Superior performance foamed concrete fabricated with amphiphilic and hydrophilic particles stabilized ultra-stable foam

Materials possessing sufficient strength, exceptional thermal insulation, and energy-efficient characteristics are in short supply within the construction industry. Foamed concrete, known for its cost-effectiveness, ultralight composition, and prominent thermal insulation characteristics, has displayed significant potential in applications geared towards enhancing energy efficiency. Nevertheless, its widespread adoption is hindered because, at present, the strength and thermal insulation properties of foamed concrete fail to meet engineering requirements due to inadequate foam stability. In response to this challenge, an ultra-stable foam with a multi-walled core-shell structure is successfully synthesized by modifying the gas-liquid interface through coupling the synergistic effects of surfactant, Janus-ZrO2 nanoparticles, and hydrophilic homogeneous SiO2. Utilizing the innovative approach, we incorporate the ultra-stable foam, containing 5 wt% Janus-ZrO2 nanoparticles, in the fabrication of foamed concrete with a resultant density of 500 kg·m-3. Notably, this foamed concrete exhibits remarkable mechanical properties (compressive strength of 5.1 MPa) and outstanding thermal insulation performance (thermal conductivity of 0.091 W/(m·K)). These enhancements can be attributed to the refining of the pore structure and an increased proportion of closed pores within the foamed concrete, both facilitated by the utilization of the ultra-stable foam. The introduction of this unique ultra-stable foam is poised to expand the applications of foamed concrete in the construction sector.