Wearable and washable textile-based strain sensors via a single-step, environment-friendly method

Recently, soft and stretchable strain sensors that can be incorporated into textiles have attracted significantly increasing interest for use in a diverse range of applications. However, the simple fabrication of stretchable devices that exhibit excellent sensing performance, are highly durability and are a good fit to the human body remains a challenge. Herein, we describe the fabrication of a new flexible strain sensor on a traditional polyester fabric using a one-step method that involves the reduction of graphene oxide(GO) using ascorbic acid(L-AA). The resulting textile-based strain sensors could be washed, exhibited long-term stability,and had a negative linear response that gave a good sensing response when used in wearable applications. In addition to effectively detecting human motions, the textile was modified such that it could detect ultra-large deformations. The impressive mechanical performance, durability and the ability to capture and monitor a variety of human actions and motions mean that these textile-based sensors have great potential in biomonitoring, soft co-robotics, and human-machine interactions.

Rheological properties and screen printability of UV curable conductive ink for flexible and washable E-textiles

As a critical component for the realization of flexible electronics,multifunctional electronic textiles(etextiles)still struggle to achieve controllable printing accuracy,excellent flexibility,decent washability and simple manufacturing.The printing process of conductive ink plays an important role in manufacturing e-textiles and meanwhile is also the main source of printing defects.In this work,we report the preparation of fully flexible and washable textile-based conductive circuits with screen-printing method based on novel-developed UV-curing conductive ink that contains low temperature and fast cure features.This work systematically investigated the correlation between ink formulation,rheological properties,screen printability on fabric substrates,and the electrical properties of the e-textile made thereafter.The rheological behaviors,including the thixotropic behavior and oscillatory stress sweep of the conductive inks was found depending heavily on the polymer to diluent ratio in the formulation.Subsequently,the rheological response of the inks during screen printing showed determining influence to their printability on textile,that the proper control of ink base viscosity,recovery time and storage/loss modulus is key to ensure the uniformity of printed conductive lines and therefore the electrical conductivity of fabricated e-textiles.A formulation with 24 wt%polymer and 10.8 wt%diluent meets all these stringent requirements.The conductive lines with 1.0 mm width showed exceptionally low resistivity of 2.06×10^(-5)Ωcm Moreover,the conductive lines presented excellent bending tolerance,and there was no significant change in the sample electrical resistance during 10 cycles of washing and drying processes.It is believed that these novel findings and the promising results of the prepared product will provide the basic guideline to the ink formulation design and applications for screen-printing electronics textiles.

Facile fabrication of highly conductive, waterproof, and washable e-textiles for wearable applications

曰ectronic textiles(e-textiles),known as a newly-developed innovation combining the textile and electronic technologies,are burgeoning as the next-generation of wearable electronics for lots of promising applications.However,a big concern is the durability of the e-textiles during practical using.Here,we describe a facile method tofabricate mechanically and electrically durable e-textiles by chemical deposition of silver nanoparticles(AgNPs)on widely used cotton fabric.The interface between AgNPs and fabric was tightly strengthened by the bioinspired polydopamine,and a highly waterproof and anticorrosive surface was further obtained by modifying with a fluorine containing agent of 1H,1H,2H,2/~/-perfuorodecanethiol(PFDT).In addition to the low sheet resistance of 0.26 ohm/sq and high conductivity of 233.4 S/cm,the e-textiles present outstanding stability to different mechanical deformations including ultrasonication,bending and machine washing.Moreover,thanks to the surface roughness of AgNPs and low surface energy of PFDT,a superhydrophobic surface,with a water contact angle of ca.152°,was further obtained,endowing the e-textiles excellent anti-corrosion to water,acid/alkaline solution and various liquids(e.g.,milk,coffee and tea).Finally,the application of this highly conductive e-textiles in wearable thermal therapy is demonstrated.Together with the facile,all-solution-based,and environmentally friendly fabrication protocol,the e-textiles show great potential of large-scale applications in wearable electronics.

