Preparation of photothermal conversion and energy storage microcapsules based on Pickering emulsions with poly (p-phenylenediamine) as stabilizer and photothermal materials

Passive energy recycling for thermal management is one of the best energy-saving paths. However, phase change energy storage driven by temperature fluctuation is difficult to realize in some application scenarios such as winter or alpine regions. Here, novel photothermal conversion and energy storage composite was designed and fabricated to solve the problem. Firstly, nanoscale poly (p-phenylenediamine) (PPPD) as stabilizer and photothermal conversion material was synthesized and used in the encapsulation of lauryl myristate as phase change material (PCM) with phase change temperature of 34.6 °C based on Pickering emulsion, following photoinduced energy storage microcapsules were successfully prepared using melamine formaldehyde resin as shell. The obtained microencapsulated phase change materials (MPCMs) can absorb and release heat energy within a temperature range of 25–45 °C with a latent heat of 185.7 J/g. Owing to the excellent photothermal conversion efficiency of the MPCMs (82.4 %), their temperature-regulating function can be triggered in those low temperature environments by photothermal conversion. The microcapsules were then treated on fabric by printing and showed good thermal management effect under light irradiation.