Morphology-controllable paraffin@lead tungstate microcapsules for gamma radiation shielding and thermal energy storage

Abstract

A novel morphology-controllable microencapsulated paraffin (Pn) with lead tungstate (PbWO4) shell was successfully fabricated by in‐situ precipitation and self-assembly methods. The morphology of microcapsules can be transformed from spindle to spherical by adjusting the content of trisodium citrate dihydrate (TSCD) to control growth of PbWO4 shell. The spindle microcapsules demonstrated higher encapsulation ratio and lower supercooling degree than the spherical. The Pn@PWO microcapsules not only showed high latent heat-storage capacity over 100 J/g and excellent solid-liquid phase-transition reversibility and cycle stability for thermal regulation, but also exhibited high thermal conductivity over 0.596 W·m−1·K−1, good thermal storage ability, positive leakage-prevention performance. Meanwhile, due to the existence of PbWO4 shell, the highest mass attenuation coefficients of microcapsules at 86.5 keV and 105.3 keV reach 1.98 and 2.08 respectively, showing excellent gamma shielding performance. The novel kind of multifunctional Pn@PWO microcapsules can demonstrate potential application prospects in fields such as protective textiles and nuclear engineering buildings which require simultaneous gamma radiation shielding and thermal regulation.