Energy absorption and storage of nanofluidic solid-liquid composite material under high strain rates

Efficient energy absorption and dissipation are crucial for the development of novel protective materials under intensive dynamic loadings. Nanofluidic solid-liquid composite materials (NLCs) provide a promising pathway to engineer such materials owing to their rapid and reversible energy absorption and storage performance. In this study, we conducted systematic experiments on nanoporous SiO₂ based NLCs to gain a better understanding of the dynamic mechanical behavior and the underlying energy absorption and storage mechanisms under compressions with varying strain rates. Our findings indicate that the energy absorption in terms of dissipation and storage under the repeat compressive loadings includes two stages. The initial stage indicates the maximum energy absorption capacity, which is efficiently improved by the adding electrolyte solution and the retreatment. The stable energy absorbing stage represents the reversible energy absorption and storage capacity of the NLCs. Based on the noticeable strain rate effect, a three-stage mechanism is proposed to explain the significant increase of energy absorption capacity with the varying compressive strain rates. The superior reusable energy absorption capacity of NLCs holds great promise for their use as excellent energy-absorbing materials under intensive impulsive loadings.