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Biodegradable polylactic acid (PLA) melt-blown nonwovens are attractive candidates to replace non-degradable polypropylene melt-blown nonwovens. However, it is still an extremely challenging task to prepare PLA melt-blown nonwovens with sufficient mechanical properties for practical application. Herein, we report a simple strategy for the large-scale preparation of biodegradable PLA/poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) melt-blown nonwovens with high strength and excellent toughness. In this process, a small amount of PHBV is added to PLA to improve the latter’s crystallization rate and crystallinity. In addition, when the PHBV content increases from 0 to 7.5 wt%, the diameters of the PLA/PHBV melt-blown fibers decrease significantly (with the proportion of nanofibers increasing from 7.7% to 42.9%). The resultant PLA/PHBV (5 wt% PHBV) melt-blown nonwovens exhibit the highest mechanical properties. The tensile stress, elongation, and toughness of PLA/PHBV (5 wt% PHBV) melt-blown nonwovens reach 2.5 MPa, 45%, and 1.0 MJ·m−3, respectively. More importantly, PLA/PHBV melt-blown nonwovens can be completely degraded into carbon dioxide and water after four months in the soil, making them environmentally friendly. A general tensile-failure model of melt-blown nonwovens is proposed in this study, which may shed light on mechanical performance enhancement for nonwovens.

The rapid development of the global economy and population growth are accompanied by the production of numerous waste textiles. This leads to a waste of limited resources and serious environmental pollution problems caused by improper disposal. The rational recycling of wasted textiles and their transformation into high-value-added emerging products, such as smart wearable devices, is fascinating. Here, we propose a novel roadmap for turning waste cotton fabrics into three-dimensional elastic fiber-based thermoelectric aerogels by a one-step lyophilization process with decoupled self-powered temperature–compression strain dual-parameter sensing properties. The thermoelectric aerogel exhibits a fast compression response time of 0.2 s, a relatively high Seebeck coefficient of 43 μV·K−1, and an ultralow thermal conductivity of less than 0.04 W·m−1·K−1. The cross-linking of trimethoxy(methyl)silane (MTMS) and cellulose endowed the aerogel with excellent elasticity, allowing it to be used as a compressive strain sensor for guessing games and facial expression recognition. In addition, based on the thermoelectric effect, the aerogel can perform temperature detection and differentiation in self-powered mode with the output thermal voltage as the stimulus signal. Furthermore, the wearable system, prepared by connecting the aerogel-prepared array device with a wireless transmission module, allows for temperature alerts in a mobile phone application without signal interference due to the compressive strains generated during gripping. Hence, our strategy is significant for reducing global environmental pollution and provides a revelatory path for transforming waste textiles into high-value-added smart wearable devices.

Abstract Incorporating passive heating structures into personal thermal management technologies could effectively mitigate the escalating energy crisis. However, current passive heating materials struggle to balance thickness and insulating capability, resulting in compromised comfort, space efficiency, and limited thermoregulatory performance. Here, a dual air-gelation strategy, is developed to directly synthesize ultrathin and self-sustainable heating metafabric with 3D dual-network structure during electrospinning. Controlling the interactions among polymer, solvent, and water enables the microphase separation of charged jets, while adjusting the distribution of carbon black nanoparticles within charged fluids to form fibrous networks composed of interlaced aerogel micro/nanofibers with heat storage capabilities. With a low thickness of 0.18 mm, the integrated metafabric exhibits exceptional thermal insulation performance (15.8 mW m−1K−1), superhydrophobicity, enhanced mechanical properties, and high breathability while maintaining self-sustainable radiative heating ability (long-lasting warming of 8.8 °C). This strategy provides rich possibilities to develop advanced fibrous materials for smart textiles and thermal management.

Abstract Electrospun nanofibrous membranes have attracted significant interest due to their captivating waterproof and breathable characteristics, stemming from the presence of interconnected and hydrophobic channels within these enhanced textiles. These distinctive traits bestow upon them substantial potential across various domains, encompassing applications in medical dressings, masks, and protective clothing. However, they also give rise to concerns about their durability, compromised waterproofing performance, limited breathability, insufficient mechanical strength, and high production costs. Furthermore, the manufacturing processes of electrospun waterproof and breathable membranes (WBMs) may carry adverse environmental implications, necessitating improvements in sustainability and ecological compatibility. This study begins with a concise overview of the operational principles and criteria for performance evaluation relevant to electrospun WBMs, providing comprehensive guidelines to drive future research. Following this, the authors delve into a thorough exploration of typical fabrication techniques and the prevailing strategies, exemplified by noteworthy ongoing research initiatives. Last, the existing challenges are outlined to foster the development of WBMs. In addition, future research directions and perspectives are presented to expedite the advancement of WBMs and support their commercial implementation. It is anticipated that this comprehensive review will offer pragmatic recommendations for researchers dedicated to the advancement of WBMs.

