Integrating AgNPs-decorated phase change microcapsules into UV-cured PUA with enhanced thermal conductivity for solar thermal energy conversion and storage

Developing smart flexible film based on high thermal conductivity phase change microcapsules (MPCM) is essential for personal thermal management, which could provide sufficient warmth for individuals outdoor through the phase change behavior. Herein, we report the synthesis of n-octadecane MPCM with a composite shell of silver nanoparticles (AgNPs) and melamine-formaldehyde (MF) resin, followed by surface modification to create Ag@MPCM with enhanced thermal conductivity. These were combined with PUA resin to fabricate composite films exhibiting phase change properties. The 1Ag@MPCM (the ratio of AgNO₃ to MPCM is 1:1 during modification) demonstrated an ideal thermal storage capacity (up to 108.20 J/g). The thermal conductivity of it exhibited 0.643 W m⁻¹ K⁻¹, representing a 242 % improvement compared MPCM. AgNPs, serving as thermal conductive fillers, exhibited localized surface plasmon resonance (LSPR). It enhances the radiative absorption capability and thermal conductivity of MPCM, thereby accelerating the phase change process. Compared to pure PUA, the thermal conductivity of 30Ag@MPCM-PUA (0.186 W m⁻¹ K⁻¹) was increased by 29 %. After 300 s of simulated solar irradiation, the temperature of 30Ag@MPCM-PUA is 48.1 °C higher than that of PUA. Furthermore, the 30Ag@MPCM-PUA exhibited good thermal conductivity and excellent photothermal conversion properties. Overall, 30Ag@MPCM-PUA holds significant potential for personal thermal management field.