Study on properties of simulated lunar soil-based geopolymer reinforced by carbon nanotubes
The quasi-brittle simulated lunar regolith-based geopolymer has drawbacks such as low compressive and flexural strength and susceptibility to microcracking. To overcome these shortcomings, multi-walled carbon nanotubes (MWCNTs), which possess excellent mechanical properties and a bridging effect, were introduced as a nano-reinforcement phase. Under different dispersion temperatures and various MWCNT dosages, the evolution of setting time and mechanical properties of MWCNT-reinforced simulated lunar soil-based geopolymer was systematically analyzed. The experimental results show that at a dispersion temperature of 80 °C and an MWCNT dosage of 0.15 wt%, the enhancement effect on the geopolymer is most significant, with 7-day compressive and flexural strength increasing by 49.8% and 61.7%, respectively, compared with the control group. Meanwhile, the initial and final setting times are significantly shortened. Excessive addition leads to decreased reinforcement efficiency due to nanotube agglomeration. An appropriate amount of well-dispersed MWCNTs can effectively bridge microcracks and promote the geopolymerization reaction, providing key experimental evidence and a technical approach for developing low-alkali-activated, high-performance geopolymer construction materials suitable for the extreme lunar environment.