| Polymer-based dielectric composites have broad application prospects in the fields of microelectronics and dielectric energy storage.Polyvinylidene fluoride?PVDF?has the advantages of excellent dielectric properties,high breakdown,and low cost.Improving its dielectric properties can expand its range of applications.Generally,conductive materials are added to the PVDF matrix to increase its dielectric constant.Due to the good compatibility between the PVDF matrix and the conductive materials,the composites produced also have good flexibility and are often used as high-performance flexible electronic devices and Flexible energy storage materials.The conductive material silver nanowires?Ag NWs?is often used as a filler to increase the dielectric constant of polymer-based composites.Ag NWs is designed as a core-shell structure Ag NWs@PANI.Ag NWs@PANI/PVDF flexible composites are prepared under different process conditions.material.In this paper,polyvinylidene fluoride?PVDF?was selected as the polymer matrix.Ag NWs were prepared by the polyol method.Ag NWs were surface-coated with polyaniline by the in-situ polymerization method to prepare Ag NWs@PANI with a core-shell structure.Ag NWs@PANI and PVDF were used to make composite glue solution.Ag NWs@PANI/PVDF electrospun membrane was prepared by electrospinning technology.The electrospun membrane was hot-pressed to obtain Ag NWs@PANI/PVDF flexible composite material.Ag NWs@PANI/PVDF flexible composites doped under different acid concentrations.X-ray diffractometer?XRD?,infrared spectrometer?FTIR?,scanning electron microscope?SEM?,transmission electron microscope?TEM?were used to characterize Ag NWs,Ag NWs@PANI and Ag NWs@PANI/PVDF electrospun membranes and to characterize flexible composites The dielectric constant,dielectric loss,and electrical conductivity of the material were tested and analyzed.The results show that Ag NWs with a purity of about 30 um,a diameter of about 15 nm,and an aspect ratio of about 200 are successfully prepared.The uniform thickness of PANI was successfully coated on the Ag NWs surface,and the coating effect was obvious.The diameter of Ag NWs@PANI/PVDF electrospun fiber filaments is about 400 nm,and Ag NWs@PANI is evenly dispersed into the composite material.When the mass fraction of the filler is 5%and the molar ratio of the oxidant ammonium persulfate and aniline is 1?APS/An=1?,the dielectric constant and dielectric loss are 29 and 0.089,respectively,and the conductivity is 2.62×10-11S/cm.With a filler mass fraction of 5%,hydrochloric acid concentration of 1 mol/L,and the addition of dodecylbenzenesulfonic acid?DBSA?,its dielectric constant and dielectric loss are 31 and 0.15,respectively,and the electrical conductivity is 3.64×10-11 S/cm.In the process of preparing Ag NWs@PANI,the electrical properties of the coating PANI can be improved after the addition of dodecylbenzenesulfonic acid,and the electrical properties of the flexible composite material are improved.When the mass fractions of different fillers are all 5%,the dielectric properties of Ag NWs@PANI/PVDF flexible composites are slightly increased compared to Ag NWs/PVDF and PANI/PVDF composites.With the increase of the filler content,the dielectric constant and dielectric loss of the Ag NWs@PANI/PVDF flexible composite materials have gradually increased.When the filler mass fraction is 20%,the dielectric constant and dielectric loss of the flexible composite material are 43 and 0.22,and the conductivity is 1.63×10-10 S/cm. |
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