Properties of PAn/PVA Conducting Composite Film by Electrochemical Polymerization

The polyaniline (PAn)/poly(vinyl alcohol) (PVA) conductive composite film is synthesized with perchloric acid (HClO 4) as the dopant and oxidant in reaction system by electrochemical polymerization. The result shows that this composite film has very high conductive properties, the maximum value of conductivity reaches 0.173 S/cm at the concentration 0.75 mol. The influences of HClO 4 on the conductivity of the composite film are investigated.In addition,the electrode reaction progress is discussed with the result that obtained from SEM and FTIR analyzing.

Janus(BNNS/ANF)-(AgNWs/ANF)thermal conductivity composite films with superior electromagnetic interference shielding and Joule heating performances

Highly thermal conductivity materials with excellent electromagnetic interference shielding and Joule heating performances are ideal for thermal management in the next generation of communication industry,artificial intelligence and wearable electronics.In this work,silver nanowires(AgNWs)are prepared using silver nitrate as the silver source and ethylene glycol as the solvent and reducing agent,and boron nitride(BN)is performed to prepare BN nanosheets(BNNS)with the help of isopropyl alcohol and ultrasonication-assisted peeling method,which are compounded with aramid nanofibers(ANF)prepared by chemical dissociation,respectively,and the(BNNS/ANF)-(AgNWs/ANF)thermal conductivity and electromagnetic interference shielding composite films with Janus structures are prepared by the"vacuum-assisted filtration and hot-pressing"method.Janus(BNNS/ANF)-(AgNWs/ANF)composite films exhibit"one side insulating,one side conducting"performance,the surface resistivity of the BNNS/ANF surface is 4.7×10^(13) Ω,while the conductivity of the AgNWs/ANF surface is 5,275 S/cm.And Janus(BNNS/ANF)-(AgNWs/ANF)composite film with thickness of 95 pm has a high in-plane thermal conductivity coefficient of 8.12 W/(m·K)and superior electromagnetic interference shielding effectiveness of 70 dB.The obtained composite film also has excellent tensile strength of 122.9 MPa and tensile modulus and 2.7 GPa.It also has good temperature-voltage response characteristics(high Joule heating temperature at low supply voltage(5 V,215.0℃),fast response time(10 s)),excellent electrical stability and reliability(stable and constant real-time relative resistance under up to 300 cycles and 1,500 s of tensile-bending fatigue work tests).

Silk Fibroin Based Conductive Film for Multifunctional Sensing and Energy Harvesting

Development of biomaterial based flexible electronics has got intensive attention owing to the potential applications in the wearable and epidermal devices.Silk fibroin,as a natural textile material with excellent performance,has been widely concerned by industry and academy.However,the property of electrical insulation limits his development in the field of flexible electronics.In this paper,a regenerated silk fibroin/carbon nanotube(RSF/CNT)conductive film has been successfully fabricated and applied in flexible capacitive-type pressure sensor and wearable triboelectric nanogenerator by a facile method.The electrical conductivity and mechanical property of RSF/CNT film was optimized by investigating with different composite ratio from 10 to 90%(W_(RSF)/W_(CNT)).The RSF/CNT film has a good photothermal response and electric heating performance.We furtherly demonstrated that the RSF/CNT based sensor can be used as epidermal self-powered sensor for multifunction human motion monitoring and Morse code compilation.The observed research results have shown that the RSF/CNT film has a wide range of potential application prospects in the wearable electronics field.

Neurogenic differentiation of human umbilical cord mesenchymal stem cells on aligned electrospun polypyrrole/ polylactide composite nanofibers with electrical stimulation

Adult central nervous system （CNS） tissue has a limited capacity to recover after trauma or disease. Recent medical cell therapy using polymeric biomaterial- loaded stem cells with the capability of differentiation to specific neural population has directed focuses toward the recovery of CNS. Fibers that can provide topographical, biochemical and electrical cues would be attractive for directing the differentiation of stem cells into electro-responsive cells such as neuronal cells. Here we report on the fabrication of an electrospun polypyrrole/polylactide composite nanofiber film that direct or determine the fate of mesenchymal stem cells （MSCs）, via combination of aligned surface topography, and electrical stimulation （ES）. The surface morphology, mechanical properties and electric properties of the film were characterized. Comparing with that on random surface film, expression of neurofilament-lowest and nestin of human umbilical cord mesenchymal stem cells （huMSCs） cultured on film with aligned surface topography and ES were obviously enhanced. These results suggest that aligned topography combining with ES facilitates the neurogenic differentiation of huMSCs and the aligned conductive film can act as a potential nerve scaffold.