Fig. 3: Terahertz (THz) absorbing mechanism of polydodecyl acrylate coated organohydrogel (PDA@OHG).
From: Organohydrogel-based transparent terahertz absorber via ionic conduction loss
a Absorptivity curves of the 500-μm-thick polydodecyl acrylate (PDA), organohydrogel (OHG), and polyacrylamide (PAM) aerogel in 0.5–4.5 THz band. b Conduction loss (ε”c), polarization loss (ε”p), and the ratio of polarization loss (ε”p/ε”) of the PDA, OHG, and PAM aerogel. c Conductivity spectra of the OHG and PAM aerogel in frequency range of 10−2 Hz to 4.5 THz. Note that there is a break in the frequency range of 106 Hz to 0.5 THz. And it should be mentioned that the PAM aerogel is insulated in 10−2−106 Hz so that its conductivity in 10−2-106 Hz can’t be measured. d Conductivities of the OHG and PAM aerogel at 0.8 THz as a function of temperature. Each error bar represents the standard deviation of 5 measurements. e Schematic illustration of the THz absorbing mechanism of the OHG. EG: ethylene glycol, red balls: oxygen, gray balls: hydrogen, yellow balls: carbon. There are various ions in the OHG, which mainly originate from the dissociation of water and EG molecules, and a small part is the foreign ions from PAM polymer. When THz wave acts on the OHG, these ions are oscillated to generate strong conduction loss, while the water and EG molecules also generate polarization loss to attenuate the THz wave. Source data are provided as a Source Data file.
