Conducting Polymer Nanocomposites Prepared By Chemical Vapor-phase Polymerization Method

Based on the further investigation of conducting polymer and its composites, conducting polymer nanocomposites has been showed obvious advantages in the fields of electrochemistry and sensitive materials. In this thesis, poly-3,4-ethylenedioxythiophene(PEDOT) as a matrix material, the study focused on the synthesis and properties of PEDOT and its nanocomposites to evaluate their potentia applications. A chemical vapor-phase polymerization(VPP) method was employed to prepare PEDOT and its nanocomposites with graphene, graphene oxide and Ag nanoparticles. The conductive, electrochemical and gas sensitive properties of PEDOT and its nanocomposites were studied in detailed. The main results are as follows:1. A chemical vapor-phase polymerization(VPP) method was employed to prepare conducting PEDOT films. The optimized synthesis process was investigated for better PEDOT film performance. The conducive results showed that The conductivity of the VPP film increases with the enhancement of exposed time and obtains maximum conductivity after the polymerization of EDOT in oxidant films for 1–2 h, and PEDOT films exhibited maximum conductivity ca. 17.3 S/cm.2. The VPP method was employed to prepare conducting composite poly-3,4-ethylenedioxythiophene(PEDOT)/reduced graphene oxide(RGO) film. The samples to be covered with PEDOT are initially coated with a thin layer of oxidant/GO, and this modifying films was transferred to a VPP chamber containing 3,4-ethylenedioxythiophene monomer gas for chemical polymerization. The latter formed PEDOT/GO film was then treated by glucose and highly conductive PEDOT/RGO films was obtained. The conducive results showed that PEDOT/RGO films exhibited conductivity ca. 35.3 S/cm, which higher than pure PEDOT(17.3 S/cm) and PEDOT/GO(14.6 S/cm) films. The PEDOT/RGO films showed specific capacitance ca. 114.4 F/g and kept 84% initial capacitance after 800 cycles, indicating excellent specific capacitance and cycling stability performance.3. The VPP method was employed to prepare poly-3,4-ethylenedioxythiophene/Ag nanoparticle film. The conducive results showed that PEDOT/Ag films exhibited conductivity ca. 54.8 S/cm, which higher than pure PEDOT(17.3 S/cm) films.The presence of Ag nanoparticles in the PEDOT/Ag composite may largely reduce the conductive resistance, leading to the observed good capacitive behavior. The PEDOT/Ag films showed specific capacitance ca. 100.3 F/g and kept 80.5% initial capacitance after 1000 cycles, indicating excellent specific capacitance and cycling stability performance.4. The ultrathin reduced graphene oxide(RGO) layer was prepared by Langmuir-Blodgett(LB) deposition and the following water steam treatment, and a ultrathin PEDOT layer was constructed on RGO surface through VPP process. The gas-sensing properties and related mechanism of PEDOT/RGO LB film to NO2 gas was explored. The result show that the conducting polymer nanocomposite film exhibited a excellent response and recovery charzcteristics to the NO2 gas.