Carbon fiber yarns（CFY） are promising as a new type of flexible building blocks for the construction of flexible architectures for the energy storage applications. The main hurdle with CFY is how to make them high e...Carbon fiber yarns（CFY） are promising as a new type of flexible building blocks for the construction of flexible architectures for the energy storage applications. The main hurdle with CFY is how to make them high energy and power capable by using economically and environmentally viable materials. Here,we report reduced graphene oxide（r GO） and Prussian blue（PB） coated CFY, derived from a facile electrochemical process at room temperature for supercapacitor electrodes. The PB coated CFY and r GO coated CFY electrodes exhibit the excellent gravimetric capacitance of 339 F/g and 160.2 F/g, respectively, in aqueous KCl electrolyte in three-electrode cell configuration. When we coupled these electrodes inside the flexible plastic tube and separated by the electrolyte wet filter paper in order to construct flexible architecture, the resulting device delivers excellent specific energy of 52.1 Wh/kg and 26.5 Wh/kg with offering specific power of 3100 W/kg and 14400 W/kg respectively, under a wide operating potential of1.8 V with excellent rate capability. The device shows high tolerance towards bending, and retained its efficiency to the capacitance after being bent at an angle of 360° for 200 bending cycles.展开更多
Fabrication of electrically conductive yarns(glass,flax and polypropylene fibers)coated with graphene nanoparticles(GNP)were characterized for their mechanical properties and compared with their electrical properties....Fabrication of electrically conductive yarns(glass,flax and polypropylene fibers)coated with graphene nanoparticles(GNP)were characterized for their mechanical properties and compared with their electrical properties.The composites were produced with the use of polymeric binders(epoxy resin and thermoplastic starch)and two different dipcoating methodologies were developed to create the coating layers.Technique-1 involved coating of binder and then GNP layer whereas Technique-2 had a mixture of binder and GNP in the predetermined ratio,which was coated on the yarns.The mechanism of adhesion varies or influences on a number of factors such as the nature of the fiber surface,coating method and effective binder.Tensile properties of the yarns were measured by an appropriate standard,and the highest tensile strength was noticed with epoxy-based glass fiber samples as 222 MPa followed by flax fiber samples as 206 MPa.The composites of starch-based showed poor mechanical performance compared to those of epoxy ones.This was due to poor adhesion between the surface and starch layer(interphase)where the Van der Wall’s force was quite low.Electrical conductivity,glass fiber yarns with epoxy binder were identified to have the highest electrical conductivity of 0.1 S.cm−1 among other samples.展开更多
This article is devoted to the research work aimed at improving the quality of yarns obtained by pneumomechanical spinning. The yarn quality indicators obtained at different speed modes of the pneumomechanical spinnin...This article is devoted to the research work aimed at improving the quality of yarns obtained by pneumomechanical spinning. The yarn quality indicators obtained at different speed modes of the pneumomechanical spinning machine discrete drum were studied and analyzed. The effect of the number of incisions of the sawtooth coatings on the discrete drum on the quality indicators of the yarn produced was also studied. The results of the experiments were analyzed by graphical and histogram methods, and alternative options were suggested.展开更多
Consolidation of thermoplastic unidirectional(UD)lami-nate with friction spun core yarns was investigated,espe-cially the characterization of filament bundles in consoli-dation was analyzed.The results showed that the...Consolidation of thermoplastic unidirectional(UD)lami-nate with friction spun core yarns was investigated,espe-cially the characterization of filament bundles in consoli-dation was analyzed.The results showed that the bundleeffect was affected considerably by processing conditions(applied pressure and processing time).The boundaryof the bundles was disappeared under suitable processingconditions and finally an even fiber/resin distributioncould be attained.In consolidation,filament bundlesgetting close each other and resin flowing into the bundl-es occurred simultaneously,and eventually the bundleswere fully impregnated by the resin.Fiber packing den-sity in UD-laminate was the same as that of frictionspun core yarn(55%-65% in volume)and was not af-fected significantly by processing conditions under thecurrent experimental conditions.展开更多
基金CNPq, Govt. of Brazil for providing financial support under the scheme of Science without Border to carry out this research work
文摘Carbon fiber yarns（CFY） are promising as a new type of flexible building blocks for the construction of flexible architectures for the energy storage applications. The main hurdle with CFY is how to make them high energy and power capable by using economically and environmentally viable materials. Here,we report reduced graphene oxide（r GO） and Prussian blue（PB） coated CFY, derived from a facile electrochemical process at room temperature for supercapacitor electrodes. The PB coated CFY and r GO coated CFY electrodes exhibit the excellent gravimetric capacitance of 339 F/g and 160.2 F/g, respectively, in aqueous KCl electrolyte in three-electrode cell configuration. When we coupled these electrodes inside the flexible plastic tube and separated by the electrolyte wet filter paper in order to construct flexible architecture, the resulting device delivers excellent specific energy of 52.1 Wh/kg and 26.5 Wh/kg with offering specific power of 3100 W/kg and 14400 W/kg respectively, under a wide operating potential of1.8 V with excellent rate capability. The device shows high tolerance towards bending, and retained its efficiency to the capacitance after being bent at an angle of 360° for 200 bending cycles.
基金supported by the Ministry of Business,Innovation and Employment New Zealand[UOAX1415].
文摘Fabrication of electrically conductive yarns(glass,flax and polypropylene fibers)coated with graphene nanoparticles(GNP)were characterized for their mechanical properties and compared with their electrical properties.The composites were produced with the use of polymeric binders(epoxy resin and thermoplastic starch)and two different dipcoating methodologies were developed to create the coating layers.Technique-1 involved coating of binder and then GNP layer whereas Technique-2 had a mixture of binder and GNP in the predetermined ratio,which was coated on the yarns.The mechanism of adhesion varies or influences on a number of factors such as the nature of the fiber surface,coating method and effective binder.Tensile properties of the yarns were measured by an appropriate standard,and the highest tensile strength was noticed with epoxy-based glass fiber samples as 222 MPa followed by flax fiber samples as 206 MPa.The composites of starch-based showed poor mechanical performance compared to those of epoxy ones.This was due to poor adhesion between the surface and starch layer(interphase)where the Van der Wall’s force was quite low.Electrical conductivity,glass fiber yarns with epoxy binder were identified to have the highest electrical conductivity of 0.1 S.cm−1 among other samples.
文摘This article is devoted to the research work aimed at improving the quality of yarns obtained by pneumomechanical spinning. The yarn quality indicators obtained at different speed modes of the pneumomechanical spinning machine discrete drum were studied and analyzed. The effect of the number of incisions of the sawtooth coatings on the discrete drum on the quality indicators of the yarn produced was also studied. The results of the experiments were analyzed by graphical and histogram methods, and alternative options were suggested.
文摘Consolidation of thermoplastic unidirectional(UD)lami-nate with friction spun core yarns was investigated,espe-cially the characterization of filament bundles in consoli-dation was analyzed.The results showed that the bundleeffect was affected considerably by processing conditions(applied pressure and processing time).The boundaryof the bundles was disappeared under suitable processingconditions and finally an even fiber/resin distributioncould be attained.In consolidation,filament bundlesgetting close each other and resin flowing into the bundl-es occurred simultaneously,and eventually the bundleswere fully impregnated by the resin.Fiber packing den-sity in UD-laminate was the same as that of frictionspun core yarn(55%-65% in volume)and was not af-fected significantly by processing conditions under thecurrent experimental conditions.
