Phase-Change Copmosite Fibers as a Thermoregulating Additive to Dry Building Mixes for Bimodal Solar/Electromagnetic Energy Storage

The work is devoted to the study of phase-change composite fibers as a thermoregulating additive to dry building mixes with the possibility to accumulate thermal energy under the sunlight heating or exposure to high-frequency alternating magnetic field.The composite fibers were prepared by adsorption of organic phase-change material eicosane on the surface of cellulose microfibers modified with magnetite nanoparticles. The resulted composites demonstrated the latent heat storage capacity of 129-148 J/g depending on the eicosane content. The addition of 10-15 wt% of the composite fibers to the dry building mix brought the latent heat storage and release properties to the hardened samples in the temperature range from 27°C to 43°C, which corresponds to melting and crystallization of eicosane in the composites structure. The addition of phase-change composites affected on heatingof the hardened plaster under the simulated sunlight and its further cooling under ambient conditions. The samples demonstrated more intensive heating and reduced cooling rate upon reaching 35°C as compared to control samples. Additionally, the hardened plasters containing the phase-change composites demonstrated the capability to accumulate thermal energy under high-frequency alternating magnetic field exposure attended with its prolonged release.