Modeling the thermal behavior of multifunctional syntactic foams containing phase change materials for heat management applications

Syntactic foams are lightweight porous composites obtained by the addition of hollow glass microspheres (HGMs) to a polymer matrix. This work experimentally and numerically investigates the thermal behavior of epoxy-based syntactic foams with enhanced multifunctionality produced by incorporating microencapsulated phase change materials (PCMs) as functional fillers, providing thermal energy storage and temperature stabilization due to its large latent heat of melting. Foams are fabricated using varying ratios of HGMs (0–40 vol%) and PCM (0–40 vol%) to achieve tuned densities and thermal properties with a total filler content of up to 40 vol%. A one-dimensional numerical heat transfer model based on the enthalpy method is presented to simulate the thermal behavior of these materials. The model accurately incorporates the specific heat and thermal conductivity of the foam components, as well as the latent heat absorption during PCM melting (up to 68 J/g). The model is experimentally validated by demonstrating good agreement with the measurements of transient temperature profiles during heating tests on the foam samples. The validated tool is then leveraged to model the thermal response of the foams under a sinusoidally varying heat source, similar to the possible real applicative scenarios. These results can help optimize foam compositions balancing energy storage density, heat transfer properties, and structural support for lightweight energy storage systems. Potential applications include high-efficiency thermal management in battery packs, electronic cooling, solar energy storage, and sustainable temperature-controlled buildings. Highlights: Foams with 0–40 vol% PCM and 0–40 vol% HGM show up to 68 J/g latent heat. 1D numerical model accurately captures thermal conductivity and PCM phase change. Validated model simulates thermal response under sinusoidal heat, optimizing foam composition. Foams act as thermal reservoirs, maintaining up to 5°C lower surface temperatures than epoxy.