Preparation of Regenerated Silk Fibroin Hybrid Fibers with Hydrogen Peroxide Sensing Properties by Wet Spinning

Silk is widely used in the production of high-quality textiles.At the same time,the amount of silk textiles no longer in use and discarded is increasing,resulting in significant waste and pollution.This issue is of great concern in many countries where silk is used.Hydrogen peroxide as a naturally occurring compound is an important indicator of detection in both biology and the environment.This study aims to develop a composite fiber with hydrogen peroxide-sensing properties using discarded silk materials.To achieve this goal,firstly,polydopamine(PDA)was used to encapsulate the ZnFe_(2)O_(4) NPs to achieve the improvement of dispersion,and then regenerated silk fibroin(RSF)and PDA@ZnFe_(2)O_(4)/RSF hybrid fibers are prepared by wet spinning.Research has shown that PDA@ZnFe_(2)O_(4)/RSF demonstrates exceptional sensitivity,selectivity,and stability in detecting hydrogen peroxide,while maintaining high mechanical strength.Furthermore,the complete hybridization of PDA@ZnFe_(2)O_(4) with silk fibroin not only results in the combination of the durability of silk fibroin and PDA@ZnFe_(2)O_(4)’s rigidity,ensuring a reliable service life,but also makes PDA@ZnFe_(2)O_(4)/RSF exhibit excellent catalytic activity and biocompatibility.Therefore,the composite fiber exhibits exceptional mechanical properties and reliable hydrogen peroxide sensing capabilities,making it a promising material for biological and medical applications.

Wet spinning of fiber-shaped flexible Zn-ion batteries toward wearable energy storage

High-performance flexible one-dimensional(1D)electrochemical energy storage devices are crucial for the applications of wearable electronics.Although much progress on various 1D energy storage devices has been made,challenges involving fabrication cost,scalability,and efficiency remain.Herein,a highperformance flexible all-fiber zinc-ion battery(ZIB)is fabricated using a low-cost,scalable,and efficient continuous wet-spinning method.Viscous composite inks containing cellulose nanofibers/carbon nanotubes(CNFs/CNTs)binary composite network and either manganese dioxide nanowires(MnO_(2) NWs)or commercial Zn powders are utilized to spinning fiber cathodes and anodes,respectively.MnO_(2) NWs and Zn powders are uniformly dispersed in the interpenetrated CNFs/CNTs fibrous network,leading to homogenous composite inks with an ideal shear-thinning property.The obtained fiber electrodes demonstrate favorable uniformity and flexibility.Benefiting from the well-designed electrodes,the assembled flexible fiber-shaped ZIB delivers a high specific capacity of 281.5 m Ah g^(-1) at 0.25 A g^(-1) and displays excellent cycling stability over 400 cycles.Moreover,the wet-spun fiber-shaped ZIBs achieve ultrahigh gravimetric and volumetric energy densities of 47.3 Wh kg^(-1) and 131.3 m Wh cm^(-3),respectively,based on both cathode and anode and maintain favorable stability even after 4000 bending cycles.This work offers a new concept design of 1D flexible ZIBs that can be potentially incorporated into commercial textiles for wearable and portable electronics.

Fabrication of High Toughness Silk Fibroin/Tungsten Disulfide Nanoparticles Hybrid Fiber and Self-Heating Textile by Wet Spinning|

Traditionally,silkworm silk has been used to make high-quality textiles.Nevertheless,various wastes from silk-worm silk textiles that are no longer used are increasing.which is also causing considerable waste and contam-ination.This issue is causing widespread concern in countries that use more silk.Regenerated silk fibroin(RSF)fibers have been shown to be fragile and tender,which prohibits RSF from being widely used as a structural com-ponent.Therefore,enriching the function of silk and enhancing the RSF mechanial properties are important directions to expand the comprehensive utilization of silk products.In the present research,wet spinning was used to create a series of RSF/tungsten disulfide(WS_(2))nanoparticles(NPs)hybrid fiber having distinct WS_(2) nanoparticles concentrations.It was discovered that the temperature of hybrid fibers containing 0.8 wt%RSF/WS_(2) nanoparticles might climb from 20.4℃ to 85.6℃in 1 min and 108.3℃ in 10 min after being exposed to simulated sunlight for a period of one minute and ten minutes.It also had certain antibacterial activity and thermal stability.Fabrics created by hand mixing had outst anding photothermal characteristics under natural sunlight.Further-more,adding WS_(2) nanoparticles might increase the tensile properties of hybrid fibers,which could be caused by the reality that the blending of WS_(2) nanoparticles inhibited the self-assembly of sheets in RSF reaction mixture in a dosage dependent way,as evidenced by the fact that RSF/WSz nanoparticles hybrid fibers had lesser β-sheets material,crystalline nature,and arystalline size.The above performance makes the RSF/WS_(2) nanoparticles hybrid fbers promising candidates for application in photothermal fabrics as well as military dothing.

