In this paper, self-sensing cemented soil composites were prepared using multi-walled carbon nanotubes and nano-magnetite as conductive fillers. The effects of mono-doped and co-doped multi-walled carbon nanotubes and nano-magnetite on the early mechanical properties, electrical properties, and self-sensing properties of the cemented soil composites under different forms of loading were investigated. The influence mechanism of multi-walled carbon nanotubes and nano-magnetite on the cemented soil composites was explored by scanning electron microscopy. The results indicate that the incorporation of nano-magnetite has the potential to enhance the early mechanical properties of cemented soil composites. While multi-walled carbon nanotubes enhance the integrity of the conductive network within the cementitious soil, they also mitigate the influence of the polarization effect. The dispersion of multi-walled carbon nanotubes in cemented soil composites can be enhanced through the co-doped multi-walled carbon nanotubes and nano-magnetite, thereby increasing its electrical conductivity. Furthermore, the co-doped multi-walled carbon nanotubes-nano-magnetite not only enhances the stress sensitivity of the cemented soil composites but also sustains a favorable linear relationship between cracks and electrical resistance changes, thereby facilitating more precise and comprehensive crack monitoring.

Landslides are a common occurrence that results in both human and financial losses each year around the world. The conventional methods use a variety of techniques, such as the application of lime, cement, and fly ash, for slope stabilization. Nevertheless, all these materials, to some extent, have their own shortcomings. In this study, multi-walled carbon nanotubes (MWCNTs) application was investigated for slope stabilization. Extensive saturated and unsaturated laboratory testing as well as numerical analyses were conducted in this study for both scenarios of soil with and without MWCNTs. The result from unsaturated testing demonstrates that the air-entry value and saturated volumetric water content of soil with MWCNTs increased compared to soil without MWCNTs, while the unsaturated permeability of soil stabilized with MWCNTs decreased. The result from the SEEP/W analysis during rainfall shows that the pore-water pressure (PWP) in the slope without carbon nanotubes was higher than the PWP in the slope with MWCNTs in the surface area. During rainfall, the factor of safety (FoS) of the slope without MWCNTs declined rapidly and at a high rate according to the Slope/W analysis, whereas the FoS of the slope with MWNCTs only changed slightly and remained safe when compared to the non-stabilized slope.

Poly(butylene succinate) (PBS)-based nanocomposites, reinforced and toughened with ZnO-coated multi-walled carbon nano-tubes (MWCNT-ZnO), demonstrate significantly enhanced properties, making them ideal for potential applied in food packaging applications. This study explores the effects of varying proportions of MWCNT-ZnO on the overall characteristics of these composites. The addition of 0.1 parts per hundred (phr) MWCNT-ZnO optimizes the nanocomposites' mechanical properties, crystallinity, melting temperature, thermal stability, and barrier performance. Specifically, the composite exhibits a 22% increase in tensile strength, a 28.4% rise in yield strength, and a remarkable 95.7% enhancement in the material's elongation at break, compared to the pure PBS matrix. Moreover, these nanocomposites exhibit excellent antibacterial properties, crucial for food preservation and safety. The soil burial test indicates that, except for the addition of 0.1phr which is lower than pure PBS, the biodegradation rate increases with the increasing addition of MWCNT-ZnO. This further suggests that a low nanoparticle filler content can enhance structural compactness, thereby improving the mechanical stability. The study also reveals notable preservation benefits for vegetables. When used for beef packaging, this composite material successfully extends the meat's freshness period, substantially curtails bacterial proliferation, and ensures the beef remains within safe consumption parameters. The combination of enhanced mechanical, thermal, barrier, and antibacterial properties makes PBS/MWCNT-ZnO nanocomposites promising candidates for sustainable and efficient food packaging materials.

Constructing a semi-permanent base on the moon or Mars will require maximal use of materials found in situ and minimization of materials and equipment transported from Earth. This will mean a heavy reliance on regolith (Lunar or Marian soil) and water, supplemented by small quantities of additives fabricated on Earth. Here it is shown that SiO2-based powders, as well as Lunar and Martian regolith simulants, can be fabricated into building materials at near-ambient temperatures using only a few weight-percent of carbon nanotubes as a binder. These composites have compressive strength and toughness up to 100 MPa and 3 MPa respectively, higher than the best terrestrial concretes. They are electrically conductive (>20 S m(-1)) and display an extremely large piezoresistive response (gauge factor >600), allowing these composites to be used as internal sensors to monitor the structural health of extra-terrestrial buildings.

As extraterrestrial construction becomes an increasingly relevant goal in society, it is crucial to identify materials that balance high mechanical performance and ease of sourcing. One such candidate material, suitable for lunar habitat construction, is lunar regolith in combination with urea. This research aims to develop a novel lunar regolith composite for improved material strength. In this study we explore the relationship between the loading of carbon nanotubes within lunar regolith composites and their resulting modification of mechanical properties and porosity. Previous studies have shown the incorporation of carbon nanotubes in various applications such as fly ash composites, increases mechanical properties of interest for the material. The formulation of the composite material consists of lunar regolith, urea, distilled water, phosphoric acid, and carbon nanotube powder. The results of this study will include an assessment of the compressive strength for specimens containing carbon nanotubes at different weight fractions of 0%, 0.25%, 0.50% and 1.00%. Uniaxial compression tests demonstrate a maximum compressive strength of 5.82 MPa. We were able to achieve a 23% increase in compressive strength with carbon nanotube additives over composites containing no carbon nanotubes. However, space habitats require thorough and repeated testing to protect the lives at stake in these extreme environments. This increase in compressive strength allows the development of such materials and will allow for more freedom within the structural possibilities available in space architecture.