Printable elastic silver nanowire-based conductor for washable electronic textiles

Printable elastic conductors promote the wide application of consumable electronic textiles (e-textiles) for pervasive healthcare monitoring and wearable computation. To assure a clean appearance, the e-textiles require a washing process to clean up the dirt after daily use. Thus, it is crucial to develop low-cost printable elastic conductors with strong adhesion to the textiles. Here, we report a composite elastic conductor based on Ag nanowires (NWs) and polyurethane elastomer. The composite could be dispersed into ink and easily printed onto textiles. One-step print could form robust conductive coatings without sealing on the textiles. Interestingly, the regional concentration of Ag NWs within the polyurethane matrix was observed during phase inversion, endowing the elastic conductor with a low percolation threshold of 0.12 vol.% and high conductivity of 3,668 S·cm^−1. Thanks to the high adhesion of the elastic conductors, the resulted e-textiles could withstand repeated stretching, folding, and machine washing (20 times) without obvious performance decay, which reveals its potential application in consumable e-textiles.

Biomass-derived washable composites for accelerating the healing of infected wounds

Advanced sustainable biomedical materials are urgently needed for clinical applications;however,developing biomedical materials with exceptional mechanical and bactericidal properties as well as removable functionalities to reduce unintended secondary injury remains a challenge.Here,we report a biomass-derived composite consisting of water-soluble fish gelatin(FG)and antibacterial ZnO@silk fibroin(ZSF)microspheres for potential application as the wound dressing.The ZSF microspheres are embedded in a FG matrix to realize the stretchable,antibacterial,and removable ZSF/FG composites.By introducing glycerin as the plasticizer,ZSF/FG composites deliver a tensile strength of 4.5 MPa and stretchability of 550%.Acting as both the germicide and hydrophile components,ZSF microspheres endow the composites with excellent antibacterial capacity and water solubility.To prevent secondary injury,the ZSF/FG composites can be easily removed from the wounds by simply exposing them to excess water.Additionally,the ZSF/FG composites exhibit favorable biocompatibility and sustain high cell viability of over 100%.The full-thickness skin wound model on infected mice demonstrated an efficient rate of wound closure and a reduced inflammatory response.The ZSF/FG composite shows promise to hasten the healing of infected wounds and is expected a promising candidate as wound dressing for clinical therapy.

PREPARATION AND APPLICATION OF A NEW ANTIFELTING RESIN FOR WOOL FABRICS

In this paper,a new resin called Resin M for imparting antifelting properties to wool fabricshas been studied.Resin M may be used by aqueous oxidative/polymer technique.It is provedthat Oxidant A/Resin M treatment can satisfy the machine washable requirement formulated byI.W.S..Resin M is a good agent for antifelting treatment of wool fabrics with proper pretreatment.Oxidant A/Resin M treatment has little influence on dyeing and moisture adsorption properties ofwool fibers.The pilling resistance of the treated fabrics is higher than that of the untreated ones.The strength and the handle of the treated fabrics have little been changed.According to thescanning electron microscope observations,it is recommended that the polymer encapsulation ofindividual fiber also plays an important role in the felting resistance of the treated fabrics though itis well known that the shrink resistance of the treated fabrics is believed to be due to the binding offibers.

Beneficiation of an Indian non-coking coal by column flotation

Beneficiation of non-coking coal is gaining ground in India. It not only reduces the volume of inert content to be transported to the power plant and also lowers the wear in the boiler houses. For special applications such as the fuel for integrated gasification combined cycle plant （IGCC）, the ash content in the coal should preferably be below 15 %. Indian coals are characterized by high inter-grown ash content mainly due to ＇drift origin＇ of Gondwana formation in Permian age. This warrants fine grinding of non-coking coal in order to liberate the ash forming minerals from coal macerals. A non- coking coal sample of vitrinite type from India was ground to 44 ~tm （dso） and subjected to column flotation to improve its quality. The non-coking coal analyzing 34.6 % ash, 26.2 % volatile matter, 1.3 % moisture and 37.9 % fixed carbon could be upgraded to a concentrate/froth of 14.83 % ash at 72.18 % yield by optimizing collector and frother dosages and flotation column operating parameters, namely, froth depth, superficial feed velocity and superficial air velocity. The concentrate produced by this process is suitable as fuel for IGCC in coal-to-electricity route.

