Versatile, durable conductive networks assembled from MXene and sericin-modified carbon nanotube on polylactic acid textile micro-etched via deep eutectic solvent.

Integration of polylactic acid (PLA) textiles with conductive MXene holds great promise for fabricating green electronic textiles (e-textiles) and reducing the risk of electronic waste. However, constructing robust conductive networks on PLA fibers remains challenging due to the susceptibility of MXene to oxidation and the hydrophobicity of PLA fibers. Here, we demonstrate a versatile, degradable, and durable e-textile by decorating the deep eutectic solvent (DES) micro-etched PLA textile with MXene and sericin-modified carbon nanotube hybrid (MXene@SSCNT). The co-assembly of MXene with SSCNT in water not only enhanced its oxidative stability but also formed synergistic conductive networks with biomimetic leaf-like nanostructures on PLA fiber. Consequently, the MXene@SSCNT coated PLA textile (MCP-textile) exhibited high electrical conductivity (5.5 Ω·sq-1), high electromagnetic interference (EMI) shielding efficiency (34.20 dB over X-band), excellent electrical heating performance (66.8 ℃, 5 V), and sensitive humidity response. Importantly, the interfacial bonding between the MXene@SSCNT and fibers was significantly enhanced by DES micro-etching, resulting in superior wash durability of MCP-textile. Furthermore, the MCP-textile also showed satisfactory breathability, flame retardancy, and degradability. Given these outstanding features, MCP-textile can serve as a green and versatile e-textile with tremendous potential in EMI shielding, personal thermal management, and respiratory monitoring.

Removal of Tetracycline Hydrochloride by Photocatalysis Using Electrospun PAN Nanofibrous Membranes Coated with g-C3N4/Ti3C2/Ag3PO4.

In order to improve the photocatalytic performance of g-C3N4, the g-C3N4/Ti3C2/Ag3PO4 S-type heterojunction catalyst was prepared by electrostatic assembly method, and then the g-C3N4/Ti3C2/Ag3PO4/PAN composite nanofiber membrane was prepared by electrospinning technology. The morphology and chemical properties of the nanofiber membrane were characterized by SEM, FTIR, and XRD, and the photocatalytic degradation of tetracycline hydrochloride (TC) in water by the nanofiber membrane was investigated. The results showed that g-C3N4/Ti3C2/Ag3PO4 could be successfully loaded on PAN and uniformly distributed on the surface of composite nanofiber membrane by electrospinning technology. Increasing the amount of loading and catalyst, lowering the pH value and TC concentration of the system were conducive to the oxidation and degradation of TC. The nano-fiber catalytic membrane had been recycled five times and found to have excellent photocatalytic stability and reusability. The study of catalytic mechanism showed that h+, •OH and •O2- were produced and participated in the oxidation degradation reaction of TC, and •O2- plays a major role in catalysis. Therefore, this work provides a new insight into the construction of high-performance and high-stability photocatalytic system by electrospinning technology.

Superelastic and multifunctional fibroin aerogels from multiscale silk micro-nanofibrils exfoliated via deep eutectic solvent.

Superelastic silk fibroin (SF)-based aerogels can be used as multifunctional substrates, exhibiting a promising prospect in air filtration, thermal insulation, and biomedical materials. However, fabrication of the superelastic pure SF aerogels without adding synthetic polymers remains challenging. Here, the SF micro-nano fibrils (SMNFs) that preserved mesostructures are extracted from SF fibers as building blocks of aerogels by a controllable deep eutectic solvent liquid exfoliation technique. SMNFs can assemble into multiscale fibril networks during the freeze-inducing process, resulting in all-natural SMNF aerogels (SMNFAs) with hierarchical cellular architectures after lyophilization. Benefiting from these structural features, the SMNFAs demonstrate desirable properties including ultra-low density (as low as 4.71 mg/cm3) and superelasticity (over 85 % stress retention after 100 compression cycles at 60 % strain). Furthermore, the potential applications of superelastic SMNFAs in air purification and thermal insulation are investigated to exhibit their functionality, mechanical elasticity, and structural stability. This work provides a reliable approach for the fabrication of highly elastic SF aerogels and endows application prospects in air purification and thermal insulation opportunities.

