Authors: Keita Nomura, Hirotomo Nishihara, Masanori Yamamoto, Atsushi Gabe, Masashi Ito, Masanobu Uchimura, Yuta Nishina, Hideki Tanaka, Minoru T. Miyahara, Takashi Kyotani
Published: 2019-06-17
DOI: 10.1038/s41467-019-10511-7
Source: Full article
AbstractNano-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.