Preparation And Properties Of Carbon Nano Materials/PANI/EVOH Nanofiber Composite Film

Portable and wearable electronic devices are more important with the dedevelopment of our society,also the flexible electrode material is core.Carbon nanotubes(CNTs),graphene(GR)and polyaniline(PANI)as new materials,its specific properties making them a kind excellent material of supercapacitor electrode.Carbon nanomaterial/PANI composite electrode has a great electrochemical performance,but its flexibility and mechanical strength are not good enough,so it can't be used to the flexible super-capacitor.Polyethylene-co-polyvinyl alcohol(EVOH)nanofiber as a common thermoplastic polymer,its specific properties of large surface area,high length-diameter ratio,small aperture and good flexible making it a kind promsing material for flexible electrode.Then EVOH nanofiber was added into the PANI/CNTs and PANI/graphene composite materials,acting as flexible substrate.Scanning Electron Microscopy(SEM),Raman Spectrometer(Raman),Wide-Angle X-ray Diffraction(WAXD),Thermal Gravimetric Analysis(TGA),mechanical properties test and electrochemical performance test.The main contents and conclusions of the research are as follows:Firstly,by in situ oxidation polymerization of PANI to prepare CNTs/PANI/EVOH(CPE)nanofiber composite film.The results showed that its surface morphology is relatively uniform,with a large number of PANI adsorpting on the surface of the nanofibers and CNTs.the PANI growth relatively orderly,with the increase of nanofiber content,specific surface area and average pore diameter increases first and then decreases.What's more,its flexibility,thermal stability and mechanical properties were enhanced at the same time.Furthermore,the conductivity of members is decreased,CPE20% has the highest conductivity in the condition of creating film,which is 3.0 S/cm.Secondly,by in situ oxidation polymerization of PANI to prepare RGO/PANI/EVOH(RPE)nanofiber composite film.The results showed that the morphology of composite membrane is relatively uniform,because the polyaniline is more easily adsorbed on the graphene.Compared with CPE composite film,its mechanical properties and flexibility were largely improved.RPE15% has the highest conductivity and specific capacitance,2.3 S/cm and 56.4 F/g.Comprehensive consideration,we can choose RPE15% composite film as flexible super capacitor electrode.Finally,to discuss the influence of different kinds and concentrations of oxidizing agent and mixed acid for the conductivity and electrochemical properties of RPE15% composite film.The kinds and concentrations of oxidizing agent were the most important factors.RPE with no oxidizing agent and 4.0 mol/L HCl-doped has the highest conductivity,13.0 S/cm.GO can act as an oxidizing agent in the polymerization process because its oxygen containing functional groups,so RPE composite film need not to reduced again to avoid the passivation of polyaniline and improve the specific capacitance.The electrochemical performance of RPE without oxidizing agent is best,under 5 m V/s sweep speed,the quality of the capacitance reached 92.7 F/g,capacitance retention rate is 80.1% after 650 cycles.The study of different systems revealed that introduced EVOH nanofiber to the system of carbon nanomaterial/PANI can improve the flexibility of the composite electrode and contain the electrochemical performance.