Carrageenan Fiber Prepared by a New Process Route of Ba^(2+)Ion Pre-Crosslinking in the Spinning Solution

Ba^(2+)pre-crosslinked carrageenan fiber(Ba/CAF)was prepared by adding a small amount of Ba^(2+) to the carrageenan(CA)solution as the spinning solution.Ba/CAF-n/A,Ba/CAF-n/B and Ba/CAF-n/C were prepared with ethanol solution(combine A),high concentration BaCl_(2)solution(combine B)and low concentration BaCl_(2)solution(combine C),as coagulation bath and stretch bath,respectively.The combination of coagulation bath and stretch bath suitable for Ba^(2+) pre-crosslinking wet spinning was screened.The results showed that Ba^(2+) can induce the birefringence of the CA molecular chain,and the Ba^(2+) pre-crosslinking effect is the best when the CA mass fraction is 8.0 wt%.From the perspective of production safety,fiber performance and spinning cost,the coagulation bath of 3.5 wt%BaCl_(2)solution and stretch bath of 1.7 wt%BaCl_(2)solution,that is,combination C with low concentration BaCl_(2)solution,is the best choice.Ba/CAF-8.0/C was obtained under the best conditions.The linear intensity,water absorption and flame retardancy study showed that the breaking strength of Ba/CAF-8.0/C is as high as 1.61 cN/dtex,the water absorption was 649.2%and 574.3%,in deionized water and normal saline,respectively,and the LOI value reached 32.

Gamma(ɣ)‑MnO_(2)/rGO Fibered Cathode Fabrication from Wet Spinning and Dip Coating Techniques for Cable‑Shaped Zn‑Ion Batteries

Cable/fber-shaped Zn-ion batteries are designed to power wearable electronics that require high fexibility to operate on human body.However,one of technical challenges of these devices is the complexity and high cost for manufacturing fbered cathode.In this work,we demonstrated gamma manganese oxide(ɣ-MnO_(2))/reduced graphene oxide(rGO)fbered cathode fabrication using facile and cost-efective fber production and active material coating techniques.Specifcally,rGO fbers were fabricated via wet spinning,followed by chemical reduction with hydroiodic acid(HI).The synthesized rGO fber bundle was then dip-coated with a mixture ofɣ-MnO_(2),carbon black or multi-walled carbon nanotubes,and xanthan gum or polyvinylidene fuoride binder to obtainɣ-MnO_(2)/rGO fbered cathode.We studied the efect of binders and conductive materials on physical properties and electrochemical performance of the fbered cathode.It was found that hydrophobic binder had more benefts than hydrophilic binder by providing higher active material loading,better coating layer homogeneity,and more stable electrochemical performance.Cable-shaped Zn-ion batteries(CSZIBs)were then assembled by using theɣ-MnO_(2)/rGO fbered cathode,Zn wire anode,and xanthan gum polymeric gel electrolyte with 2 M ZnSO_(4) and 0.2 M MnSO_(4) salts without a separator.We investigated the battery assembling procedure on a glass slide(prototype ZIB)and in a plastic tube(cable-shaped ZIB),and evaluated their electrochemical performance.The CSZIB showed promising maximum capacity of~230 mAh/g with moderate cycling stability(80%capacity retention after 200 cycles)and high fexibility by maintaining the potential after consecutive pressing for 200 times under controlled pressing distance,duration,and testing speed.Finally,we explored ion intercalation behaviours and proposed a H^(+)/Zn^(2+)co-intercalation mechanism in ZIB withɣ-MnO_(2) active material.