Flexible thermoelectric materials play an important role in smart wearables, such as wearable power generation, self-powered sensing, and personal thermal management. However, with the rapid development of Internet of Things (IoT) and artificial intelligence (AI), higher standards for comfort, multifunctionality, and sustainable operation of wearable electronics have been proposed, and it remains challenging to meet all the requirements of currently reported thermoelectric devices. Herein, we present a multifunctional, wearable, and wireless sensing system based on a thermoelectric knitted fabric with over 600 mm·s−1 air permeability and a stretchability of 120%. The device coupled with a wireless transmission system realizes self-powered monitoring of human respiration through an mobile phone application (APP). Furthermore, an integrated thermoelectric system was designed to combine photothermal conversion and passive radiative cooling, enabling the characteristics of being powered by solar-driven in-plane temperature differences and monitoring outdoor sunlight intensity through the APP. Additionally, we decoupled the complex signals of resistance and thermal voltage during deformation under solar irradiation based on the anisotropy of the knitted fabrics to enable the device to monitor and optimize the outdoor physical activity of the athlete via the APP. This novel thermoelectric fabric-based wearable and wireless sensing platform has promising applications in next-generation smart textiles.

Abstract Ceramic aerogels are often used when thermal insulation materials are desired; however, they are still plagued by poor mechanical stability under thermal shock. Here, inspired by the dactyl clubs of mantis shrimp found in nature, which form by directed assembly into hierarchical, chiral and Bouligand (twisted plywood) structure exhibiting superior mechanical properties, we present a compositional and structural engineering strategy to develop strong, superelastic and fatigue resistance ceramic aerogels with chiral fibers array resembling Bouligand architecture. Benefiting from the stress dissipation, crack torsion and mechanical reinforcement of micro-/nano-scale Bouligand array, the tensile strength of these aerogels (170.38 MPa) is between one and two orders of magnitude greater than that of state-of-the-art nanofibrous aerogels. In addition, the developed aerogels feature low density and thermal conductivity, good compressive properties with rapid recovery from 80 % strain, and thermal stability up to 1200 °C, making them ideal for thermal insulation applications.

Highlights Temperature-responsive transparent nanofiber membranes were successfully fabricated using a straightforward and widely applicable method. The temperature-responsive nanofiber membranes exhibit a lower reaction temperature (~ 37 °C) and higher transmittance (> 90%). The prepared temperature-responsive transparent nanofiber membranes exhibited a short response temperature time (~ 5 s), and remarkable stability

People could potentially mitigate heat discomfort when outdoors by combining passive radiative cooling (PRC) strategies with personal thermal management techniques. However, most current PRC materials lack wearing comfort and durability. In this study, a microarray technique is applied to fabricate the tailoring photonic-engineered textiles with intriguing PRC capability and appealing wearability. The developed radiative cooling textiles (RCTs) demonstrate appropriate air–moisture permeability, structural stability, and extended spectroscopic response with high sunlight reflectivity (91.7%) and robust heat emissivity (95.8%) through the atmospheric transparent spectral window (ATSW). In a hot outdoor cooling test, a skin simulator covered by the RCTs displays a temperature drop of approximately 4.4 °C at noon compared with cotton textiles. The evolution of our mimetic structures may provide new insights into the generation of wearable, thermal–wet comfortable, and robust textiles for exploring PRC techniques in personal thermal management applications.

