Symbiotic impact of carbon quantum dots on microstructural development and mechanical behaviour of cement mortars

Carbon Quantum Dots (CQDs) are a new environmentally pleasant material of the carbon family that has gained great interest in construction engineering due to their unique and valuable properties, such as high stability, minimizing toxic activity, and good water solubility. Therefore, this study aims to synthesize the CQDs using glucose as a precursor and apply it as nano-reinforcements in cement mortar. X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and transmission electron microscopy (TEM) technologies were used to characterize the generated CQDs. The mechanical properties of the created CQDs-cement mortar were investigated by assessing the compressive and flexural strengths as well as the workability of the mortar samples. Experimentally, four different percentages of the developed CQDs— ranging from 0.005% to 0.030%—were added to the cement mortar. The acquired results showed that, at the age of 56 days utilizing 0.025% CQDs, the compressive and flexural strengths of the CQDs-cement mortar had grown by 72% and 59%, respectively. The workability study's findings revealed no evidence of a significant impact of CQDs on the mortar's flow characteristics. In conclusion, the findings of this study may suggest that CQDs can be used to enhance the mechanical properties of materials based on cement.