Ceramics-Silikáty 68, (2) 205 - 215 (2024)

The agglomeration of graphene oxide (GO) in cement mortar poses a serious obstacle to the development of the mechanical properties of cement composites and limits its practical application. To address this issue, quaternised poly (4-vinylpyridine) grafted GO (QP4VP@GO) were prepared through chemical grafting of quaternised P4VP onto the surface of GO using atomic transfer radical polymerisation (ATRP) and the QP4VP@GO doped cement-based composites (QP4VP@GO/C) were subsequently prepared. X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FT-IR) were utilised to investigate the structural characteristics of the modified GO. It was observed that the dispersion of quaternised-P4VP grafted GO in the calcium hydroxide (Ca(OH)₂) solution exhibited better performance compared to GO. Additionally, when 0.03wt.% of the QP4VP@GO was incorporated into the cement composite, the maximum flexural strength at 28 d of the cement-based composites reached 8.0 MPa, which shows an obvious improvement compared to ordinary Portland cement and GO cement-based composites. Similarly, with the addition of 0.05wt.% of QP4VP@GO, the maximum compressive strength at 28 d of the cement-based composites was enhanced to 72.4 MPa. Furthermore, the SEM characterisation results demonstrated that the inclusion of QP4VP@GO facilitated the enhancement of cement hydration, impeded the crack expansion, and improved the mechanical properties of the cement composites.