Enhancing the solubility and antimicrobial activity of cellulose through esterification modification using amino acid hydrochlorides.

Most amino acid molecules have good water solubility and are rich in functional groups, which makes them a promising derivatizing agent for cellulose. However, self-condensation of amino acids and low reaction efficiency always happen during esterification. Here, amino acid hydrochloride ([AA]Cl) is selected as raw material to synthesize cellulose amino acid ester (CAE). Based on TG-MS coupling technology, a significantly faster reaction rate of [AA]Cl compared to raw amino acid can be observed visually. CAE with the degree of substitution 0.412-0.516 is facilely synthesized under 130-170 °C for 10-50 min. Moreover, the effects of amounts of [AA]Cl agent, temperature, and time on the esterification are studied. The CAE can be well dissolved in 7 wt% NaOH aq., resulting in a 7.5 wt% dope. The rheological test of the dope demonstrated a shear-thinning behavior for Newtonian-like fluid, and a high gel temperature (41.7 °C). Further, the synthesized products show distinct antibacterial activity and the bacteriostatic reduction rate against E. coli can reach 99.5 %.

Interfused core-shell heterogeneous graphene/MXene fiber aerogel for high-performance and durable electromagnetic interference shielding.

Flexible, lightweight, and durable electromagnetic interference (EMI) shielding materials are urgently required to solve the increasingly serious electromagnetic radiation pollution. Transition metal carbides/nitrides (MXenes) are promising candidates for EMI shielding materials because of their excellent metallic electrical conductivity. However, MXenes are highly susceptible to oxidization when exposed to wet environments, leading to the loss of their functional properties and degradation of reliability and stability. Herein, an interfused core-shell heterogeneous reduced graphene oxide (rGO)/MXene aerogel (GMA) is designed for the first time via coaxial wet spinning and freeze-drying. The fabricated GMAs exhibit excellent EMI shielding performance, and the EMI shielding effectiveness (SE) and specific EMI SE can be up to 83.3 dB and 3119 dB·cm3/g, respectively, which is higher than most carbon-based and MXene-based aerogels and foams. More importantly, GMAs have only a 17.4 % degradation in EMI shielding performance after 120 days due to the protection of hydrophobic graphene sheath, exhibiting superior EMI shielding durability to its MXene film counterpart. Moreover, the hydrophobic GMAs exhibit good oil/water separation and thermal insulation performance. The interfused core-shell GMAs are highly promising for applications in durable EMI shielding, thermal insulation, oil/water separation and sensors, etc.

Durable antibacterial cotton fabric fabricated using a "self-created" mist polymerization device.

There are two major problems associated with the use of antibacterial cotton fabric. The durability of the fabric is poor, and the inherent properties of the fabric deteriorate following the execution of the finishing processes. These limit the application of antibacterial fabric. We first treated the cotton fabric with acryloyl chloride (AC) molecules to make the surface of the fabric rich in carbon­carbon double (C=C) bonds. Following this, the [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide (DMES) monomer was polymerized with the CC bonds on the fabric following the "grafting through" method. As a result, the cotton fabric was successfully grafted with the poly[2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide (PDMES), exploiting covalent bonds. The finished fabric exhibited excellent antibacterial effects. The bacterial reduction (BR) rates of the finished fabric against E. coli and S. aureus were greater than 99.0 %. Even after 50 washing cycles, the BR rates of the finished fabric against E. coli and S. aureus were greater than 96.0 %. In addition, the use of the "self-created" mist polymerization technology ensured that the inherent properties of the finished fabric were retained to a large extent. Therefore, the antibacterial cotton fabric prepared following this method can be potentially used for the fabrication of industrial and household textiles.

Centrifugal Spinning Enables the Formation of Silver Microfibers with Nanostructures.