Abstract Background Hot flashes are the common and debilitating symptom among prostate cancer (PCa) patients undergoing androgen deprivation therapy (ADT). Strong evidence from multiple rigorously designed studies indicated that pharmacological option such as venlafaxine provides partial relief, but the tolerability is poor when dose is not tapered. Hence, alternative therapy is needed. Previous studies reported that acupuncture may be helpful in the management of hot flashes. However, the insufficient randomized controlled trial limited the quality of evidence. Methods Five hospitals will recruit 120 acupuncture naïve patients with moderate-to-severe hot flashes after prostate cancer received ADT in China from February 2023 to December 2024. Participants will be randomly 2:1:1 allocated to the 18 sessions of verum acupuncture at true acupuncture points plus usual care, 18 sessions of non-penetrating sham acupuncture at non-acupuncture points plus usual care, or usual care alone over 6 weeks. The primary outcome measure is the change of mean weekly hot flashes symptom severity score (HFSSS) at the end of treatment compared with baseline. Expected Results and Conclusion We will be able to measure the effectiveness of acupuncture for patients with PCa suffering from ADT-induced hot flashes and whether acupuncture is superior to sham acupuncture and usual care. The proposed acupuncture treatment might provide an alternative option for those patients. Trial Registration Clinicaltrials.gov (NCT05069467).

Abstract Thermoelectric sensors have attracted increasing attention in smart wearables due to the recognition of multiple signals in self‐powered mode. However, present thermoelectric devices show disadvantages of low durability, weak wearability, and complex preparation processes and are susceptible to moisture in the microenvironment of the human body, which hinders their further application in wearable electronics. Herein, we prepared a new thermoelectric fabric with thermoplastic polyurethane/carbon nanotubes (TPU/CNTs) by combining vacuum filtration and electrospraying techniques. Electrospraying TPU microsphere coating with good biocompatibility and environmental friendliness made the fabric worn directly and exhibits preferred water resistance, mechanical durability, and stability even after being bent 4000 times, stretched 1000 times, and washed 1000 times. Moreover, this fabric showed a Seebeck coefficient of 49 μV K−1 and strain range of 250% and could collect signals well and avoided interference from moisture. Based on the biocompatibility and safety of the fabric, it can be fabricated into devices and mounted on the human face and elbow for long‐term and continuous collection of data on the body's motion and breathing simultaneously to provide collaborative support information. This thermoelectric fabric‐based sensor will show great potential in advanced smart wearables for health monitoring, motion detection, and human–computer interaction.

While the interlaminar hybrid composites have been used widely and still remain in great demands, interlayer delamination, undesirable in most cases, keeps a common defect, due to the lack of interlaminar fiber-connection. Here, on the basis of the yarn interlacing rule in three-dimensional (3D) four-step braiding technology, 3D braided carbon fibers/Kevlar fibers sandwich (S_) hybrid composites with different braiding angles (S_20°, S_30° and S_40°) have been designed and fabricated with interlaminar fiber-connection. Short-beam shear tests were applied to evaluate the interlaminar shear performances of specimens. The in-situ strain maps during tests were characterized by digital image correlation (DIC) technique and specimen damages were observed via scanning electron microscope (SEM) and computed tomography (CT). Results showed that, comparing to the conventional co-cured laminated hybrid composites, 3D braided sandwich hybrid composites resisted the delamination effectively by the fiber-connection hybrid region. Braiding angle effect of 3D braided sandwich hybrid composites revealed that S_20° showed better deformability and higher structural toughness than their counterparts in S_30° and S_40°. The results presented in the current work would be helpful for the design and manufacturing of well structured hybrid preforms and composites with dramatically improved interlaminar shear properties.

Abstract Chemical warfare agents (CWAs) significantly threaten human peace and global security. Most personal protective equipment (PPE) deployed to prevent exposure to CWAs is generally devoid of self-detoxifying activity. Here we report the spatial rearrangement of metal-organic frameworks (MOFs) into superelastic lamellar-structured aerogels based on a ceramic network-assisted interfacial engineering protocol. The optimized aerogels exhibit efficient adsorption and decomposition performance against CWAs either in liquid or aerosol forms (half-life of 5.29 min, dynamic breakthrough extent of 400 L g−1) due to the preserved MOF structure, van-der-Waals barrier channels, minimized diffusion resistance (~41% reduction), and stability over a thousand compressions. The successful construction of the attractive materials offers fascinating perspectives on the development of field-deployable, real-time detoxifying, and structurally adaptable PPE that could be served as outdoor emergency life-saving devices against CWAs threats. This work also provides a guiding toolbox for incorporating other critical adsorbents into the accessible 3D matrix with enhanced gas transport properties.

