Aerogel-involved triple-state viscoelastic fluidic materials enable high-efficiency dual-purpose energy management

Fluidic materials remain in their infancy. Here, we develop triple-state fluids (TSFs) by dispersing superhydrophobic aerogel microparticles into aqueous solutions, creating multiphase systems that integrate solid, liquid, and gaseous states with heterogeneous lyophobic characteristics and dual-mode viscoelasticity. TSFs exhibit low density (0.45 g·cm^-3), low thermal conductivity (0.21 W · m^-1 · K^-1), and a shear viscoelasticity that shifts from the solid-like to the liquid-like in response to strain. They also demonstrate compressive viscoelasticity and energy dissipation in a single compression-rebound cycle, maintaining structural integrity even after 400 cycles. As a colloidal damper medium, TSFs (with a tan δ of 0.2-0.6 over 0-200 Hz) show vibration isolation performance comparable to that of commercial polyurethane foams. The shear viscoelasticity also allows TSFs to be processed into low-thermal-conductivity (0.0274 W · m^-1 · K^-1) coatings for thermal management. Overall, this work establishes a pathway toward space-adaptive, dual-purpose (mechanical and thermal) energy management materials.