Silver nanowires (AgNWs) have received much attention and application in transparent electrodes, wearable electronic devices, and sensors. The hope is for these nanowires to eventually replace the most commonly used transparent electrode material-indium tin oxide (ITO). However, electrospinning used for the preparation of AgNWs on a large scale is limited by its low productivity and high electric field, while the alcohol-thermal method is limited to mixing by-product silver nanoparticles in silver nanowires. We demonstrate a novel and simple centrifugal spinning approach in order to successfully fabricate ultra-long silver microfibers based on AgNO3 and polyvinyl pyrrolidone (PVP). The centrifugal-spun precursor fiber and silver fiber can be prepared to as thin as 390 and 310 nm, respectively. Annealed fibers show typical nanostructures with grains down to a minimum size of 51 nm. Combinations of different parameters, including concentrations of PVP, needle size, and annealing temperature are also investigated, in order to optimize the spinning process of ultra-long silver microfibers. The feasibility of preparing silver microfibers by centrifugal spinning is preliminarily verified, examining prospects for mass production. Furthermore, numerous strategies related to assisting the creation of silver nanofibers using centrifugal spinning are presented as possibilities in future development.

Roll-to-roll layer-by-layer assembly bark-shaped carbon nanotube/Ti3C2Tx MXene textiles for wearable electronics.

Smart wearable electronics have drawn increasing attention for their potential applications in personal thermal management, human health monitoring, portable energy conversion/storage, electronic skin and so on. However, it is still a critical challenge to fabricate the multifunctional textiles with tunable morphology and performance while performing well in flexibility, air permeability, wearing comfortability. Herein, we develop a novel roll-to-roll layer-by-layer assembly strategy to construct bark-shaped carbon nanotube (CNT)/Ti3C2Tx MXene composite film on the fiber surface. The fabricated bark-shaped CNT/MXene decorated fabrics (CMFs) exhibit good flexibility, air permeability and electrical conductivity (sheet resistance, 6.6 Ω/□). In addition, the CMFs demonstrate good electrothermal performance (70.9 °C, 5 V), electromagnetic interference (EMI) shielding performance (EMI shielding effectiveness, 30.0 dB under X-Brand), and high sensitivity as the flexible piezoresistive sensors for monitoring the human motions. Importantly, our CMFs show distinctive EMI shielding mechanism, where a great proportion of incident electromagnetic microwaves are reflected by the bark-shaped CNT/MXene films owing to the multi-interface scattering effects. This work may provide a new strategy for the fabrication of multifunctional textile-based electronics and pave the way for smart wearable electronics.

Vapor phase polymerized conducting polymer/MXene textiles for wearable electronics.

Multifunctional electronic textiles hold great potential applications in the wearable electronics field. However, it remains challenging to seamlessly integrate the multiple functions on the textile substrates without sacrificing their intrinsic properties. Herein, we report a novel and facile vapor phase polymerization (VPP) and spray-coating strategy towards the construction of a laminated film containing a PEDOT film and Ti3C2Tx MXene sheets on the fiber surface. The fabricated PEDOT/MXene decorated cotton fabrics are integrated with excellent electrochemical performance, joule heating performance, good electromagnetic interference (EMI) shielding, and strain sensing performance. The resultant multifunctional textiles have a low sheet resistance of 3.6 Ω sq-1, and the assembled all-solid-state fabric supercapacitors exhibit an ultrahigh specific capacitance of 1000.2 mF cm-2, which exceeds the state-of-the-art MXene-based fabric supercapacitors. In addition, the PEDOT/MXene modified fabrics exhibit an exceptional joule heating performance of 193.1 °C at the applied voltage of 12 V, high EMI shielding effectiveness of 36.62 dB, and high sensitivity as strain sensors for human motion detection. This work provides a novel strategy for the structure design of multifunctional textiles and will lay the foundation for the development of multifunctional wearable electronics.

Treatment with catalpol protects against cisplatin-induced renal injury through Nrf2 and NF-κB signaling pathways.

