碳量子点对水泥基材料强度及微观结构的影响

Effects of carbon quantum dots(CQDs)on strength and microstructure of cement-based materials

采用微波法制备碳量子点(CQDs)材料,并将CQDs掺入水泥中制备水泥基复合材料;采用X线衍射仪(XRD)、透射电子显微镜(TEM)、扫描电子显微镜(SEM)测试分析材料的化学组成与结构形貌,通过荧光光谱仪、压力试验机、水泥水化热测定仪测试材料的光学、力学性能以及分析CQDs的掺入对水泥水化热反应和抗压强度的影响。结果表明:微波法制备的CQDs的颗粒粒径为4~6 nm,掺入适量的CQDs能加快水泥水化反应进程,随着CQDs掺入量的增大,水泥基复合材料抗压强度呈现先增大后减小的变化规律,当CQDs与水泥的质量比为2.787×10^(-3)时,水泥基复合材料的抗压强度达到最大(养护28 d,100.98 MPa),比未掺CQDs试样的抗压强度(92.92 MPa)提高了8.67%。

Carbon quantum dots(CQDs)were prepared by microwave method and cement-based composites were prepared by combining CQDs into cement materials.The chemical composition and structural morphology of the prepared samples were analyzed by X-ray diffractometer(XRD),transmission electron microscopy(TEM)and scanning electron microscopy(SEM).The optical,mechanical properties and effects of CQDs on cement hydration heat reaction and compressive strength of the samples were measured by fluorescence spectrometer,compressive strength testing and isothermal calorimetry.Results showed that the particle size of prepared CQDs sample was 46 nm.The addition of CQDs could accelerate hydration reaction process of cement materials.Meanwhile,the compressive strength of cement-based composites increased first and then decreased as the mass fraction of the CQDs increased.When the mass fraction of the CQDs was 2.787×10^(-3),the maximum compressive strength of the cement-based composites after curing 28 d reached 100.98 MPa,and the compressive strength increased by 8.67%compared to cement material without CQDs(92.92 MPa).