纳米碳管/水泥基复合材料的阻尼及力学性能

以水泥为基体、多壁纳米碳管为增强组分，采用表面活性剂超声分散法，浇注成型制备了5组多壁纳米碳管/水泥阻尼自增强复合材料(FRCs)。在一弹性自由支撑体系中采用锤击自由衰减法初步探讨了FRCs的阻尼性能，随后采用三点弯曲法测试了FRCs的抗弯折强度，并对其阻尼及力学增强的微观机理进行了探讨。结果表明：相比于参比试件，掺有纳米碳管的FRCs试件的阻尼比及抗弯折强度均得到一定的提高，增幅分别达24.5%、35.98%。FRCs表现出较好的耗能及增韧能力主要归因于硅灰的微填充与界面效应和多壁纳米碳管的微纳米填充桥联、相互界面层间内摩擦及弹塑性波动效应。

Damping capacity and flexural strength of multi-walled carbon nanotube/cement composites

Five fiber reinforced cement composites (FRCs) with varying multi-walled carbon nanotube (MWNTs) loadings were cast mixed with the aid of surfactants and ultrasonic dispersion. Their damping capacities and flexural strengths were investigated by the free vibration testing method in an elastic system, and the three-point bending technique, respectively, and the microstructure morphologies of the MWNT distributions within the cement matrix were observed and analyzed. The results show that there are positive effects on the resonant damping ratio (ζ) and flexural strength (σ-t) of FRCs associated with addition of some MWNTs, with enhancement amplitudes of 24.5% and 35.98%, respectively, relative to the reference. The in-filling and bridging effect on the micro &; nano scale of fumed silica and nanotubes, and the elastic plastic fluctuation effect, the inner surface frictions between the MWNTs and the interfaces between the MWNTs and matrix greatly increase, which contribute to the observed good damping capacities and mechanical reinforcement afforded by the FRCs.