Cisplatin (CP) is one of the most widely used chemotherapy drugs for cancer treatment, but it often leads to nephrotoxicity. It is well known that catalpol exhibits antioxidant and anti-inflammatory functions, thus the present study aimed to investigate the potential protective effects of catalpol on CP-induced kidney injury in rats, in addition to determining the underlying mechanisms. Sprague-Dawley rats were treated with 25, 50 or 100 mg/kg catalpol for two days, injected with 20 mg/kg cisplatin and catalpol on day 3 and sacrificed on day 4. The histological analysis of isolated kidney tissues was performed using hematoxylin and eosin staining, cleaved caspase-3 expression levels were analyzed using western blotting and the expression levels of inflammatory cytokines in the tissues, including tumor necrosis factor α (TNF-α), interleukin (IL)-1ß, IL-6, IL-8, IL-10 and inducible nitric oxide synthase (iNOS) were evaluated using ELISAs. Furthermore, the mRNA and protein expression levels of nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase 1 (HO-1), kelch-like ECH-associated protein 1 (Keap1), NF-κB and inhibitory κB (IκB) were determined using reverse transcription-quantitative PCR and western blotting, respectively. The results revealed that the treatment with catalpol prevented the histopathological injury and renal dysfunction caused by CP. In addition, catalpol significantly suppressed the CP-induced apoptosis of tubular cells, inhibited the CP-induced upregulation of TNF-α, IL-1ß, IL-6, IL-8 and iNOS and promoted the production of the anti-inflammatory cytokine IL-10. Additionally, the mRNA and protein expression levels of Nrf2, HO-1 and IκB in the kidney tissues were increased, whereas the expression levels of Keap1 and NF-κB were significantly decreased following the treatment with catalpol. In conclusion, these results suggested that catalpol may inhibit CP-induced renal injury and suppress the associated inflammatory response through activating the Nrf2 and inhibiting the NF-κB signaling pathways, respectively.

Highly effective antibacterial zeolitic imidazolate framework-67/alginate fibers.

Antibacterial fibers have great potential in many applications including wound dressings, surgical gowns, and surgical sutures, and play an important role in our daily life. However, the traditional fabrication method for the antibacterial fibers shows high cost, complexity, and inferior antibacterial durability. Herein, we report a facile and scalable fabrication of highly effective antibacterial alginate (SA) composite fibers through blend spinning of zeolitic imidazolate framework-67 (ZIF-67) particles and SA. The fabricated ZIF-67@SA composite fibers show high tensile strength and initial modulus. More importantly, the ZIF-67@SA composite fibers demonstrate excellent antibacterial properties, and the antibacterial efficiency reaches over 99% at ultralow ZIF-67 loading (0.05 wt%). In addition, the ZIF-67@SA fibers show good antibacterial durability even after five laundering cycles. The excellent antibacterial performance of the ZIF-67@SA fibers is attributed to the synergistic effects of the highly effective antibacterial ZIF-67 particles, swelling of alginate, and immobilization of ZIF-67 particles both inside and outside the fiber surface. This work may shed light on the antibacterial mechanism of metal organic frameworks and pave the way for the development of high-performance antibacterial textiles.

Robust ZIF-8/alginate fibers for the durable and highly effective antibacterial textiles.

Antibacterial fibers have great potential in many applications, such as medical dressings, surgical sutures and masks, etc. owing to their good growth inhibition against bacteria. However, for the fabrication of antibacterial fibers, the traditional inorganic nanoparticles coating method shows the disadvantages of high cost, low stability and binding fastness. Herein, we develop a facile, scalable and cost-effective blend spinning strategy to fabricate the highly effective antibacterial zeolitic imidazolate framework-8@alginate (ZIF-8@SA) fibers through wet spinning of the mixture of ZIF-8 and SA. The fabricated ZIF-8@SA fibers show high antibacterial efficiency, good durability and high tensile strength. The antibacterial performance of ZIF-8@SA fibers is superior to the most reported inorganic nanoparticles modified fibers. The excellent antibacterial performance of ZIF-8@SA fibers is attributed to the reactive oxygen species from the ZIF-8 and the swelling of SA. This work may shed light on the antibacterial mechanisms of metal organic frameworks and pave the way for the development of high-performance, durable and highly effective antibacterial textiles.

Robust Silk Fibroin/Graphene Oxide Aerogel Fiber for Radiative Heating Textiles.

