氧化石墨烯分散方式及其对水泥砂浆力学性能的影响

Dispersion Method of Graphene Oxide and Its Effect on Mechanical Properties of Cement-based Materials

在饱和氢氧化钙水溶液中,采用木质素磺酸钙(木钙)作为助分散剂协同聚羧酸减水剂(PC)对氧化石墨烯(GO)进行分散,并通过吸光度、原子力显微镜、Zeta电位、SEM和XRD等研究了木钙对GO的分散效果及复掺对水泥砂浆力学性能的影响。结果表明:较PC单独分散GO,额外加入少量木钙能大幅度改善GO的稳定分散能力;当GO掺量为0.03%、木钙与GO的质量比为3∶1时,较于PC单独分散GO试件(即基准试件),助分散下GO掺配的水泥砂浆试件的3 d抗压强度、抗折强度分别提升了40.9%和22.5%,28 d抗压强度、抗折强度分别提升了22.1%和17.2%;相对于基准试件,木钙助分散下掺配GO的砂浆内部结构更密实;木钙与PC具有优异的协同分散GO的功效。

In saturated calcium hydroxide aqueous solution,calcium lignosulfonate(CL)was used as a co-dispersant and polycarboxylic acid water reducer(PC)to disperse graphene oxide(GO),and through absorbance,atomic force microscopy,Zeta Potential,SEM and XRD were used to study the dispersing effect of wood calcium on GO and the effect of compounding on the mechanical properties of cement mortar.The results show that compared with PC dispersing GO alone,adding a small amount of wood calcium can greatly improve the stable dispersing ability of GO.When the GO content is 0.03%with 3∶1 mass ratio of CL to GO,the 3 d compressive and flexural strength of cement mortar specimens mixed with GO co-dispersed by PC and CL is increased by 40.9%and 22.5%,respectively,as comparison with those of only PC-dispersed GO specimens.28 d compressive and flexural strength of the cement mortar specimens is increased by 22.1%and 17.2%.The crystal growth of the hydration products of cement is more uniform and the overall internal structure is more compact at the case of the blending of GO co-dispersed by the addition of CL.CL and PC have an excellent synergy on the dispersion of GO.