When inorganic nanoporous aerogels (such as alumina, zirconia, or silica aerogels) operate in high-temperature thermal environments, their primary physical challenge is microstructural coarsening and specific surface area degradation. At elevated temperatures, solid skeletons composed of nanoscale particles possess large curvature radius variations and high surface energies, driving spontaneous mass transport where smaller particles dissolve and larger particles grow—a process known as Ostwald ripening and grain growth. Investigating grain growth kinetics and ripening suppression mechanisms in nanoporous networks under high-temperature fields represents a central topic in thermodynamics and structural physics.

Thermodynamically, the surface chemical potential of a nanoparticle relates to its radius of curvature. According to the Gibbs-Thomson effect, smaller radii of curvature correspond to higher local surface chemical potentials. Activated by high thermal fields, chemical potential gradients drive atoms to detach from high-curvature particle necks or small crystallites and migrate via surface or grain boundary diffusion to deposit at lower-curvature contact necks, causing fine nanopores to close and the framework to coarsen.

To suppress ripening-induced structural collapse at high temperatures, materials physicists employ stabilization strategies. The physical approach involves introducing trace high-melting-point heteroatom dopants onto nanoparticle surfaces, establishing stable surface chemical blocking layers, or constructing hierarchical heterostructured nanocomposites.

These surface modifications lower local surface free energies and introduce spatial steric hindrances or diffusion activation barriers at interparticle contact necks. These diffusion barriers impede cross-interface atomic migration at elevated temperatures, raising the kinetic activation energy for grain growth. Regulating atomic diffusion kinetics and curvature-driven mass transport equations maintains the long-term structural stability of aerogel nanoporous networks under extreme thermal conditions.