Study On Preparation And Properties Of Dye-doped Conductive Polymer Composites

Conductive polymers have attracted much attention due to their wide applications,among which polyaniline and polypyrrole are the most popular research hotspots.Simple conductive polymer materials have some problems,such as poor conductivity,insoluble and refractory,which limit their application.Dye molecules,as anion dopants,are perpendicular to the polymer chains,which is conducive to mass transfer of polymer membranes and improve the ordering degree of molecular chains.Acidic dyes,such as acid fuchsin(AF),have solubilizing groups such as sulfonate,which can be used as anionic dopants and structural guidance agents in monomer polymerization,thus regulating the micro-morphology of conductive polymers and improving their conductivity.The main contents of this paper are as follows:(1)Polypyrrole(PPy)and polyaniline(PANI)conductive polymers were prepared by chemical oxidation polymerization with ferric chloride(FeCl3)as oxidant.The products were characterized by scanning electron microscopy(SEM),Fourier transform infrared spectroscopy(FT-IR),X-ray diffraction(XRD)and four-probe resistance measurement.(2)AF-PPy composites were synthesized by chemical oxidation using acid dye AF as anion dopant and FeCl3 as oxidant.The composites of AF,PPy and AF-PPy were characterized by SEM,FT-IR,XRD and electrical resistance.At the same time,the effects of AF concentration,oxidant type and concentration,doping acid concentration,reaction time and reaction temperature on the micro-morphology and electrical conductivity of AF-PPy composites were discussed by single factor analysis,controlling experimental conditions and changing experimental parameters.The formation mechanism of AF-PPy composites with special morphology was speculated.(3)AF-PPy and AF-PANI composites were synthesized by chemical oxidation with acid dye AF as anion dopant and FeCl3 as oxidant under the same experimental environment and conditions.At the same time,the molar ratios of AF-monomer(Py/ANl)and FeCl3-monomer(Py/ANI)were changed to investigate the different effects of dopant and oxidant concentration on their micro-morphology and conductivity,and to compare the two.In addition,phosphoric acid(H3PO4)was added as doping acid,and its relative content in the polymerization system was changed.The effect of H3PO4 on the electrical conductivity of AF-PANI composites was discussed.