Effect of Fungal Mycellium/Eicosane Composites on Thermal Energy Storage and Release in Gypsum Plaster

The deposition of organic phase-change materials (PCMs) on the supporting fibers was shown as a simple and effective way to prepare stable composites with thermoregulating properties, which are feasible as functional additives to dry building mixes. However, the preparation of the composite fibers with optimal morphology to improve their content and thermoregulating performance in the target material still remains challenging. Herein, we report on the stable composite fibers prepared by the deposition of organic PCM eicosane on the biopolymeric fibers of fungal mycelium. The prepared composite had a fibrous morphology with the longitudinal diameter of 1–1.5 μm and the latent heat capacity of 63.2 J/g. The composite was mixed with the dry powder of gypsum plaster with the mass content of 15% and 30%. The electron microscopy revealed a homogeneous distribution of the fibers within the hardened plaster layer. The differential scanning calorimetry confirmed that the addition of the composite to the plaster enhances its thermal performance and brings latent heat storage and release capability with latent heat capacity of 8.2 J/g and 18.2 J/g depending on the composite content. The measurement of the temperature in the volume of the hardened plaster demonstrated that the addition of the thermoregulating fibers effectively reduce the heating rate in the range of 37–39°C and the cooling rate in the range of 38–34°C, corresponding to melting and crystallization of eicosane in the composite structure.