Preparation And Functional Properties Of Polyaniline/Carbon Nano-Hybrid Materials

Corrosion of metals can cause huge economic losses,and the use of anti-corrosion coatings to protect metals is one of the effective ways.However,most of the current organic coatings are organic solvent type,which will release a large amount of volatile organic compounds and heavy metal ions,pollute the environment and threaten human safety.On the other hand,in recent years,radio technology has developed rapidly,and the high-frequency electronic devices in the GHz range have been used widely.The electromagnetic interference and electromagnetic wave pollution are also a serious problem.Therefore,it is urgent to develop efficient absorbing materials to solve this problem.Conductive polymer polyaniline(PANi)has the characteristics of simple synthesis,diversified structure,unique doping mechanism,excellent physical and chemical properties,good stability and low raw material price.It has broad application prospects in the field of anti-corrosion and microwave absorption materials.In this work,polyaniline,graphene oxide,graphene and carbon nanotubes were uesd and the polyaniline/carbon-based hybrids were prepared.The anticorrosive properties of polyaniline/graphene-based hybrids and the microwave absorption performance of polyaniline/carbon nanotubes hybrids were studied.The main research work is as follows:(1)The sulfonate group was introduced into the polyaniline molecular chain by the copolymerization method with o-aminobenzenesulfonic acid and aniline as raw materials,and the sulfonated polyaniline(SPANi)with good water solubility was synthesized.Subsequently,the SPANi and graphene oxide(GO)were ultrasonic treated to prepare a sulfonated polyaniline-graphene oxide(SPGO)hybrid material with good water solubility Different amounts of hybrids of SPGO were added to the aqueous epoxy resin matrix to obtain SPGO anticorrosive coating.The content of SPGO has a significant impact on the anti-corrosion performance of waterborne epoxy resins.The results found that when the addition of SPGO hybrids was 0.5%,the obtained anti-corrosion coating has good anti-corrosion performance and the protection efficiency for Q25 steel is 95.81%.(2)Camphorsulfonic acid doped polyaniline-graphene hybrids(CSA/PANi-G)were synthesized by in-situ polymerization.The introduction of camphorsulfonic acid can solve the problem that the PANi is difficult to disperse in water.CSA/PANi-G was added to the waterborne epoxy resin to obtain a CSA-PANi-G modified epoxy resin anticorrosive coating.The content of CSA/PANi-G in the epoxy resin has an important influence on the corrosion protection of the composite.When the CSA/PANi-G content is 0.5%,the electrochemical impedance spectroscopy and Tafel polarization curve test results show that the CSA/PANi-G-0.5% composite coating has the best anti-corrosion effect,and the protection efficiency of Q235 steel can reach 97.43%.(3)The polyvinyl alcohol/polyaniline micelles(P/PANi)with good dispersibility were synthesized by a chemical oxidation method in a hydrochloric acid solution of polyvinyl alcohol.Afterwords,the obtained P/PANi was used as stabilizer and dispersant,and the liquid phase was subjected to ultrasonication to exfoliate the graphene.Based on the ?-? interaction between PANi and graphene,P/PANi-G hybrids were obtained.Then,the obtained P/PANi-G hybrids were added to the aqueous epoxy resin to prepare P/PANi-G epoxy anticorrosive coatings.The results of the potentiodynamic polarization curve and electrochemical impedance spectroscopy of the obtained anticorrosive coating showed that the composites coating containing 0.5% of P/PANi-G filler had excellent corrosion protection and the protection efficiency of Q235 steel is 99.38%.(4)CNTs-bridged graphene nanoribbons can be obtained from longitudinal unzipping of the walls of CNTs by chemical oxidative peeling.At the same time,after the oxidatively peeled CNTs and aniline are polymerized in situ,the microwave absorption capacity of the CNTs@PANi heterostructure can be effectively improved.The optimized 4CNTs@PANi has excellent microwave absorption performance with an RLmin value of-45.7 dB at 12.0 GHz and an effective bandwidth of 10.2 to 14.8 GHz.In addition,the widest effective bandwidth is 5.6 GHz,the coverage is 12.4-18.0 GHz,the thickness is only 2.0 mm,and the minimum reflection loss is-29.0 dB at 14.6 GHz.