Aerogel fibers with ultrahigh porosity and ultralow density are promising candidates for personal thermal management to reduce the energy waste of heating an entire room, and play important roles in reducing energy waste in general. However, aerogel fibers generally suffer from poor mechanical properties and complicated preparation processes. Herein, we demonstrate hierarchically porous and continuous silk fibroin/graphene oxide aerogel fibers (SF/GO) with high strength, excellent radiative heating performance, and thermal insulation performance through coaxial wet spinning and freeze-drying. The hollow CA/PAA fibers prepared via a coaxial wet spinning process have multiscale porous structures, which are not only beneficial for the formation of an SF/GO aerogel core, but also help to improve the mechanical strength of the aerogel fibers. Moreover, the prepared aerogel fibers show comparable porosity and mechanical properties with those of hollow CA/PAA fibers. More importantly, GO can dramatically improve the infrared radiative heating properties, and the surface temperature is increased by 2.6 °C after exposure to infrared radiation for 30 s, greatly higher than that of hollow fiber and SF aerogel fibers. Furthermore, the integration of hierarchically porous hollow fibers and SF/GO aerogels prevents thermal convection, decreases thermal conduction, and suppresses thermal radiation, rendering the SF/GO aerogel fiber with excellent thermal insulation performance. This work may shed light on the heat transfer mechanism of the microenvironment between the human body and textiles and pave the way for the fabrication of high-performance aerogel fibers used for personal thermal management.

Continuous, Strong, Porous Silk Firoin-Based Aerogel Fibers toward Textile Thermal Insulation.

Aerogel fiber, with the characteristics of ultra-low density, ultra-high porosity, and high specific surface area, is the most potential candidate for manufacturing wearable thermal insulation material. However, aerogel fibers generally show weak mechanical properties and complex preparation processes. Herein, through firstly preparing a cellulose acetate/polyacrylic acid (CA/PAA) hollow fiber using coaxial wet-spinning followed by injecting the silk fibroin (SF) solution into the hollow fiber, the CA/PAA-wrapped SF aerogel fibers toward textile thermal insulation were successfully constructed after freeze-drying. The sheath (CA/PAA hollow fiber) possesses a multiscale porous structure, including micropores (11.37 ± 4.01 µm), sub-micron pores (217.47 ± 46.16 nm), as well as nanopores on the inner (44.00 ± 21.65 nm) and outer (36.43 ± 17.55 nm) surfaces, which is crucial to the formation of a SF aerogel core. Furthermore, the porous CA/PAA-wrapped SF aerogel fibers have many advantages, such as low density (0.21 g/cm3), high porosity (86%), high strength at break (2.6 ± 0.4 MPa), as well as potential continuous and large-scale production. The delicate structure of multiscale porous sheath and ultra-low-density SF aerogel core synergistically inhibit air circulation and limit convective heat transfer. Meanwhile, the high porosity of aerogel fibers weakens heat transfer and the SF aerogel cellular walls prevent infrared radiation. The results show that the mat composed of these aerogel fibers exhibits excellent thermal insulating properties with a wide working temperature from -20 to 100 °C. Therefore, this SF-based aerogel fiber can be considered as a practical option for high performance thermal insulation.

Electrospun Jets Number and Nanofiber Morphology Effected by Voltage Value: Numerical Simulation and Experimental Verification.

Electrical voltage has a crucial effect on the nanofiber morphology as well as the jet number in the electrospinning process, while few literatures were found to explain the deep mechanism. Herein, the electrical field distribution around the spinning electrode was studied by the numerical simulation firstly. The results show that the electrical field concentrates on the tip of a protruding droplet under relatively low voltage, while subsequently turns to the edge of needle tip when the protruding droplet disappears under high voltage. The experimental results are well consistent with the numerically simulated results, that is, only one jet forms at low voltage (below 20 kV for PVDF-HFP and PVA nanofiber), but more than one jet forms under high voltage (two jets for PVDF-HFP nanofiber, four jets for PVA nanofiber). These more jets lead to (1) higher fiber diameter resulting from actually weaker electrical field for each jet and (2) wide distribution of fiber diameters due to unstable spinning process (changeable jet number/site/height) under high voltage. The results will benefit the nanofiber preparation and application in traditional single-needle electrospinning and other electrospinning methods.

One-Step Quaternization/Hydroxypropylsulfonation to Improve Paste Stability, Adhesion, and Film Properties of Oxidized Starch.

