Physisorption of perylene dyes on graphite​

This thesis work was carried out at CNR of Bologna. CNR- ISOF (Institute of Organic Synthesis and Photoreactivity) in the group of Dr. Vincenzo Palermo. The aim of this thesis was to perform a comparative and quantitative study on the interaction of three different PDI (perylene diimide) dyes with graphene (G) sheets in solution, using a phenomena called “dye’s capturing”. The only difference between the PDI dyes tested was the terminal atom in the side groups. In particular, we used a perylene core with side ethyl-phenyl group exposing in the para position a hydrogen (PDI-H), fluorine (PDI-F), or chlorine atom (PDI-Cl). Although the relative simplicity of the process and the measurement itself, the preparation of a reliable experimental setup is not trivial and several issues had to be taken into account. The main challenges to be overcame were related to the effective stability and reliability of the chemical systems, such as dyes, solution and graphite during the entire exposure time. For this reasons the work addressed the following issues: 1)Studying the interaction of small organic molecules and graphite flakes, using commercial products. 2)Finding the best conditions for the dye capturing process (concentration, stabilization of the solution, solvent etc.).3)Understanding of the “dye’s capturing” phenomena by UV-VIS and fluorescence techniques. 4)Stabilizing a relationship between the chemical structure of PDI-X (with side chains symmetrically terminated with a different atom) and the interaction with graphite, taking into account adsorption speed, packing, etc. 5)After testing the samples, the reported results were used to: 1) Determinate the best suitable molecule for the dye capturing process, and optimize a hypothetical industrial process by calculating the surface area for each molecule. 6)Morphology and structural characterizations with different technique like: AFM, SEM, EDX, XRD, fluorescence microscopy, TGA/DSC, IR.