Preparation And Characterization Of PPy/Au Nano-composite Material In Microemulsion

Microemulsion is a transparent and thermodynamically stable oil-water dispersed system, which is composed of water, surfactant and cosurfactant. The diameter of dispersed phase in the microemulsion system is ranging from 10nm to 100 nm. Therefore, nano-scale products can usually be obtained by the microemulsion polymerization. These nano-scale products are usually with high molecular weight, narrow particle size distribution and high surface area, which gives the polymerization products excellent performance. Moreover, the polymerization products are dispersed in water and no organic solvent is used, which helps the protection of environment and the conservation of resources. Therefore, the use of microemulsion as reaction medium provides an important way on the synthesis and development of a new material with special properties.After several decades of development, it was found that conductive polymer not only has the characteristics of conductivity, but also has the performance of both the organic polymer materials and the electrical properties of semiconductors and metals. These features and performances make the conductive polymer with a relatively low density, easy to process into complex shapes, good chemical stability, large conductivity range and so on. Compared to other conducting polymer, PPy with conjugated double bonds has gained much attention due to its ease of polymerization, conveniency of making films, good oxidation resistance and high conductivity. Potential applications of PPy include light-emitting materials, electromagnetic shielding materials, secondary batteries, and anti-corrosion coating. However, because of the rigid molecular chain, the processibility of PPy is poor. To overcome the above disadvantage, many efforts are made to composite PPy with plastic materials. Doping or compositing PPy with metals to used to improve the conductivity PPy particles.In this paper, we first studied the phase diagrams of the pseudo-ternary-component about SDS/pyrrole/n-pentanol/water system and found the intervals of microemulsion to prepare the microemulsion of SDS,pyrrole, n-pentanol and water. Then we synthesized PPy particles with KPS as the oxidant and iodine as the dopant. At last, the PPy particles were coated with a layer of soft PMMA shell to prepare PPy-PMMA core-shell nano conductive particles. Through the above modification, the PPy particles were soluable in water and its size was controllable. In addition, the PPy particles prepared above possessed a good processibility and a relatively high conductivity.However, the stability and conductivity of the product should be strengthened. Therefore we composite the conducting polymer with precious metal gold (Au) particles to solve this problem. At the same time, on the basis of core-shell PPy/Au particles, the PMMA soft shell was coated on the surface of PPy/Au composite particles to solve the problem of high rigid and poor processibility and solubility.Two-dimensional transparent conductive film and anti-corrosion coating has been applied widely in our real life and in the military. Therefore, the research of PPy particles with a relatively high conductivity and good processibility has great significance. We dispersed the conducting core-shell polymer in the matrix of PMMA and compressed the samples into pelletes. The transparent conductive film was obtained after the heat treatment. If we dispersed the conducting core-shell polymer in water-based epoxy coatings and stirred sufficiently , the anti-corrosion coatings were prepared.We studied the morphology and structure of the products by transmission electron microscope (TEM), fourier transform infrared spectrometer (FTIR), and scanning electron microscope (SEM). Through the study the effect of using amount of surfactant, pyrrole, oxidant, and PMMA, the reaction temperature, and the doping agent to the final product, we found the optimal conditions for preparing the core-shell nano conductive composite particles. We also studied the effect of different filers and its using amount on the conductivity and transparency of transparent conductive film and gained the best filer and its using amount.