Fig. 2: Design, preparation, and spectral analysis of the dual-selective POM-PTFE-Al emitter.
From: A dual-selective thermal emitter with enhanced subambient radiative cooling performance
a Molecular design. FTIR-ATR spectra of POM and PTFE where the main characteristic peaks of C-O-C vibrational absorption/emission of POM are located in the region of the first atmospheric window (8–13 μm), and the C-F vibrational absorption/emission of PTFE mainly in the second atmospheric window (16–25 μm). The red and blue boxes indicate the first and second atmospheric window, respectively. b Hierarchical nano-micro structure design. Simulation of the scattering efficiency of POM fibers (left) and PTFE particles (right) over the wavelength range of 0.3–2.5 μm with the fiber diameter varied from 0.2 to 2 μm and the particle diameter varied from 0.2 to 3 μm. c Schematic of the dual-selective POM-PTFE emitter. d, e Photograph (d scale bar = 20 cm) and SEM images e of the synthesized POM-PTFE film, which has a bead-like fiber structure consisting of POM nanofibers and PTFE micro-particles. Scale bars in e = 20 μm and 2 μm (inset). f Spectral response of a POM-PTFE film covered Al foil (POM-PTFE-Al) in the 0.3–25 μm waveband, including the solar reflectance (black line) and MIR emittance (red line). The inset shows the statistical distribution of the diameters of the POM nanofibers and PTFE particles inside the POM-PTFE film. g Spectral response of POM-PTFE-Al film before and after intense UV and outdoor exposure tests. Source data are provided as a Source Data file.
