Enhancement of self-leveling mortar properties using carbon dots: synthesis, characterization, and mechanisms

Carbon-based nanomaterials, such as carbon nanotubes [CNTs], graphene, and graphene oxide [GO], have been widely investigated for enhancing the properties of cement-based materials. However, their high cost, dispersion challenges, and compatibility issues with cement matrices limit their practical applications. In contrast, carbon dots [CDs], a novel class of carbon-based nanomaterials, offer a promising alternative due to their low cost, non-toxicity, excellent water solubility, and facile synthesis. This study investigates the effects of CDs on the performance of self-leveling mortar [SLM], with a focus on fluidity, mechanical properties: compressive and flexural strengths, shrinkage, and abrasion resistance. CDs were synthesized via a one-step hydrothermal method and incorporated into SLM at varying dosages. The experimental results show that the addition of CDs significantly improves the fluidity and mechanical properties of SLM, with the optimal dosage [3‱] yielding the highest compressive and flexural strengths. Furthermore, CDs effectively reduce the shrinkage and enhance the abrasion resistance of SLM. Microstructural analysis revealed that CDs promote the formation of calcium silicate hydrate C-S-H gel, leading to a denser and more stable matrix, which contributes to improved mechanical performance and durability. Overall, this study highlights that CDs are a cost-effective and sustainable additive for enhancing the performance of cement-based materials, offering a viable alternative to more expensive nanomaterials.