Effect of Rice Husk Ash on Dispersion of Graphene Oxide in Alkaline Cementitious Environment.

Two-dimensional nano graphene oxide (GO) has attracted the attention of researchers due to its excellent high aspect ratio and intrinsic strength. However, its effectiveness in improving cement composite's performance is significantly dependent on the uniform dispersion of GO in the host matrix. In recent years, the use of pozzolans, such as fly ash, silica fume, and metakaolin, to enhance the dispersion of GO in cement medium has become a focus of research. This study considered the effect of rice husk ash (RHA) on the GO dispersion quality in simulated cement pore solution (SCPS). The findings obtained were validated by the compressive and flexural strengths of cement paste samples. According to ultraviolet–visible (UV-vis) spectroscopy, zeta potential analysis, and other measurements, this research demonstrated that the addition of RHA to SCPS minimizes the size of GO agglomerations and considerably enhances dispersion. The compressive and flexural strength results of cement paste samples incorporating RHA-GO after 56 days of curing improved by 46.7% and 38.7%, respectively, compared with those of the reference samples. The results of this study could pave the way for application of binary GO-pozzolans containing cementitious nanocomposites. [ABSTRACT FROM AUTHOR]