氧化石墨烯纳米片层对水泥基复合材料的增韧效果及作用机制

通过氧化和超声波分散制备了氧化石墨烯（GO）纳米片层分散体系，研究了GO纳米片层对水泥基复合材料的增韧效果及作用机制。用EDS、FTIR、XRD、SEM和AFM对GO纳米片层的结构进行了表征。研究结果表明：所得GO含氧量为32.3wt%，GO纳米片层的厚度为6 nm左右，在GO片层表面含有羟基、羧基和磺酸基等活性基团。水泥基复合材料的SEM形貌及力学性能测定结果表明：当GO掺量为0.03wt%时，GO能够使水泥水化产物形成花朵状晶体，并使水泥基复合材料的拉伸强度、抗折强度和压缩强度比对照样品分别提高了65.5%、60.7%和38.9%。提出了GO纳米片层对水泥水化产物的模板调控机制，揭示了花状晶体的形成过程。

Toughening effect and mechanism of graphene oxide nanosheets on cement matrix composites

A dispersion system of graphene oxides (GO) nanosheets was prepared by oxidization and ultrasonic treatment. The toughening effect and mechanism of GO nanosheets on cement matrix composites were investigated. GO nanosheets structure was characterized by EDS, FTIR, XRD, SEM and AFM. The results indicate that the oxygen content of GO is 32.3wt%, the thickness of GO nanosheets is about 6 nm and there are many hydroxyl, carboxyl and sulfonic groups on the GO surface. The results of SEM images and mechanical strength indicate that GO can prompt the formation of flower-like hydration crystals and increase the tensile, flexural and compressive strength of the corresponding mortar 65.5%, 60.7%, 38.9% compared with the control samples, respectively, when GO dosage is 0.03wt%. The templating regulation mechanism of GO nanosheets on cement hydration crystals is proposed and the formation of the flower-like hydration crystals is revealed.