Resumen de Estudio de mejora de las propiedades de polímeros conductores electrogenerados. Verificación de parámetros de aplicación tecnológica
Since their discovery, the spectacular properties of polymers called "conducting" have given rise to an important field of study in order to obtain knowledge about them and their commercial application in many fields such as those reviewed in first chapter of this thesis.
To achieve the greatest potential of conducting polymers (CP) an improvement in making the polymerization processes is needed. Ways of obtaining conducting polymer based materials with electric properties in accordance with the corresponding applications are required.
In the second chapter, the experimental methodology applied to the development of the studies that constitute the later chapters has been advanced. This chapter has also included all the analytical techniques used.
The study of the optimization of electrochemical polymerization conditions of two conducting polymers such as poly(3,4-ethylenedioxythiophene) (PEDOT), poly(N-methylpyrrole) (PNMPy) and three-layered systems formed of alternating films from the two previous CPs has been presented in the third chapter. This improvement has been divided into two phases: - The reduction of the monomer concentration in the solution and simultaneous application of dynamic flow conditions therein during the electrochemical generation.
- The reduction of the concentration of supporting electrolyte, keeping the monomer concentration at the previous reduced value and stirring the solution, as in the previous case. This second decrease has only been applied to PEDOT.
The purpose of these studies has been to decrease the pollutant load of depleted solutions, reducing the environmental impact in CP films manufacturing, which has also maintained and even increased some of the properties of their electrical response. The effectiveness of the method by making an application in a supercapacitor has also been demonstrated.
In the fourth chapter, studies about electrolytic polymerization and characterization of the properties of the composite materials obtained with a PNMPy base and two types of incorporations have been developed as: - Cu nanoparticles obtained by the reduction reaction of an aqueous solution of copper chloride (II).
- Nanoparticles of molybdenum oxide (VI) suspended in an acetonitrile-water mixture.
With the making of these composite materials, modulating the electroactive properties of the PNMPy has been pursued.
The fifth chapter has focused to the study of obtaining PEDOT and PNMPy alternating layers to form three-layered films whose intermediate layer incorporates a dielectric material such as montmorillonite (MMT) clay. The influence of this type of clay has been related to the properties regarding the thickness of the PEDOT inner and outer layers. These materials have also been characterized for their application as supercapacitors.
Finally, PEDOT films generated in acetonitrile and deionized water solutions have been subjected to a simple thermal treatment whose results have been studied in sixth chapter. This treatment has caused an increase in the material conductivity that has been associated with a modification of its physical structure, which depends on the solvent used in the anodic polymerization. The nature of the structural changes promoted by the heat treatment has also been analysed.
