M. Galimberti, V. Barbera, A. Bernardi, D. Locatelli, G. Prioglio
Politecnico di Milano,
Italy
Keywords: graphene, functionalization
Summary:
Facile, sustainable and versatile functionalization of graphene layers was performed [1-4]. Functional groups were essentially at the layer edges and the structure of the graphitic substrate remained substantially unaltered. Functionalization was done with pyrrole compounds (PyC) prepared through the Paal-Knorr reaction of a primary amine with 2,5-hexanedione. A good number of primary amines were used and a large variety of functional groups were added to the graphene layers: hydroxy, silanes, aldehydes, carboxylic acid. The functionalization reactions were carried out by simply mixing the reagents and heating, e.g at 150°C for 3 hours. The reactions had good yield, up to 96%, and atom efficiency up to 80% and scale up was done to kg level. A domino process has been hypothesized as the mechanism of the functionalization reaction, made by successive Paal Knorr reaction, carbocatalyzed oxidation and cycloaddition. A good number of applications have been successfully explored: inks and varnishes, advanced lightweight nanocomposites materials, e.g.: rubbers for low dissipation of energy, flame retardant polyurethanes, biobased carbon papers and aerogels. The intellectual property of this functionalization technology is characterized by many families of Patents. References [1] M. Galimberti, V. Barbera. R. Sebastiano, A. Valerio, G. Leonardi. WO2016050887A1 [2] M. Galimberti, V. Barbera, S. Guerra, L. Conzatti, C. Castiglioni, L. Brambilla, A. Serafini, RSC Adv., 2015, 5, 81142-81152 [3] M. Galimberti, V. Barbera. WO2018087685A1 [4] V. Barbera, A. Bernardi, A. Palazzolo, A. Rosengart, L. Brambilla, M. Galimberti, Pure Appl. Chem., 2018, 90(2), 253–270