Temperature‑Arousing Self‑Powered Fire Warning E‑Textile Based on p-n Segment Coaxial Aerogel Fibers for Active Fire Protection in Firefighting Clothing

Firefighting protective clothing is a crucial protective equipment for firefighters to minimize skin burn and ensure safety firefighting operation and rescue mission.A recent increasing concern is to develop self-powered fire warning materials that can be incorporated into the firefighting clothing to achieve active fire protection for firefighters before the protective clothing catches fire on fireground.However,it is still a challenge to facilely design and manufacture thermoelectric(TE)textile(TET)-based fire warning electronics with dynamic surface conformability and breathability.Here,we develop an alternate coaxial wet-spinning strategy to continuously produce alternating p/n-type TE aerogel fibers involving n-type Ti_(3)C_(2)T_(x)MXene and p-type MXene/SWCNT-COOH as core materials,and tough aramid nanofiber as protective shell,which simultaneously ensure the flexibility and high-efficiency TE power generation.With such alternating p/n-type TE fibers,TET-based self-powered fire warning sensors with high mechanical stability and wearability are successfully fabricated through stitching the alternating p-n segment TE fibers into aramid fabric.The results indicate that TET-based fire warning electronics containing 50 p-n pairs produce the open-circuit voltage of 7.5 mV with a power density of 119.79 nW cm-2 at a temperature difference of 300℃.The output voltage signal is then calculated as corresponding surface temperature of firefighting clothing based on a linear relationship between TE voltage and temperature.The fire alarm response time and flame-retardant properties are further displayed.Such self-powered fire warning electronics are true textiles that offer breathability and compatibility with body movement,demonstrating their potential application in firefighting clothing.

Scalable one-step wet-spinning of triboelectric fibers for large-area power and sensing textiles

Textile-based electronic devices have attracted increasing interest in recent years due to their wearability,breathability,comfort.Among them,textile-based triboelectric nanogenerators(T-TENGs)exhibit remarkable advantages in mechanical energy harvesting and self-powered sensing.However,there are still some key challenges to the development and application of triboelectric fibers(the basic unit of T-TENG).Scalable production and large-scale integration are still significant factors hindering its application.At the same time,there are some difficulties to overcome in the manufacturing process,such as achieving good stretchability and a quick production,overcoming incompatibility between conductive and triboelectric materials.In this study,triboelectric fibers are produced continuously by one-step coaxial wet spinning.They are only 0.18 mm in diameter and consist of liquid metal(LM)core and polyurethane(PU)sheath.Due to the good mechanical properties between them,there is no interface incompatibility of the triboelectric fibers.In addition,triboelectric fibers can be made into large areas of T-TENG by means of digital embroidery and plain weave.The T-TENGs can be used for energy harvesting and self-powered sensing.When they are fixed on the forearm can monitor various strokes in badminton.This work provides a promising strategy for the large-scale fabrication and large-area integration of triboelectric fibers,promotes the development of wearable T-TENGs.

THERMAL DEGRADATION AND FLAME RETARDANCY OF CALCIUM ALGINATE FIBERS

Calcium alginate fibers were prepared by wet spinning of sodium alginate into a coagulating bath containing calcium chloride.The thermal degradation and flame retardancy of calcium alginate fibers were investigated with thermal gravimetry(TG),X-ray diffraction(XRD),limiting oxygen index(LOI) and cone calorimeter(CONE).The results show that calcium alginate fibers are inherently flame retardant with a LOI value of 34,and the heat release rate(HRR),total heat release(THR),CO and CO_2 concentrations during com...

Polyacrylonitrile/Graphene-Based Coaxial Fiber-Shaped Supercapacitors

Supercapacitors have huge potential applications in the field of wearable electronic devices,such as flexible displays,flexible biosensors and implantable multimedia devices,due to their high-power density,fast charge-discharge rates,long cycling life,and relatively simple configuration.In this paper,we demonstrated hierarchically porous and continuous reduced graphene oxide-polyacrylonitrile@polyacrylonitrile(rGO-PAN@PAN)coaxial fibers with certain strength,excellent electrochemical performance through coaxial wet spinning and thermal reduction.Coaxial fibers are carbonized at high temperature and have a graded porous structure with a conductivity of 1703 S/m.The areal specific capacitance of the supercapacitor assembled by polyvinyl alcohol/sulfuric acid(PVA/H_(2)SO_(4))gel electrolyte is 11.56 mF/cm^(2),and its energy density reaches 0.21 mW·h/cm3,showing good electrochemical performance.Graphene-based coaxial fibers prepared by wet spinning have a great prospect of application in electronic devices due to their excellent properties.

MXene fibers for electronic textiles:Progress and perspectives

The rapid evolution of portable and wearable electronic devices has fueled the development of smart functional textiles that are able to conduct electricity,sense body movements,or store energy.One main challenge inhibiting the further development of functional textile-based electronics is the lack of robust functional fibers with suitable electrical,electrochemical and sensing functionalities.MXenes,an emerging family of two-dimensional(2D)materials,have shown to be promising candidates for producing functional fibers due to their exceptional electrical and electrochemical properties combined with solution processability.The unique ability of MXenes to readily form liquid crystal phases in various solvents has allowed them to generate additive-free fibers using a wet spinning process.In this work,we review the recent exciting developments in the fabrication of neat MXenes fibers and present a critical evaluation of practical challenges in MXenes processing that influence the macroscale material properties and the performance of the subsequent devices.We also provide our assessment for the future opportunities and challenges in producing MXene fibers to help pave the way for their widespread use in advanced wearable applications.

