PolyHIPE Composites for Latent Heat Storage: Flexibility and Enhanced Light to Heat Conversion

Emulsion-templated, phase change material-encapsulated, mono-lithic polyHIPE composites are promising for latent heat storage, but their rigidity and low energy conversion limit the real applications. Here, we report the fabrication of phase-change material (octadecane, OD)-encapsulated polyHIPE composites with good flexibility and enhanced light/electro to heat conversion from surfactant-free emulsions. The composites were formed from interfacial cross-linking between isocynate and surface-modified carbon nanotubes and aminated cellulose nanocrystals which served as OD-in-water emulsion stabilizers. The resulting composites were flexible and exhibited robust compression (without failure even at 70% compressive strain), good encapsulation, high heat capacity (up to 220 J/g), and good reusability. Moreover, the composites exhibited enhanced light/electro to heat conversion efficiency (up to 90%), even at a low carbon nanotube content of around 0.1 wt %. These advantageous properties enabled the polyHIPE composites to be excellent candidates for latent heat storage and for light/electro to heat conversion.