Preparation And Characterization Of Conductive Polyaniline Composite Membranes

The conductive membranes have the advantages of softness and conductivity.It has been used in molecular circuits,capacitors,gas sensors,filter materials and safety clothing for the application potential of electronic,biological,environmental and textile fields.Polyaniline is a typical conductive polymer which have good properties of high conductivity can be doped,environmental stability.It also has the advantages of simple synthesis and low cost.Therefore,it is of great theoretical and practical significance to prepare conductive fiber membranes.Polyaniline and graphene composite have synergistic effect,not only improve the conductivity,but also make up for the shortcomings of a single material.Therefore,polyaniline,polyaniline/graphene films were prepared by in-situ polymerization in this paper.Then Polyaniline and polyaniline polyaniline/graphene fiber membranes were prepared by electrospinning.The specific research contents are as follows:(1)Polyaniline/polyvinyl alcohol(PANI/PVA)films were prepared by emulsion polymerization and spin coating which used PVA as the main film-forming substance.In this paper,the effects of oxidant(APS),doped acid(DBSA)and film-forming agent(PVA)on the conductivity of PANI films were studied,and the optimal synthesis parameters of PANI films were obtained.The results show that when the molar ratio of synthetic materials(DBSA:An:APS)is 0.75:1:0.75,the conductivity of the synthesized PANI film is the largest and reaches 0.75 S/cm.(2)In order to improve the electrical conductivity of the polyaniline film,polyaniline/reduced graphene oxide/polyvinyl alcohol(PANI/RGO/PVA)composite film were prepared by emulsion polymerization and spin coating.The effects of RGO concentration on the morphology,chemical structure,crystallinity and electrochromic properties of the composite films were studied.Graphene and its derivatives have excellent electrical conductivity.Therefore,the addition of RGO can improve the electrical and chemical properties of PANI/RGO composite films The results show that as the RGO concentration increases from 0.1 wt% to 0.25 wt%,the conductivity of the PANI/RGO/PVA composite film increases,and the highest conductivity is 3.57 S/cm.PANI/RGO/PVA composites film have a wider range of colors from green to black than the PANI film from green to dark blue electrochromic range.(3)In order to further improve the specific surface area of polyaniline,PANI/PVA and PANI/RGO/PVA composite fiber membranes were prepared by electrospinning.The experimental results show that when the concentration of RGO is 0.2%,the diameter distribution of PANI/GRO/PVA nanofibers is uniform,and there are no particles and droplets adhere on PANI/GRO/PVA nanofibers.A large specific surface area was formed which can provide sufficient passage for the transport of ions.The PANI/RGO/PVA fiber nanofibers has a higher specific capacitance value of 174 F/g than the electrode of the PANI/PVA nanofibers of 105 F/g.(4)The PANI/GRO/PVA fiber nanofibers with RGO concentration of 0.2% was assembled into an aqueous capacitor.The specific capacitance of the nanofiber capacitor was 5.2,20.2,50.6,100.3,303,and 466.397 F/g at different current densities of 0.1,0.2,0.4,0.6,0.8,1.0 A/g.After 1500 cycles of charge and discharge,the specific capacity retention rates were 82.5%.It is shown that the nanofiber electrode significantly increases the specific capacitance of the supercapacitor.