Synthesis of silicone blocked bio-polyurethane and its application in highly stretchable fiber-shaped strain sensor

Flexible strain sensors have become a key component of intelligent wearable electronics.However,the fabrication of strain sensors with wide workable strain ranges and high sensitivity remains a great challenge.Additionally,the rapid development of polymer composites based strain sensors has produced a large amount of e-waste.Therefore,the development of strain sensors with wide strain sensing ranges and high sensitivity based on degradable materials is necessary.In this work,a silicone blocked polyurethane(Si-BPU)with high stretchability and degradability was synthesized and composited with carbon nanotubes(CNTs)to fabricate fibrous strain sensors.The synthesized 0.5%Si-BPU exhibited good biodegradability with a weight loss of 16.47%in 42 days.The Si-BPU/12CNTs fiber based strain sensor achieved a sensing range of 0%–353.3%strain,gauge factor(GF)of 206.3 at 250%strain and of 4,513.2 at 353.3%strain,reliable stability under 10,000 repeated stretching–releasing cycles.Moreover,the Si-BPU/12CNTs strain sensor showed rapid response time(<163 ms)and was capable of monitoring various human body movements(elbow bending,finger bending,breath,swallow).In consequence,this work provides a new and effective strategy for the development of sustainable wearable electronic devices.

Flexible thermochromic fabrics enabling dynamic colored display

Color-changeable fbers can provide diverse functions for intelligent wearable devices such as novel information displays and human-machine interfaces when woven into fabric.This work develops a low-cost,efective,and scalable strategy to produce thermochromic fbers by wet spinning.Through a combination of diferent thermochromic microcapsules,fexible fbers with abundant and reversible color changes are obtained.These color changes can be clearly observed by the naked eye.It is also found that the fbers exhibit excellent color-changing stability even after 8000 thermal cycles.Moreover,the thermochromic fbers can be fabricated on a large scale and easily woven or implanted into various fabrics with good mechanical performance.Driven by their good mechanical and physical characteristics,applications of thermochromic fbers in dynamic colored display are demonstrated.Dynamic quick response(QR)code display and recognition are successfully realized with thermochromic fabrics.This work well confrms the potential applications of thermochromic fbers in smart textiles,wearable devices,fexible displays,and human-machine interfaces.

Synthesis and Properties of Novel Polyimide Fibers Containing Phosphorus Groups in the Side Chain (DATPPO)

A series of polyamic acid copolymers(co-PAAs) containing phosphorous groups in the side chains were synthesized from [2,5-bis(4-aminophenoxy) phenyl] diphenylphosphine oxide(DATPPO) and 4,4′-oxydianiline(ODA) with 3,3′,4,4′-biphenyltetracarboxylic dianhydride(s-BPDA) through the polycondensation in N,N′-dimethyacetamide(DMAc). The co-PAA solutions were spun into fibers by a dry-jet wet spinning process followed by thermal imidization to obtain co-polyimide(co-PI) fibers. FTIR spectra and elemental analysis confirmed the chemical structure of PI fibers. SEM results indicated that the resulting PI fibers had a smooth and dense surface, a uniform and circle-shape diameter. The thermogravimetric measurements showed that with the increase of DATPPO content, the resulting PI fibers possessed high decomposition temperature and residual char yield, indicating that the PI fibers had good thermal stability. The corresponding limiting oxygen index(LOI) values from the experiment results showed that the co-PI fibers possessed good flame-retardant property. Furthermore, the mechanical properties of the co-PI fibers were investigated systematically. When the DATPPO content increased, the tensile strength and initial modulus of the co-PI fibers decreased. However, the mechanical properties were improved by increasing the draw ratio of the fibers. When the draw ratio was up to 2.5, the tensile strength and initial modulus of the co-PI fibers reached up to 0.64 and 10.02 GPa, respectively. The WAXD results showed that the order degree of amorphous matter increased with increased stretching. In addition, the SAXS results displayed that valuably drawing the fibers could eliminate the voids inside and lead to better mechanical property. WAXD revealed that the orientation of the amorphous polymer influenced the mechanical properties of the fibers.