一种改善高掺量碳纳米管/水泥砂浆性能的方法

A method to improve the microstructure and mechanical properties of carbon nanotube/cement matrix

碳纳米管(CNTs)在水泥砂浆中分散困难,并显著增加用水量,CNTs掺量较高时,水泥砂浆的各项性能显著降低。基于机械力-化学效应,利用粉煤灰的形态效应和二次水化特征,采用混磨工艺(MD)制成了粉煤灰-CNTs复合粉末,并将其制成CNTs-水泥砂浆(MCNT)。力学性能测试结果表明,MCNT的力学性能随着CNTs掺量的增加而增加。透射电子显微镜(TEM)和红外分析(FT-IR)测试结果表明,MD工艺使得CNTs表面接枝了粉煤灰活性组分,改善了CNTs-水泥的界面性能。场发射扫描电镜(SEM)测试结果表明,MD工艺实现了高掺量CNTs在水泥砂浆中的均匀分散。

Carbon nanotubes (CNTs)have long been recognized as the stiffest and strongest man-made material known to date.CNTs reinforced cement matrix,having high mechanical properties,an excellent piezoresistivity and electromagnetic shielding property,may be used to develope an intrinsically self-sensing structural materi-al.However,CNTs are usually very difficult to disperse in an aqueous solution due to their low mass and strong van der Waal's attraction to each other.A new method was used to disperse CNTs on basis of mechano-chemis-try effect in this paper by grinding carboxylated CNTs and fly ash.The mineralogy and microstructure were an-alyzed by using scanning electron microscope(SEM)and Fourier transform infrared spectroscopy (FT-IR).It was shown that CNTs ware wrapped by cementitious,and well dispersed throughout cement matrix.Further-more,the strength of CNTs-cement composites was improved after modified by using this method.