To investigate the influences of quaternization/hydroxypropylsulfonation on viscosity stability, adhesion to fibers and film properties of oxidized tapioca starch (OTS) for ameliorating its end-use ability in applications such as warp-sizing and paper-making, a series of quaternized and hydroxypropylsulfonated OTS (QHOTS) samples were synthesized by simultaneous quaternization and hydroxypropylsulfonation of OTS with N-(3-chloro-2-hydroxypropyl) trimethylammonium chloride (CHPTAC) and 3-chloro-2-hydroxy-1-propanesulfonic acid sodium salt (CHPS-Na). The QHOTS granules were characterized by Fourier transform infra-red spectroscopic and scanning electron microscope techniques. Apparent viscosity and viscosity stability were determined, and adhesion was evaluated by measuring the bonding force of starch to the fibers. Film properties were also estimated in terms of tensile strength, breaking elongation, bending endurance, degree of crystallinity, and moisture regain. It was showed that quaternization/hydroxypropylsulfonation was capable of obviously improving viscosity stability of gelatinized OTS paste, enhancing bonding forces of OTS to cotton and polylactic acid (PLA) fibers, increasing breaking elongation, bending endurance and moisture regain of film and decreasing its tensile strength and degree of crystallinity, thereby obviously stabilizing paste viscosity, improving adhesion to fibers and lessening film brittleness. Increasing the level of quaternization/hydroxypropylsulfonation favored improvement in the stability, enhancement in adhesion and decrease in brittleness. The QHOTS showed potential in the applications of cotton and PLA sizing.

[Influence of hypoxia caused by impairment of peritubular capillary on the progression of chronic aristolochic acid nephropathy].

OBJECTIVE: To investigate the manifestation of impairment of peritubular capillary (PTC) in chronic aristolochic acid nephropathy (CAAN) and the influence of hypoxia caused by PTC impairment on the progression of CAAN. METHODS: Fifty-four Wistar rats were randomly divided into 2 groups: Group A (n = 30, perfused intragastrically with decoction of Caulis aristolochia manchuriensis for 8 weeks) and Group B (n = 24, perfused intragastrically with drinking water for 8 weeks). At weeks 8, 12, and 16 ten rats in Group A and 8 rats in Group B were killed. Specimens of blood and urine were collected before the killing of the rats to detect the blood urea nitrogen (BUN), serum creatinine (Scr), and urine protein. HE and Masson staining and microscopy were used to observe the pathology of the kidney. Immunohistochemistry and Western blotting were used to detect the expression of hypoxia-inducible factor-1alpha (HIF-1alpha), vascular endothelial growth factor (VEGF), and CD34. Correlation analysis was conducted to study the relationships among these indices. RESULTS: Since week 8 BUN, Scr, and urine protein of Group A began to increase in comparison with Group B (all P < 0.05). Pathological changes of the kidney began to appear in Group A since week 8 with the decrease of PTC density. HIF-1alpha was not expressed in Group B, and in Group A HIF-1alpha expression began to increase since week 8 and became significantly higher than that of Group B since week 12. At week 16, the PTC density and VEGF-IOD of Group A were 8.10 +/- 2.28/0.13 mm(2) and (2.78 +/- 0.78) x 10(3) respectively, both significantly lower than those of Group B [(42.80 +/- 4.49)/0.13 mm(2) and (26.49 +/- 9.34) x 10(3) respectively, both P < 0.01], and the HIF-1alpha-IOD of Group A was (7.11 +/- 1.20) x 10(3), significantly higher than that of Group B [(0.44 +/- 0.10) x 10(3), P < 0.01]. CD34 was highly expressed in Group B, and the CD34 expression of Group A began to decrease since week 16. HIF-1alpha expression was positively correlated with Scr (r = -0.945, P < 0/01), and PTC density and VEGF expression were negatively correlated with Scr (r = -0.907, P < 0.01 and r = -0.690, P < 0.01). PTC density was negatively correlated with HIF-1alpha expression (r = -0.880, P < 0.01). CONCLUSION: Severe hypoxia exists following PTC injury in CAAN. Hypoxia is correlated with the progression of CAAN.