Highlights The super-elastic and robust MXene aerogels are created herein by assembling the 1D fibrous MXenes with sufficiently large aspect ratios and superior flexibility. The underlying regulatory mechanism and a complete diagram for the pore structure evolution of MXene aerogels are revealed for the first time, which are particularly instructive for future structure-specific designs. Fibrous MXene aerogels exhibit 8.3% plastic deformation at the 1000th compressions and achieve high evaporation rate (1.48 kg m−2 h−1) and light to thermal conversion efficiency (92.08%) on oil-contaminated seawater.

There is a great demand for transparent films, membranes, or substrates in the fields of intelligent wearables, electronic skins, air filtration, and tissue engineering. Traditional materials such as glass and plastics cannot satisfy these requirements because of the lack of interconnected pores, undesirable porosity, and flexibility. Electrospun fibrous membranes offset these shortcomings because they contain small pores and have high porosity as well as outstanding flexibility. Thus, the development of transparent electrospun fibrous membranes is of great value. This work reports a simple and effective way to develop flexible and porous transparent fibrous membranes (TFMs) directly from electrospun fibrous membranes via mechanical pressing, without employing any other additives. In addition, the relationship between the transparency performance and the molecular structure of the polymers after pressing was summarized for the first time. After mechanical pressing, the membranes maintained fibrous morphology, micron-sized pores, and desired porosity. Polystyrene fibrous membranes, which exhibited excellent optical and mechanical properties, were used as a reference. The TFMs possessed high transparency (~89% visible light transmittance at 550 nm), high porosity (10%–30%), and strong mechanical tensile strength (~148 MPa), nearly 78 times that of the pristine electrospun fibrous membranes. Moreover, this study demonstrated that transparent and conductive membranes can be fabricated based on TFMs using vacuum-assisted filtration of silver nanowires followed by mechanical pressing. Compared with indium tin oxide films, conductive TFMs exhibited good electrical conductivities (9 Ω per square (Ω·sq−1), 78% transmittance at 550 nm) and notable mechanical performance (to bear abundant bending stresses).

In recent years, due to the special structure and performance, more and more techniques and methods were developed for preparing core-spun yarn. In this article, the submicron-cotton/polyester composite core-spun yarn is produced on conventional ring spinning, in which the polyester staple fibers as core and the sheath were submicron-cotton (Sm-C) fibers, the Sm-C sliver produced by carding machine equipped with a dish-shaped electrospinning device and the core-spun polyester roving covered Sm-C sliver was produced by the roving frame with the modified bell mouth. Three different ratios of submicron-cotton/polyester roving were spun based on the prepared Sm-C sliver, which shows roving formed a core-sheath structure. The coverage rate reaches 100%. The 85Sm-C/15T performance shows that the weight CV (1.0%) and evenness CV (5.0%), then use it to prepare three kinds of spun yarns with 800TPM, 900TPM, and1000TPM, when the twist was increased the structure of the yarn becomes more compact, the long-staple cotton fibers and submicron fibers were intermingled and entangled with each other, and the strength of 900TPM increases by 18.79% compared with 800TPM, the evenness CV decreases by 2.22%, compared with 900TPM, the 1000TPM elongation breaking decreased 9.33%. Consequently, the modified spinning methodology improved the coverage rate, structure, and mechanical properties of submicron-cotton/polyester composite core-spun yarn.

Abstract One-dimensional (1D) SiO2 nanofibers (SNFs), one of the most popular inorganic nanomaterials, have aroused widespread attention because of their excellent chemical stability, as well as unique optical and thermal characteristics. Electrospinning is a straightforward and versatile method to prepare 1D SNFs with programmable structures, manageable dimensions, and modifiable properties, which hold great potential in many cutting-edge applications including aerospace, nanodevice, and energy. In this review, substantial advances in the structural design, controllable synthesis, and multifunctional applications of electrospun SNFs are highlighted. We begin with a brief introduction to the fundamental principles, available raw materials, and typical apparatus of electrospun SNFs. We then discuss the strategies for preparing SNFs with diverse structures in detail, especially stressing the newly emerging three-dimensional SiO2 nanofibrous aerogels. We continue with focus on major breakthroughs about brittleness-to-flexibility transition of SNFs and the means to achieve their mechanical reinforcement. In addition, we showcase recent applications enabled by electrospun SNFs, with particular emphasis on physical protection, health care and water treatment. In the end, we summarize this review and provide some perspectives on the future development direction of electrospun SNFs.

