Thermal energy storage foam concrete incorporating n-Octadecane/CuO microcapsules synthesised via Pickering emulsion strategy

This study developed a novel encapsulation methodology for the synthesis of phase change material microcapsules based on the Pickering emulsion strategy. Cu 2 O nanoparticles were selected as emulsifier in this study, effectively stabilised n -Octadecane (C 18 ) Pickering emulsions and acted as precursors for shell formation, leading to the successful formation of C 18 /Cu 2 O colloidosomes. Upon self-oxidation, Cu 2 O transformed to CuO, enabling crosslinking between neighbouring particles on the emulsion and forming robust microcapsule CuO shells. The resulting C 18 /CuO microcapsules retained a high latent heat capacity after encapsulation, indicating effective thermal storage performance and high encapsulation efficiency. The C 18 /CuO also demonstrated thermal reliability after repeated thermal cycling and improved charging/discharging rate as compared to pure C 18 , making it highly suitable for improving thermal performance in energy-efficient construction materials. Thermal energy storage foam concrete containing 20–50 % C 18 /CuO microcapsules was prepared. Infrared thermal imaging indicated that the C 18 /CuO-derived composites exhibited slower temperature rise and faster cooling response. A thermal conductivity of 0.6112 W/m K was achieved at 50 % C 18 /CuO inclusion, demonstrating the potential of the C 18 /CuO-modified foam concrete for energy efficiency applications. • A novel Pickering emulsion-based encapsulation for n-Octadecane/CuO synthesis. • Cu 2 O nanoparticles stabilised Pickering emulsion forming core-shell colloidosomes. • Cross-link CuO subunits formed robust shell walls. • High latent heat capacity and thermal cycling reliability of the microcapsules. • n-Octadecane/CuO modified foam concrete showed enhanced thermal performance.