Within high-temperature engineering environments exceeding 1,000°C (such as hypersonic thermal protection systems, nuclear reactor cores, and high-temperature industrial furnaces), the dominant heat transfer mechanism transitions from conduction and convection to thermal radiation. According to Planck's law of blackbody radiation, high-temperature surfaces emit electromagnetic energy centered within the infrared spectrum (1 to 30 $mutext{m}$). In conventional dense media, radiative heat transfer causes thermal leakage via photon transmission or lattice vibrational coupling. However, aerogels suppress radiative heat flux under extreme high-temperature thermal loads through near-field micro-nano localized resonances and Coulomb damping coupling mechanisms.

When infrared thermal radiation photons strike the aerogel micro-network, because the solid skeletal features (nanoparticle diameters of 2–5 nm) and pore dimensions (20–50 nm) are smaller than the primary wavelengths of incident infrared photons (~5–10 $mutext{m}$), photons interact with the nanoscale solid boundaries via electromagnetic scattering and near-field interactions. The electromagnetic oscillating energy of the photon couples with polarization charges on the surfaces of the nanoparticles.

During this near-field electromagnetic coupling process, the electron clouds and ionic lattices within the solid nanoscale skeleton undergo polarization oscillations. When opacifying nanoparticles are incorporated into the aerogel matrix, the electromagnetic energy of incident photons is captured by surface charges or confined phonon polaritons and dissipated as thermal energy via microscopic Coulomb damping mechanisms. This damps radiative energy transfer over short length scales.

Furthermore, because aerogels contain numerous alternating solid-skeleton/air-pore refractive index boundaries, incident photons undergo Mie and Rayleigh scattering. This multiple scattering lengthens the effective optical path of photons through the material and introduces interference and phase cancellation effects, suppressing radiant energy flux. By tuning the dielectric permittivity, refractive index dispersion, and particle size distribution of aerogel matrices, physicists engineer electromagnetic bandgaps tailored to specific infrared wavebands, achieving radiative suppression and Coulomb damping under thermal gradients.