Abstract Stretchable thermoelectrics have recently attracted widespread attention in the field of self‐powered wearable electronics due to their unique capability of harvesting body heat. However, it remains challenging to develop thermoelectric materials with excellent stretchability, durable thermoelectric properties, wearable comfort, and multifunctional sensing properties simultaneously. Herein, an advanced preparation strategy combining electrospinning and spraying technology is proposed to prepare carbon nanotube (CNT)/polyvinyl pyrrolidone (PVP)/polyurethane (PU) composite thermoelectric fabrics that have high air permeability and stretchability (~250%) close to those of pure PU nanofiber fabrics. Furthermore, PVP can not only improve the dispersion of CNTs but also act as interfacial binders between the CNT and the elastic PU skeleton. Consequently, both the electrical conductivity and the Seebeck coefficient remain unchanged even after bending 1000 times. In addition, self‐powered sensors for the mutual conversion of finger temperature and language and detection of the movement of joints to optimize an athlete's movement state were successfully fabricated. This study paves the way for stretchable thermoelectric fabrics with fascinating applications in smart wearable fields such as power generation, health monitoring, and human–computer interaction.

Ceramic aerogels are generally brittle and often tend to structurally collapse under large external tensile strain. Here the authors synthesize large-scale stretchable ceramic aerogels with interwoven crimped nanofibers by combining electrohydrodynamic method and 3D reaction electrospinning.

Smart generators that collect energy from the ambient environment are a new approach for meeting growing global energy needs. Moisture is one of the most abundant resources in the ambient environment, and using it to generate electricity has aroused great interest in recent years. In this review, we first summarize the emerging design principles of moisture power generation, including ion diffusion, streaming potential, and charged surface potential. Then, based on these fundamental principles, we systematically summarize the materials thus far known to be suitable for moisture power generation. Finally, we highlight the application of moisture energy generators in various fields, such as thermoelectricity, solar thermal evaporation, capacitors, strain sensors, and information storage, and discuss current challenges and future prospects for the development of moisture energy generators.

Noise pollution has been a burden to the global economy, environment, and human health. Here the authors demonstrate a facile route to produce flexible ceramic nanofibrous sponges with hierarchically entangled graphene networks and its excellent noise absorption properties at elevated temperatures.

In spite of the great progress of wound healing materials, the development of dressing with moisture permeability, stretchable capability, and adhesive performance remains a huge challenge. In this study, gelatin-dopamine (GT-DA) nanofiber membrane was prepared by introducing dopamine (DA) into gelatin (GT) via electrospinning followed by in-situ reaction. The effects of DA dosage, crosslinking condition and crosslinking time on the mechanical properties of the fiber membrane were studied systematically. The resultant GT-DA nanofibrous hydrogels exhibited integrated stress strength of 1.96 MPa, good water absorption of 700%, and water vapor transmission (WVT: 4.3 kg m−2d−1), which were superior than those of Mepiform®, a commercial adhesive silicone dressing. In addition, Fe3+ were introduced into one side of the nanofiber membrane. A stronger adhesion strength of 2.5 KPa on the porcine skin, which was 1.6 times higher than that of Mepiform® was achieved. Our research showed that the prepared nanofibrous hydrogel has potential as wound dressing and could be used in post-traumatic tissue healing engineering. This work presented a type of breathable, stretchable and adhesive nanofibrous hydrogels, which would ensure the stable attachment on wounds during movement as a wound healing material.

Cooperation evolution emerges in diversities of social networks by way of individuals’ interactions and influence propagations. The influence on cooperation evolution owing to the multiplex nature of social networks and interactions is still an open question. In this work, we focus on the impacts of the individuals’ heterogeneous properties and the networks’ multilayer nature on cooperation evolution, and propose a heterogeneous diffusion model to describe and analyze the cooperation dynamics processes in diverse layers of multiplex networks with weighted values. We investigated how the interlayer and intralayer interactions with these heterogeneities influence individuals’ behaviors and strategies, and discussed how some important parameters impact the cooperation densities and evolution processes in the interactions of different strategy games. The experimental results show that the tighter interlayer interaction can obviously improve the cooperation densities in the strategy games SG, but has little impact on the cooperation evolution in the strategy games PD. The effect of individuals’ trust on cooperation diffusion is smaller in the games PD than in the games SG. The heterogeneity of degree distribution between individuals from interlayer networks also affects cooperation processes. This work explores and reveals the mechanism and regular pattern of cooperation diffusion considering the heterogeneities of individuals in multiplex networks with weighted values.

