Mechanical and temperature control properties of energy storage mortar based on bio-coating/phase change microcapsules

In order to study the effect of bio-coating/phase change microcapsules on the mechanical and temperature control properties of cement mortar, phase change microcapsules (PD-PCM) coated with polydopamine on the surface were introduced into cement mortar to make energy storage mortar. The microstructure, mechanical properties, thermal properties and temperature control properties of energy storage mortars with different PD-PCM dosages (5%-20%) were investigated under the low-temperature environment in winter. The results show that: the porosity of energy storage mortar increases with the increase of PD-PCM dosage, and the porosity of 20% dosage increases by 23.2%; the addition of PD-PCM effectively slows down the significant decrease of compressive strength of traditional phase change energy storage mortar, and its 5% and 10% dosage increase by 3.6% and 3.8% respectively compared with the baseline mortar, and the 20% dosage decreases by 16.8%; the addition of PD-PCM improves the thermal performance of the mortar, and the thermal performance of the mortar is improved by 20% dosage, and the thermal performance of the mortar is reduced by 20%. The addition of PD-PCM improves the thermal performance of mortar, its thermal conductivity decreases with the increase of PD-PCM dosage, and the thermal resistance increases with the increase of PD-PCM dosage, the thermal conductivity decreases by 25.8% with 20% dosage, and the thermal resistance improves by 38.9%; through the experiment of adiabatic box, it can be seen that when the dosage of PD-PCM is 20%, the valley temperature and time lag of its box increase by 1.1℃ and 10 min, compared with that of the standard cement mortar, respectively. The phase change energy storage mortar has good thermal performance and energy storage and temperature regulation capability while meeting the requirements of mechanical properties, which has a broad application prospect in the field of building temperature regulation.