氧化石墨烯对碱矿渣胶结材浆体流变性能的影响

Effect of Graphene Oxide on the Rheological Properties of Alkali-Activated Slag Paste

采用改进Hummers法制备了氧化石墨烯(GO),使用旋转黏度计测试了掺GO新拌碱矿渣胶结材浆体(AASP)的剪切应力,并基于Herschel-Bulkley(H-B)模型计算了浆体的流变参数,分析了GO对碱矿渣胶结材浆体流变性能的影响.结果表明:GO降低了碱矿渣胶结材浆体的触变性能,提高了浆体的稳定性;GO掺量(质量分数,下同)由0.01%增至0.05%时,碱矿渣胶结材浆体的屈服应力和稠度系数增大、流动度降低、滞回环面积和流变性指数减小、浆体的触变性能降低;GO与矿渣粉颗粒通过化学键合作用生成絮凝结构,且随着GO掺量增加,絮凝结构的数量增多,浆体的流变性能发生变化;掺1.5%萘系减水剂(FDN)可将掺0.03%GO的碱矿渣胶结材浆体流动度由180mm提高到203mm,即掺加FDN可提高含GO碱矿渣胶结材浆体的流动性.

The graphene oxide(GO)was prepared by modified Hummers method.The shear stress of the fresh alkali-activated slag paste(AASP)with GO was measured by rotary viscometer,and the rheological parameters of the obtained paste was calculated based on Herschel-Bulkley(H-B)model.Results show that GO reduce the thixotropic properties and increased the stability of the fresh AASP.With GO content(by mass,the same below)increased from 0.01%to 0.05%,the yield stress and consistency coefficient of fresh AASP increase,while the fluidity reduce.At the same time,hysteresis loop area and rheological index decrease with the increase of GO content,and GO decrease the thixotropic properties of the paste.A mechanism for the effect of GO on the rheological properties is proposed,which specifically explained as GO and slag particles are chemically bonded to form flocculation structures.Furthermore,the flocculation structures increase with the increase of GO content with the result that the rheological properties of the paste changed.The fluidity of AASP containing 0.03%GO is increased from 180 mm to 203 mm by incorporating 1.5%FDN,which indicated that the addition of FDN can increase the fluidity of GO-AASP.