Creating two-dimensional carbon nanoscale building blocks is of fundamental importance, but is extremely challenging. Here, the authors report a facile electro-spraying/netting technique for self-assembly of two-dimensional carbon nanostructured networks with superflexibility and multi-functionality.

Desiccants are important for dehumidification, but application is hindered by limited hygroscopicity, recyclability, and energy efficiency. Here, the authors report a moisture pump comprised of an electrospun nanofibrous memebrane for solar-driven continuous indoor dehumidification.

Conductive porous carbons are promising for a variety of applications, but simultaneously tuning porosity and conductivity is challenging. Here, the authors develop a green method to fabricate flexible boron-nitrogen-fluorine triply doped carbon nanofibers with high porosity and conductivity.

Freestanding carbon nanofiber (CNF) films are promising flexible battery electrodes because of their rich functionalities and the avoidance of the unnecessary usage of conductive additives and binders, which introduce additional interfacial resistance. However, most reported freestanding CNF electrodes have lower energy density than the metrics of practical usage. Herein, an in situ welding strategy is proposed to fabricate flexible CNF electrodes with both high packing density (0.343 g cm−3) and capacity (832.4 mA h g−1 @0.1 C) by electrospinning of a polyacrylonitrile (PAN) and poly(vinyl‐butyral) (PVB) sol followed by pyrolysis. The addition of 20 wt% of low‐thermal‐stability PVB into PAN carbon precursors endows the CNFs with mixed amorphous/graphitic carbon domains and welded structures. The former enhances the capacity and long‐cycling stability, and the latter improves the flexibility and packing density of the anodes. As a result, these flexible anodes display stable reversible capacities of 430 mA h g−1 @1 C over 1000 cycles and excellent rate performance from 0.1 to 5 C. The successful fabrication of high‐capacity CNF anodes at commercial‐level density opens a new avenue for their practical application.

Summary: Silica is an attractive anode material for soft lithium batteries owing to its high specific capacity, but it suffers severe problems of large volume change and unstable solid-electrolyte interface. Moreover, it is a challenge to fabricate flexible silica anodes. Here, we report a low-cost and scalable strategy to create flexible anodes of N-doped carbon nanofiber-confined porous silica (p-SiO2@N-CNF) by developing a sol-gel electrospinning process followed by carbonization. This approach causes the p-SiO2 nanoparticles (NPs) to be self-assembled within the N-CNFs, which act like elastomer and electrolyte barrier to accommodate volume changes and to enhance the stability of SiO2, whereas the NPs act as soft plasticizer providing strength to the CNF skeletons. Benefiting from the hierarchical structures, the anodes with high p-SiO2 loadings (>1.6 mg/cm2) exhibit exceptional cycling performance (>1,000 cycles) in terms of bending, current rate, and capacity. Moreover, the batteries remain stable when discharging at 0.5 C and charging at 2 C. : Electrochemical Energy Storage; Nanomaterials; Materials Characterization; Porous Material Subject Areas: Electrochemical Energy Storage, Nanomaterials, Materials Characterization, Porous Material

Summary: Oxide ceramic materials underpin a wide variety of technologies. However, the inherent fragility of these materials limits their use in emerging fields like wearable electronics and soft energy storage devices. Here, we develop a sol-gel electrospinning technique followed by calcination to create a range of oxide ceramic nanofiber films that exhibit significant softness without fragility after various deformations. This approach causes the ceramic crystals to fuse together at a low temperature during their growth within the polymer nanofiber templates. All the synthesized ceramic films, from SiO2 to BaTiO3, Li0.33La0.56TiO3, and Li7La3Zr2O12, have silk-like softness of 900% and high thermal insulation performance, enhancing the rate capability and safety of lithium batteries. The reported method allows scalable synthesis of soft oxide ceramic films with properties appealing for applications. : Ceramics; Chemistry; Inorganic Chemistry; Inorganic Materials; Materials Science; Polymers Subject Areas: Ceramics, Chemistry, Inorganic Chemistry, Inorganic Materials, Materials Science, Polymers

Nanofibrous networks are applied in environmental protection and electrical or bioengineering and experience a great demand, but the design of these functional materials is challenging. Here the authors demonstrate an electronetting technology for fabricating self-assembled nanonets from various materials.

