纳米二氧化硅和氧化石墨烯复掺对油井水泥力学性能的影响

Effects of Nano-silica and Graphene Oxide on Mechanical Properties of Oil Well Cement

为了探索氧化石墨烯(GO)和纳米二氧化硅(NS)复掺对水泥力学性能的影响,制备了纳米二氧化硅-氧化石墨烯(NS-GO)复合分散液,并掺入油井水泥制备了NS-GO水泥样品。分别使用X射线衍射仪(XRD)、透射电镜(TEM)和扫描电镜(SEM)、傅里叶红外(FTIR)对样品进行结构表征。结果表明,纳米材料在基材中的分散性对复合材料性能有重要影响,NS与GO的共价结合有利于NS-GO颗粒在水泥碱性环境中的分散;水化28 d后,NS-GO(0.03%GO+1.5%NS)水泥样品的抗折抗压强度分别提高了41.96%和41.71%,远优于单掺纳米材料(0.03%GO或1%NS)的水泥样品;GO和NS具有协同作用,其促进了水泥内部产生柱状和花状水化物,桥接了裂缝,使水泥硬化浆体致密化,最终改善了水泥的力学性能。

To investigate the hybrid effects of graphene oxide(GO) and nano-silica(NS) on mechanical properties of cement, NS-GO hybrid suspension and NS-GO oil well cement sample were prepared. X-ray diffraction(XRD), Fourier transform infrared spectroscopy(FTIR), Scanning electron microscopy(SEM) and Transmission electron microscopy(TEM) were used to characterize the materials structure. The results show that the dispersity of nanomaterials has an important influence on its performance. The flexural and compressive strength of cement with NS-GO(0.03% GO and 1.5% NS) are increased by 41.96% and 41.71% with 28 days of curing, respectively, which is far better than cement with 0.03% GO or 1% NS singly. GO and NS have a hybrid effect on cement, form columnar and flower-like hydration products, bridge cracks and compact hardened cement pastes, all of which are beneficial to reinforcing the mechanical properties of cement.