The Preparation And Characterization Of Conducting Polymer/Inorganic Nanoparticle Modified Composite Fabrics

Polyaniline（PANI） is one of the most investigated conducting polymers（CP）.It has been frequently studied due to its low cost,ease in preparation,good enviromnental stabilities,and high conductivity.Though,PANI has fine electrical dissipation,its conductivity is relative lower than metals.In order to enhance materials’ conductivity and expand other functions,the polyaniline is usually combined with inorganic nanoparticles to prepare novel composite materials which not only have higher conductivity,but also have special functions such as water proof,UV-blocking and anti bacterial properties.So these new composite materials can satisfy people’s higher electromagnetic interference shielding and antistatic requirements.In this paper,the PANI/nano ZnO composite films deposited on PET fabric surface were prepared by fractional step method.Firstly,the basic properties of PANI films on PET fabric surface were investigated.On base of the experimental data,the reaction parameters including concentration of dopants and oxidants,immersing time,temperature of oxidants and wet pickup （%） which influence the conductivity of PANI films were studied in detail.The optimum conditions for preparing high conductivity polyaniline composite PET fabrics were as follows:the concentration of dopants and oxidants was 0.2mol/L,immersing time was 5s,temperature of oxidants was below 40℃and wet pickup was controlled at 120%.Otherwise,the effects of curing temperature and inorganic doping acids on conductivity and structure of polyaniline deposited on fabric surface were also investigated in detail by FTIR,XRD and FE-SEM.Secondly,the ZnO nanoerystals were synthesized by sol-gel method and then coated onto PET substrates by dip-pad-cure process as nucleation seeds,followed by hydrothermal ZnO growth in aqueous solution of zinc nitrate and hexamethylenetetramine.Under growth condition of c[Zn（NO₃）₂]=0.03mol/L,n(C₆H₁₂N₄):n[Zn（NO₃）₂]=1:1,T=90℃,t=3h,the well-aligned ZnO nanorod arrays with 40-50nm in diameter and 300-500nm in length were achieved on the pre-treated PET fabrics.XRD result indicated the as-prepared nanorods were of high quality and defect free with hexagonal wurtzite ZnO structure and its growth direction is along the c-axis.Finally,using nano ZnO/PET composite fabric as substrate,PANI/nano ZnO composite films were directly deposited on PET fabrics by modified in-situ chemical polymerization under optimum conditions.By means of the thermodynamic analysis,it was found that the ZnO nanorods grown on fabric surface were in favor of the fibers to absorb more aniline,and the aniline molecules were more strongly absorbed onto PET fibers with the quantity of ZnO increasing.In the process of forming PANI/nano ZnO composite films,ZnO nanorods acted as backbone and helped to combine the polymers.FE-SEM,XRD and AFM were used to observe and analyze the morphology and structure of the composite films.It could be found that,after polymerization,the polyaniline generated around the nanorods and formed continuous and uniform conductive layer on fabric surface.XRD spectrum showed the nano ZnO in composite films could help to improve orderliness of PANI molecular chains as well as decrease defects of PANI’s structure.The PANI/nano ZnO conducting composite fabrics obtained in this study displayed excellent electrical conductivity and surface specific conductivity（ρ_s） reduced to 5.23×10²Ω.Moreover,the composite fabrics also showed favorable thermal stability.