Force-driven reversible liquid-gas phase transition mediated by elastic nanosponges.

ABSTRACT: Nano-confined spaces in nanoporous materials enable anomalous physicochemical phenomena. While most nanoporous materials including metal-organic frameworks are mechanically hard, graphene-based nanoporous materials possess significant elasticity and behave as nanosponges that enable the force-driven liquid-gas phase transition of guest molecules. In this work, we demonstrate force-driven liquid-gas phase transition mediated by nanosponges, which may be suitable in high-efficiency heat management. Compression and free-expansion of the nanosponge afford cooling upon evaporation and heating upon condensation, respectively, which are opposite to the force-driven solid-solid phase transition in shape-memory metals. The present mechanism can be applied to green refrigerants such as H₂O and alcohols, and the available latent heat is at least as high as 192?kJ?kg^-1. Cooling systems using such nanosponges can potentially achieve high coefficients of performance by decreasing the Young's modulus of the nanosponge.

SUBMITTER: Nomura K 

PROVIDER: S-EPMC6572794 | biostudies-literature | 2019 Jun

REPOSITORIES: biostudies-literature