Preparation And Some Applications Of Conductive Polypyrrole

Pyrrole is one of a five-membered heterocyclic compounds containing nitrogen.After a process of oxidation and polymerization,it will shape to polyyrrole,which has conductivity and chemical stability.It has the characteristics of easy oxidation polymerization,good water solubility and non-toxic.Therefore,Polyyrrole has a broad application prospect in plastic substrate,electrocatalysis,display devices,metal anti-corrosion coatings for light-emitting devices,supercapacitors,etc.This thesis mainly studies the synthesis and application of polypyrrole in two aspects:the conductive treatment of polypyrrole on plastic substrate and the synthesis of polypyrrole for supercapacitor.（1）Starting from the application of conductive polypyrrole in conductive treatment of PCB plastic substrate,the growth of polypyrrole film on the substrate and copper electroplating after coating were studied by chemical oxidation polymerization under different film forming conditions.It is found that the forming conditions of film have a significant effect on its uniformity and conductivity,and the appropriate concentration is conducive for it to obtaining a uniform polypyrrole film on the plastic substrate.Through optimization,when ethanol is used as solvent,the volume ratio of pyrrole to ethanol is 1:2,the concentration of ferric chloride is 1mol/L,the reaction temperature is 0℃,and the reaction time is 5min,the conductive polypyrrole film formed on the surface of the epoxy resin substrate has the best conductivity.The copper layer on the film is evenly distributed,and the copper grains are in the form of microspheres.（2）Explore the situation of polypyrrole inducing chemical copper deposition on PCB plastic substrate,and explore a new palladium free chemical copper deposition process.In this process,the authors used polypyrrole to induce copper for palladium-free chemical precipitation on a plastic substrate.When the substrate is immersed in copper precipitation solution for 0.5 h,copper grains begin to appear on the substrate,and spread over the entire substrate surface in about 2 hours.The electroless copper deposition on the surface of non-conductive plastic substrate is realized,which replaces the precious metals,solves the problem of difficult treatment of precious metal catalytic reaction waste liquid,and reduces the cost of production.（3）The formation mechanism of spherical silver doped polypyrrole composite was studied by chemical redox reaction in the solution of pyrrole monomer,silver nitrate,trisodium citrate and ferric chloride.First,when all starting substances,including citric acid ions,are mixed together,a negatively charged[Ag₃（C₆H₅O₇）_n+1]^3n-complex is produced,which becomes the initial active site for polypyrrole nucleation.Then,when ferric chloride is added,pyrrole will quickly be oxidized to polypyrrole,and negatively charged[AgCl _x+1]^x-micelles will be shaped by the combination of chloride ions and Ag⁺,which are the core of spherical polypyrrole growth and induce the growth of polypyrrole.At the end of the reaction,the author uses strong alkaline ammonia to remove insoluble silver chloride particles,and promotes C₆H₅O₇^3-reduced Ag⁺to be elemental silver.As a result,it forms to a single spherical nano particle PPy-Ag composite with smooth and regular surface and consistent particle size.