Reasonable structural design of the spinneret plays vital roles in high-quality electrospinning technology. Free-surface electrospinning is among the most efficient needleless electrospinning techniques. However, current free-surface spinnerets have large exposed solution surface, ambiguous electric field, and poor ability stabilizing liquid. Herein, a novel mushroom shaped electrospinning (mushroom-electrospinning) that has a smooth cover was developed to overcome existing problems. The new setup promoted the formation of stable annular pre-Taylor cones with high curvature. The finite element analysis indicated that the mushroom-spinneret avoided the appearance of competitive electric field and concentrated the surface charge of the solution on the pre-Taylor cones. Consequently, the spinneret exhibited an outstanding production capacity of 13.7 g/h and all electrospun membranes showed superior narrow diameter distributions (CV ~ 10%). These novel understandings provide a promising avenue for generating nanofibers with enhanced yield and quality.

The effects of particle morphology on the structure and swelling/dissolution and rheological properties of nascent ultra-high molecular weight polyethylene (UHMWPE) in liquid paraffin (LP) were elaborately explored in this article. Nascent UHMWPE with different particle morphologies was prepared via pre-polymerization technique and direct polymerization. The melting temperature and crystallinity of UHMWPE resins with different particle morphologies were compared, and a schematic diagram was proposed to illustrate the mechanism of UHMWPE particle growth synthesized by pre-polymerization method and direct polymerization. The polymer globules in the nascent UHMWPE prepared by using pre-polymerization technique are densely packed and a positive correlation between the particle size and the viscosity-averaged molecular weight can be observed. The split phenomenon of particles and the fluctuation in the viscosity of UHMWPE/LP system prepared by direct polymerization can be observed at a low heating rate and there is no correlation between particle size and viscosity-averaged molecular weight.

Effective moisture transfer is a fundamental process in natural systems, especially plants, and serves as an inspiration for engineered materials. Despite outstanding progress in bionic engineering to simulate water movement within trees, biomimetic design in one-dimensional (1D) fiber assemblies is still limited. Here, an advanced composite yarn structure inspired by the moisture transfer in trees is reported. Utilizing the scale difference between cotton fibers and electrospun nanofibers, the engineered tree-like-core spun yarn effectively transported liquid moisture from one side of the yarn to the other. The core structure of the spun yarn was precisely designed by controlling the fineness of the nanofibers and the thickness of the nanofiber layer. Moreover, fabrics based on the tree-like-core spun yarn had reduced relative water content on the top surface (0%) and a high one-way transport index of 846%, which is more than twice as high as traditional fabrics, demonstrating potential for moisture-heat transmission, biosensors, and microfluidics applications. Keywords: Tree-like structure, Microfluidics flow, Electrospun nanofiber yarns, Yarn structure, Moisture wicking

In contrast to yarns of micro-fibers and those of nano-fibers, composite yarns composed of micro- and nano-fibers exhibit great potential in functional applications by integrating the respective advantages of multiscale fibers. However, the efficient fabrication of composite yarns remains challenging. So far, the existing nano-fiber included yarns, such as nanofiber yarn and core-sheath yarn, exhibit poor durability and low preparation efficiency. Herein, an efficient hybrid strategy for the composite yarns made of multiscale fibers has been developed by integration of electrospun nano-fibers and webbing of micro-fibers. Polyacrylonitrile nano-fiber/viscose micro-fiber composite yarns have been prepared massively. To explore structure of the resulting composite yarns, fluorescent tracer technique was adopted and revealed that nano-fibers are dispersed within composite yarn uniformly, while the structure of composite yarns can be governed easily by adjusting electrospinning parameters. Compared to pure yarns of viscose micro-fibers, the composite yarns possess mechanical properties at the same level, enabling the weaving, knitting and braiding of it for industrial applications. Furthermore, the formation mechanism of the composite yarn has been investigated and the fibrous adhesion among multiscale fibers has been modeled. The efficient approach should be a promising one for the design and scalable fabrication of composite yarns of micro-/nano-fibers. Keywords: Composite yarn, Nanofiber, Electrospinning, Fluorescent tracer technique, Fibrous adhesion, Nanofiber breakage

Conductive composites: Polymer nanofibre composite rivals metal New method has enabled preparation of polymer-metal composite nonwovens with very low metal loading but metal-like high conductivity. A collaborative team led by Andreas Greiner from University of Bayreuth, Germany demonstrates that by reducing the percolation threshold significantly with a wet-laid method, silver nanowire and polymer composite nonwovens show high electrical conductivity of 750.000S/m at only 3.4 vol% loading of silver. It can be attributed to the homogenous distribution of the silver nanowires in the electrospun polymer fibres. In addition, the high conductivity of the composites is almost fully resistive to bending. These nice features enable the use of the conductive composite nonwovens in various flexible, lightweight and economic applications, such as portable Joule heaters with very low operating voltages of only 1.1 V.

