fig7

Figure 7. (A) UV-vis-NIR spectra of the CPCMs; (B) Surface temperature-time curves of the CPCMs; (C) infrared thermal images of the CPCMs during the heating stage; and (D) infrared thermal images of the CPCMs during the cooling stage. UV-vis-NIR: Ultraviolet-visible-near-infrared; CPCMs: composite phase change materials; PHE: PEG/HDI/EG; PHAE: PEG/HDI/APP/EG; PHHE: PEG/HDI/HAPP/EG; PEG: polyethylene glycol; HDI: hexamethylene diisocyanate; APP: ammonium polyphosphate; EG: expanded graphite; HAPP: hydroxylated ammonium polyphosphate.