Synthesis of ruthenium catalysts functionalized graphene oxide for self-healing applications

Graphene Oxide (GO) was prepared by chemical oxidation of high surface area graphite (G). GO was used to support ruthenium catalysts with the aim to activate self-healing reactions in multifunctional materials able to integrate simultaneously the healing reactions with the very interesting properties of graphene-based materials.Grubbs catalysts 1st (G1) and 2nd generation modified (G2<inf> o-tol</inf>), Hoveyda-Grubbs catalysts 1st (HG1) and 2nd generation (HG2) were covalently bonded to GO preserving the same catalytic activity of the catalysts not bonded to the graphene sheets. GO-G2<inf> o-tol</inf> and GO-G1deactivate during the process of preparation of the self-healing epoxy mixtures at 90°C. Evidence of the self-healing activity of the various catalytic complexes was investigated for both uncured and cured samples. Results show that GO-HG1 and GO-HG2 are not deactivated and hence they are able to trigger self-healing reaction based on the ROMP of 5-ethylidene-2-norbornene (ENB). This behavior is most likely due to the formation of 16 electron Ru-complexes that are more stable than the 14 electron complexes of GO-G1 and GO-G2 catalysts.