To effectively mitigating intense impact and blast waves, a novel protection mechanism is proposed in this study where a significant amount of the incident energy can be temporarily captured as potential energy in a nonwetting liquid-nanoporous material system, thereby weakening the peak pressure and elongating the impact pulse. When the pressure of a compressive wave traveling in a liquid overcomes the capillary resistance, the liquid molecules quickly intrude into nanopores while retaining highly compressed form. The incident energy is thus captured (temporarily stored) in nanopores in the form of potential energy of intercalated water molecules, and then gradually released upon unloading (which makes the system reusable). Comparing with other energy absorption materials, the present system has the unique advantage of low activation pressure and high energy density. Using comprehensive molecular dynamics (MD) simulations, the effects of several key parameters (e.g., impact velocity, nanopore size, and pore composition) on energy capture are investigated, and the molecular mechanism is elucidated. The findings are qualitatively validated by a parallel blast experiment on a zeolite/water system.
The work is supported by National Science Foundation (CMMI-0643726 and ECCS-1028010), DARPA (W91CRB-11-C-0112), National Natural Science Foundation of China (11172231), and Changjiang Scholar Program from Ministry of Education of China.
- Energy capture
- Impacting wave
- Nanoconfined liquids