Development of novel alkali-activated materials (AAMs) incorporating phase change materials (PCMs) for enhanced thermal regulation in sustainable buildings

This work reports the first alkali-activated material (AAM) that directly incorporates a commercially available, non-microencapsulated paraffinic phase-change material (PCM), yielding a composite potentially suitable for building envelopes, aiming at bridging the gap between effective passive thermal management and both economic and environmental sustainability. AAM matrices were produced with two PCM loadings (∼3.7 and 8.3 wt%) alongside a PCM-free control sample. DSC identified a melting transition near 28 °C with apparent enthalpies of ∼1 and ∼7 J g−1, consistent with effective PCM content and distribution. Preliminary thermal tests, carried out on testing boxes exposed to real summer conditions, allowed the determination of the delay and of the reduction in the propagation of the heat wave passing from the outer to the inner surface of the walls. AAM/PCM samples were able to reduce the inner temperature of the testing box of around 2 °C with respect to the outer temperature, showing a decrement factor of 0.78 and a time lag of around 2 h.