Preparation of a wearable K-PAN@CuS composite fabric with excellent photothermal/electrothermal properties

Electrospun nanofibers with highly efficient photothermal/electrothermal performance are extremely popular because of their great potential in wearable heaters.However,the lack of necessary wearable properties such as high mechanical strength and quick response of electrospun micro/nanofibers seriously affects their practical application.In this work,a technical route combining electrospinning and surface modification technology is proposed.The 3-triethoxysilylpropylamine-polyacrylonitrile@copper sulfide(K-PAN@CuS)composite fabric was achieved by modifying the original electrospinning PAN fiber and subsequently loading CuS nanoparticles.The results show that the break strength of the K-PAN@CuS fabric was increased by 10 times compared to that of the original PAN@CuS fabric.Furthermore,the saturated temperature of the K-PAN@CuS fabric heater could reach 116℃within 15 s at a relatively low voltage of 3 V and 120.3℃within 10 s under an infrared therapy lamp(100 W).In addition,due to its excellent conductivity,such a unique structural design enables the fiber to be closely attached to the human skin and helps to monitor human movements.This K-PAN@CuS fabric shows great potential in wearable heaters,hyperthermia,all-weather thermal management,and in vitro physical therapy.

Integratingmultiple energy storage in 1D–2D bridged array carbon-based phase change materials

In response to global energy scarcity,frontiers in multifunctional composite phase change materials(PCMs)with photo-/electro-/magnetothermal triggers show great potential in multiple energy utilization.However,most available composite PCM candidates are inadequate for multiple energy storage applications simultaneously.Herein,a green synthetic route is proposed to develop bimetallic zeolitic imidazolate framework(ZIF)-derived 1D–2D bridged array carbon-based composite PCMs for simultaneous photo-/electro-/magnetothermal energy storage applications.As graphitization-induced catalyst,Co nanoparticles greatly boost the formation of ZIF-derived 1D–2D bridged array carbon framework with high graphitization and low interface electrical/thermal resistance.Benefiting from the broadband intense photon capture,fast photon/electron/phonon transport,and surface plasma resonance effect of Co nanoparticles,the resulting composite PCMs integrate advanced photo-,electro-,and magnetothermal storage functions.Furthermore,composite PCMs also exhibit long-lasting shape stability,structural stability,thermal storage stability,and photo-/electro-/magnetothermal storage stability after undergoing multiple heating–cooling cycles.This study is promising to accelerate the major breakthroughs of advanced multifunctional carbon-based composite PCMs toward multiple energy utilization.

Multifunctional Ti_(3)C_(2)T_(x)-(Fe_(3)O_(4)/polyimide)composite films with Janus structure for outstanding electromagnetic interference shielding and superior visual thermal management

Flexible multifunctional polymer-based electromagnetic interference(EMI)shielding composite films have important application values in the fields of 5G communication technology,wearable electronic devices and artificial intelligence.In this work,Fe_(3)O_(4)/polyamic acid(PAA)nanofiber films are prepared by in-situ polymerization and electrospinning technology,and Ti_(3)C_(2)T_(x)nanosheets are deposited on the surface of the Fe_(3)O_(4)/PAA nanofiber films via vacuum-assisted filtration.Then,Janus Ti_(3)C_(2)T_(x)-(Fe_(3)O_(4)/polyimide(PI))composite films are obtained by thermal imidization.The two sides of the Janus films exhibit completely different properties.The Fe_(3)O_(4)/PI side has excellent hydrophobicity and insulation property,and the Ti_(3)C_(2)T_(x)side has hydrophilicity and terrific conductivity.When the mass fraction of Ti_(3)C_(2)T_(x)is 80 wt.%,the Janus Ti_(3)C_(2)T_(x)-(Fe_(3)O_(4)/PI)composite film has excellent EMI shielding performances and mechanical properties,with EMI shielding effectiveness,tensile strength and Young’s modulus reaching 66 dB,114.5 MPa and 5.8 GPa,respectively.At the same time,electromagnetic waves show different absorption shielding effectiveness(SEA)when incident from two sides of the Janus films.When the electromagnetic waves are incident from the Fe_(3)O_(4)/PI side,the SEA of the Janus film is 58 dB,much higher than that when the electromagnetic waves are incident from the Ti_(3)C_(2)T_(x)side(39 dB).In addition,the Ti_(3)C_(2)T_(x)side of the Janus Ti_(3)C_(2)T_(x)-(Fe_(3)O_(4)/PI)composite films also has excellent electrothermal and photothermal conversion performances.When the applied voltage is 4 V,the stable surface temperature reaches 108°C;when it is irradiated by simulated sunlight with power density of 200 mW/cm2,the stable surface temperature reaches 95℃.

Multistimuli Responsive and Thermoregulated Capability of Coaxial Electrospun Membranes with Core-sheath Structure and Functional Polypyrrole Layer

Developing thermal management fabrics with good energy storage and multistimuli responsive properties is important for regulating the body temperature in complex environment.Herein,the intelligent nonwoven membranes were fabricated via a coaxial electrospinning method,resulting in a core-sheath structure with poly(ethylene glycol)(PEG)as core and polyurethane(PU)as sheath.Additionally,polypyrrole(PPy)with good light absorption ability and electrical conductivity was deposited onto the surface of the PU@PEG electrospun fibers via electrochemical polymerization.The PPy layer enabled the membranes to respond quickly to sunlight and electrical stimuli.The membranes could heat up to 86°C under simulated sunlight within 200 s or produce remarkable electrothermal effect under a low voltage input of only 1V,exhibiting efficient energy conversion and storage performances.The photothermal and electrothermal conversion effect could be easily adjusted by controlling the polymerization time of PPy.Therefore,the multifunctional membranes with high latent heat,good mechanical properties as well as excellent photothermal/electrothermal conversion ability are promising in personal thermal management applications.