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

- Grubbs and Hoveyda-Grubbs catalysts were covalently bonded to GO.
- The developed GO based catalysts activate ROMP reactions.
- Self-healing activity in epoxy formulations has been proven.

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 (G2o-tol), 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-G2o-tol 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.

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