Study on washability of microcrystal graphite using float-sink tests

This article presented an experimental research on washability of microcrystal graphite using float-sink tests.Chemical and X-ray analyses showed that graphite,semi-graphite,meta-anthracite,and anthracite existed together in this microcrystal graphite sample;and the intergrowth relationship between microcrystal graphite and gangues was very complicated based on optical mineralogy research.The results of float-sink tests revealed that:for the-25+0.5 mm size fraction,about 68%(by weight)of microcrystal graphite was obtained at the density of 2.0 g/cm^3.and the float product met the standard of commercial grade W65;for the-0.5 mm size fraction,58%(by weight)of microcrystal graphite was floated at the density of 2.0 g/cm^3,which met the standard of commercial grade W70.It can be concluded that microcrystal graphite may be upgraded by dense media separation(DMS)providing a float product using as the raw materials of casting or refractories.

Washability analysis of high sulfur coal gangue from a coal mine in Guizhou

Fulfill the screen test and float-and-sink analysis for high sulfur coal gangue from a Guizhou coal mine, analyzed the washability of its tail coal. Seen from the results： most of sulfur in sample is pyrite, the sulfur content of different particle classification shall be reduced with the decreasing of size and specific gravity, most of sulfur distributed in the coal particles with large-size and high specific gravity. Part of sulfur may be eliminated through special gravity separation, however, most of inorganic sulfur should be removed with the combination of floatation process.

Relationship Between Coal Facies and Washability of High-Sulfur Coal

The petrographic characteristics and facies of the high-sulfur coal (No. 9 coal seam) in Wuda coalfield were analyzed and the washability of stratified coal samples formed in the different coal facies was discussed using the density component method of coal petrology. The results show that the washability of different stratified coal samples in tbe same coal facies is similar, and the accumulating environment of peat swamp controlls the contents and the occurrence of minerals, and thus controll the coal washability. The washability or the stratified coal formed in high peat swamp is better than that formed in low peat swamp.

Rational design and evaluation of UV curable nano-silver ink applied in highly conductive textile-based electrodes and flexible silver-zinc batteries

The possibility of printing conductive ink on textiles is progressively researched due to its potential benefits in manufacturing functional wearable electronics and improving wearing comfort.However,few studies have reported the effect of conductive ink formulation on electrodes directly screen-printed on flexible substrates,especially printing UV curable conductive ink on common textiles.In this work,a novel UV curable nano-silver ink with short-time curing and low temperature features was developed to manufacture the fully flexible and washable textile-based electrodes by screen printing.The aim of this study was to determine the influence of ink formulation on UV-curing speed,degree of conversion,morphology and electrical properties of printed electrodes.Besides,the application demonstration was highlighted.The curing speed and adhesion of ink was found depending dominantly on the type of prepolymer and the functionality of monomer,and the type of photoinitiator had a decisive effect on the curing speed,degree of double bond conversion and morphology of printed patterns.The nano-silver content is key to guarantee the suitable screen-printability of conductive ink and therefore the uniformity and high conductivity of textile-based electrodes.Optimally,an ink formulation with 60 wt%nano-silver meets the potential application requirements.The electrode with 1.0 mm width showed significantly high electrical conductivity of 2.47×10^(6)S/m,outstanding mechanical durability and satisfactory washability.The high-performance of electrodes screen-printed on different fabrics proved the feasibility and utility of UV curable nano-silver ink.In addition,the application potential of the conductive ink in fabricating electronic textiles(e-textiles)was confirmed by using the textile-based electrodes as the cathodes of silverzinc batteries.We anticipate the developed UV curable conductive ink for screen-printing on textiles can provide a novel design opportunity for flexible and wearable e-textile applications.