Abstract Self-standing photocatalytic membranes constructed from TiO2 nanofibers hold great promise in environmental remediation; however, challenges still remained for the poor mechanical properties of polycrystalline TiO2 nanofibers. Herein, soft Zr-doped TiO2 (TZ) nanofibrous membranes with robust mechanical properties and enhanced photocatalytic activity were fabricated via electrospinning technique. The Zr4+ incorporation could effectively inhibit the grain growth and reduce the surface defects and breaking point of TiO2 nanofiber. The as-prepared TZ membranes were composed of well-interconnected nanofibers with a high aspect ratios, small grain size and pore size, which exhibited good tensile strength (1.32 MPa) and showed no obvious damage after 200 cycles of bending to a radius of 2 mm. A plausible bending deformation mechanism of the soft TZ membranes was proposed from microscopic single nanofiber to macroscopical membranes. Moreover, the resultant TZ membranes displayed better photocatalytic performance for methylene blue degradation compared to a commercial catalyst (P25), including high degradation degree of 95.4% within 30 min, good reusability in 5 cycles, and easiness of recycling. The successful preparation of such fascinating materials may open up new avenues for the design and development of soft TiO2-based membranes for various application.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Akund fiber is a new type of natural cellulose fiber. Because of its excellent properties, akund fiber has become one of the new ecological materials which have huge development potential. Recently natural fibers have shown great promise in a variety of applications that were previously dominated by synthetic fibers due to their important aspects of biocompatibility, possible biodegradation, nontoxicity, and abundance. Moisture absorption and release behaviour of natural fiber plastic composites is one major concern in their outdoor applications. So the knowledge of the moisture content and the moisture absorption and release rate is very much essential for the application of akund fiber as an excellent reinforcement in polymers. An effort has been made to study the moisture absorption and release behaviour of akund fiber and the mechanical performance of it at relative air humidity from 0% to 100%. The gain and loss in moisture content in akund fiber due to water absorption and release were measured as a function of exposure time under the environment, in which temperature is 20°C and humidity is 65%. The regression equations of the absorption and release process were established.

Mammarian enabled (Mena), a member of the Enabled (Ena)/Vasodilator-stimulated phosphoprotein (VASP) family of proteins, has been implicated in cell motility through regulation of the actin cytoskeleton assembly, including lamellipodial protrusion. Rac1, a member of the Rho family GTPases, also plays a pivotal role in the formation of lamellipodia. Here we report that human Mena (hMena) colocalizes with Rac1 in lamellipodia, and using an unmixing assisted acceptor depletion fluorescence resonance energy transfer (u-adFRET) analysis that hMena associates with Rac1 in vivo in the glioblastoma cell line U251MG. Depletion of hMena by siRNA causes cells to be highly spread with the formation of lamellipodia. This cellular phenotype is canceled by introduction of a dominant negative form of Rac1. A Rac activity assay and FRET analysis showed that hMena knock-down cells increased the activation of Rac1 at the lamellipodia. These results suggest that hMena possesses properties which help to regulate the formation of lamellipodia through the modulation of the activity of Rac1.

Oxide ceramics serve as crucial functional structural materials with vast applications across multiple domains of human production and everyday life. However, their inherent brittleness and heightened susceptibility to defects render them prone to failure under external stresses. Here, a grain-boundary toughening strategy is employed to construct Gd2O3 nanofibers (GNFs), which exhibit remarkable mechanical properties such as stretchability, bendability and even knotability. By leveraging the disparity between grain boundary diffusion and grain boundary migration dynamics, we delicately reduce the grain size and increase grain boundary barriers within GNFs. The tightly interlocked fine grains and soft grain boundaries significantly enhance the flexibility of GNFs. The resultant GNFs exhibit remarkable homogeneity, solidity, and pliability, while showcasing an exceptional elastic strain capacity of up to 2.3%. They can endure hundreds of bending cycles without displaying noticeable deformation. This investigation elucidates a fresh and effective strategy for developing robust and flexible oxide ceramic materials. [ABSTRACT FROM AUTHOR]