Effect of graphene oxide on the mechanical properties of cement-based materials and its molecular dynamics simulation
The effect of graphene oxide(GO)on the mechanical properties and microstructure of cement-based materials is studied through mechanical property test and microscopic test methods such as scanning electron mi-croscope(SEM),X-ray diffraction(XRD).Testing results show that compared with the blank sample,the addi-tion of 0.02％GO improves the early compressive and flexural strengths of cement paste specimens obviously.Meanwhile,the addition of GO transforms the aggregation state of Ca(OH)2 crystal,refines the size of CH crystal and makes the structure of cement paste more compact.In order to explore the influence mechanism of GO on ce-ment hydration reaction from the atomic/molecular level,molecular dynamics simulation software Materials Studio(MS)is used to simulate the movement and aggregation of cement hydration products(CH)on the surface of GO.The simulation results show that with the progress of hydration reaction,calcium ions and hydroxyl ions move to-wards the sites of hydrophilic oxygen-containing group,gradually gather around GO molecules and facilitates the formation of CH crystals.With the addition of GO,the Young's modulus of CH microstructure model increased by 26.9％compared to the model without GO,indicating that GO can effectively improve the mechanical properties of CH hydration products.The simulation results are in good agreement with the mechanical and micro perform-ance test results,which can provide a theoretical reference for the design and application of molecular dynamics simulation technology in GO cement-based materials.
万方数据
维普
