Synthesis of azobenzene-functionalized polycarbazole-based conductive polymer films and solar thermal storage applications

Efficient utilization of the sun as a renewable and clean energy source is one of the greatest goals and challenges of this century due to the increasing demand for energy and environmental impact of the fossil fuels. Solar energy conversion in form of molecular photoswitches holds great potential to store energy from sunlight in form of chemical energy. Although polymer-based solar thermal fuels have a high potential to be used in solar energy storage applications, in earlier academic literatures, it was found that the solar energy storage capacity of the polymeric STF is lower than that of the respective monomer. In this thesis, for the first time, electro/photosensitive monomers were synthesized by combining electroactive carbazole molecules and photoactive azobenzene groups. The isomerization kinetics of monomers, of which structural characterizations are characterized by NMR and FTIR spectra, were examined and solar thermal storage capacities were calculated. Conductive polymer films were obtained by electrochemical polymerization of electro/photoactive monomers in a three-electrode system. The electrochemical characterization and thermal stability of the polycarbazole-based photoactive conductive films were examined and their solar thermal storage capacities were calculated. When the solar energy storage capacities of monomers and polymers were compared, it was determined for the first time that the solar energy storage capacities of polymeric STFs were higher than monomer structures. This study showed that polycarbazoles containing azobenzene pendant groups can be an effective solar thermal storage platform due to their easy functionality, high light absorption and rigid conjugated chain structures decorated with tightly packed photochromic units.