We use surface-modified graphite nanoplatelets (GNPs) to engineer cement materials at the nanoscale to effectively tailor their macroscale crucial mechanical properties suitable for harsh conditions. Concerning long-term public health and global warming, nanoengineering of cement as a primary barrier for providing zonal isolation by sealing in areas requiring very low risk of serious accidents becomes imperative. Cement inherently possesses microstructural defects, such as, pores/voids and microcracks, which can jeopardize its sealing functionality under large confining in-situ stresses. Here, we develop a chemical methodology for the surface treatment of GNPs, enabling us to enhance chemical and physio-mechanical properties of the produced cement nanocomposite. This surface modification not only changes the hydrophobicity of nanoparticles to hydrophilicity and provides a uniform dispersion of nanoplatelets in aqueous media but also results in the formation of a strong bonding at the GNP/matrix interfaces. The innovative nanoengineered cement composite shows extraordinarily enhancement in the compressive strength, flexural strength, Young's modulus, and the ductility up to $317\%$, $209\%$, $255\%$ and $131\%$, respectively, as compared to the neat cement without using any sort of vibrations during curing. We utilize 3D X-ray computed tomography (CT) in conjunction with the optical microscopy (OM) to visualize the quality of nanoparticles' dispersion. Moreover, scanning electron microscopy (SEM) is used to discern the formation of strong bonding at the GNP/cement matrix interfaces, pore/void refinement and crack bridging.

我们使用表面改性的石墨纳米片（GNP）在纳米级上对水泥材料进行工程设计，以有效地调整其适用于恶劣条件的宏观关键机械性能。关于长期的公共卫生和全球变暖，水泥纳米工程作为通过密封在需要严重事故风险极低的区域提供区域隔离的主要障碍变得势在必行。水泥固有地具有微观结构缺陷，例如孔隙/空隙和微裂纹，这些缺陷可能会在较大的现场约束应力下危害其密封功能。在这里，我们开发了一种化学方法来对GNP进行表面处理，使我们能够增强所生产的水泥纳米复合材料的化学和物理机械性能。这种表面改性不仅将纳米颗粒的疏水性改变为亲水性，并在水性介质中提供纳米片的均匀分散，而且还导致在GNP /基质界面形成牢固的键合。创新的纳米工程水泥复合材料的抗压强度，抗弯强度，杨氏模量和延展性均显着提高$317％$， $209％$， $255％$ 和 $131％$与纯水泥相比，固化过程中没有使用任何形式的振动。我们将3D X射线计算机断层扫描（CT）与光学显微镜（OM）结合使用，以可视化纳米颗粒的分散质量。此外，使用扫描电子显微镜（SEM）可以识别在GNP /水泥基体界面处形成的牢固结合，孔隙/孔隙细化和裂纹桥接。