PSI - Issue 28

Angeliki-Eirini Dimou et al. / Procedia Structural Integrity 28 (2020) 1679–1685 Author name / Structural Integrity Procedia 00 (2019) 000–000

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4. Conclusions In the present work, aqueous rGO dispersions were studied with Electrical Impedance Spectroscopy. The aim of the study was to find the appropriate dispersion to be incorporated in a cementitious matrix as a future step. Through the application of EIS, the concentration of rGO and the optimal amount of sonication energy were determined. The results showed that at low rGO concentrations the electrical impedance decreases as sonication energy increases, indicating a better and more uniform dispersion, leading to the formation of conductive networks. In higher rGO concentrations, an increase in sonication energy up to intermediate energy values leads to an increase of the electrical impedance, but a further increase of the applied energy leads to lower values of the impedance. The results indicated that the aqueous solution with rGO concentration level at 0.15 wt% of the binder and at sonication energy of about 60 kJ is appropriate to be used to produce the cementitious composites. Acknowledgements This research has been co‐financed by the European Regional Development Fund of the European Union and Greek national funds through the Operational Program Competitiveness, Entrepreneurship and Innovation, under the call RESEARCH – CREATE – INNOVATE (project code: T1EDK-03069, MIS 5031866, project name: Self-healing and self-sensing nano-composite conservation mortars – acronym: AKEISTHAI). The authors would also like to thank Professor Dimitrios GOURNIS (University of Ioannina, Department of Materials Science & Engineering) for providing the nanomaterials used in the present work as well as Assistant Professor Zoi METAXA for her valuable comments on the mixing technique under the framework of the AKEISTHAI research project. 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