Polymers like CA can be used in biomedical applications as drug carriers and scaffolds for drug release. In this study, cigarette filters waste was collected, recycled and used for fabricating the nanofibrous membrane of cellulose acetate nanofibers (CFCA) through electrospinning technique. Tetracycline hydrochloride (TC) was encapsulated in the nanofibers to prevent bacterial infections. Various analyses were conducted: Scanning Electron Microscope (SEM), Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction Analysis (XRD) and Thermogravimetric analysis (TGA). CA and CFCA exhibited high water uptake properties and exhibited similar breaking stress and strain values. Both CA and CFCA effectively acted as stable drug carriers, with sustained in vitro drug release. Antibacterial activity was demonstrated by the drug-loaded CA and CFCA nanofibers against, Gram-positive bacteria Staphylococcus aureus and Gram-negative bacteria Escherichia coli. Based on their cytotoxicity evaluations on mouse fibroblast cells (L929), CA and CFCA fibrous mats demonstrated no cytotoxicity and similar cell viability results. Consequently, the TC-loaded nanofibers made from CA and CFCA exhibited suitable properties for wound healing applications.

Study on the Construction of Interlayer Adjustable C@MoS2 Fiber Anode by Biomass Confining and its Lithium/Sodium Storage Mechanism.

Building a stable and controllable interlayer structure is the key to improving the sodium storage cycling stability and rate performance of two-dimensional anode materials. This study explored the rich functional groups in bacterial cellulose culture medium in the way of biological self-assembly. Mo precursors were used to produce chemical bond in bacterial cellulose culture medium, and intercalation groups are introduced to achieve MoS2 localized nucleation and in situ localized construction of carbon intercalation stable interlaminar structure, thus improving ion transport dynamics and cycle stability. In order to avoid structural irreversibility of MoS2 at low potential, an extended voltage window of 1.5-4 V was selected for lithium/sodium intercalation testing. It was found that there was a significant improvement in sodium storage capacity and stability. During the electrochemical cycling process, in-situ Raman testing revealed that the structure of MoS2 was completely reversible, and the intensity changes of MoS2 characteristic peaks showed in-plane vibration without involving interlayer bonding fracture. Moreover, after the lithium sodium was removed from the intercalation C@MoS2 all structures have good retention.

Hydrogel transformed from sandcastle-worm-inspired powder for adhering wet adipose surfaces.

Normally, hydrogel adhesives do not perform well on adipose matters that are covered with bodily fluids. Besides, the maintenance of high extensibility and self-healing ability in fully swollen state still remains challenging. Based on these concerns, we reported a sandcastle-worm-inspired powder, which was made of tannic acid-functionalized cellulose nanofiber (TA-CNF), polyacrylic acid (PAA) and polyethyleneimine (PEI). The obtained powder can rapidly absorb diverse bodily fluids and transform into a hydrogel, displaying fast (＜3 s), self-strengthening and repeatable wet adhesion to adipose tissues. Due to the dense physically cross-linked network, the formed hydrogel still showed excellent extensibility (∼14 times) and self-healing ability after being immersed in water. Moreover, excellent hemostasis, antibacterial ability and biocompatibility make it suitable for numerous biomedical applications. With combined advantages of powders and hydrogels, such as good adaptability to irregular sites, efficient drug loading capacity and tissue affinity, the sandcastle-worm-inspired powder offers significant promise as tissue adhesive and repair materials. This work may open new avenues for designing high-performance bioadhesives with efficient and robust wet adhesiveness to adipose tissues.

Scalable functionalized liquid crystal elastomer fiber soft actuators with multi-stimulus responses and photoelectric conversion.

Liquid crystal elastomer (LCE) fibers exhibit large deformation and reversibility, making them an ideal candidate for soft actuators. It is still challenging to develop a scalable strategy and endow fiber actuators with photoelectric functions to achieve tailorable photo-electro-thermal responsiveness and rapid large actuation deformation. Herein, we fabricated a multiresponsive actuator that consists of LCE long fibers obtained by continuous dry spinning and further coated it with polydopamine (PDA)-modified MXene ink. The designed PDA@MXene-integrated LCE fiber is used for shape-deformable and multi-trigger actuators that can be photo- and electro-thermally actuated. The proposed LCE fiber actuator combines an excellent photothermal and long-term electrically conductive PDA@MXene and a shape-morphing LCE fiber, enabling their robust mechanical flexibility, multiple fast responses (∼0.4 s), and stable and large actuation deformation (∼60%). As a proof-of-concept, we present near-infrared light-driven artificial muscle that can lift 1000 times the weight and an intelligent circuit switch with stable controllability and fast responsiveness (∼0.1 s). Importantly, an adaptive smart window system that integrates light-driven energy harvesting/conversion functions is ingeniously constructed by the integration of a propellable curtain woven by the designed fiber and solar cells. This work can provide insights into the development of advanced intelligent materials toward soft robotics, sustainable energy savings and beyond.

Study on the Controllable Preparation of Nd3+ Doped in Fe3O4 Nanoparticles for Magnetic Protective Fabrics.

Magnetic protective fabrics with fine wearability and great protective properties are highly desirable for aerospace, national defense, and wearable protective applications. The study of the controllable preparation method of Nd3+ doped in Fe3O4 nanoparticles with supposed magnetic properties remains a challenge. The characterization of the microstructure, elemental composition, and magnetic properties of NdFe2O4 nanoparticles was verified. Then, the surface of NdFe2O4 was treated with glyceric acid to provide sufficient -OH. Subsequently, the connection of the nanoparticle by the succinimide group was studied and then grafted onto cotton fabrics as its bridging effect. The optimal loading rate of the functional fabrics with nanoparticles of an average size of 230 nm was 1.37% after a 25% alkali pretreatment. The color fatness to rubbing results showed better stability after washing and drying. The corresponding hysteresis loop indicated that the functional fabrics exhibited typical magnetism behavior with a closed "S" shape and a magnetic saturation value of 17.61 emu.g-1 with a particle size of 230 nm. However, the magnetic saturation value of the cotton fabric of 90 nm was just 4.89 emu.g-1, exhibiting controllable preparation for the aimed electromagnetic properties and great potential in radiation protective fields. The electrochemical properties of the functional fabrics exhibited extremely weak electrical conductivity caused by the movement of the magnetic dipole derived from the NdFe2O4 nanoparticles.

Amphiphilic sodium alginate-polylysine hydrogel with high antibacterial efficiency in a wide pH range.

Bacterial infection is a major pathological factor leading to persistent wounds. With the aging of population, wound infection has gradually become a global health-issue. The wound site environment is complicated, and the pH changes dynamically during healing. Therefore, there is an urgent need for new antibacterial materials that can adapt to a wide pH range. To achieve this goal, we developed a thymol-oligomeric tannic acid/amphiphilic sodium alginate-polylysine hydrogel film, which exhibited excellent antibacterial efficacy in the pH range from 4 to 9, achieving the highest achievable 99.993 % (4.2 log units) and 99.62 % (2.4 log units) against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli, respectively. The hydrogel films exhibited excellent cytocompatibility, suggesting that the materials are promising as a novel wound healing material without the concern of biosafety.