Compact Thermal Actuation by Water and Flexible Hydrophobic Nanopore
Efficient and compact energy conversion is at the heart of sustainable development of humanity. In this work it is demonstrated that hydrophobic flexible nanoporous materials can be used for thermal-to-mechanical energy conversion when coupled with water. In particular, a reversible nonhysteretic wetting-drying (contraction-expansion) cycle provoked by periodic temperature fluctuations was realized for water and superhydrophobic nanoporous MOF Cu2(tebpz) (tebpz = 3,3',5,5'-tetraethyl-4,4'-bipyrazolate). Thermal-to-mechanical conversion efficiency of 30% was directly recorded by high-precision PVT-calorimetry, while operational cycle was confirmed by in operando neutron scattering. The obtained results provide an alternative approach for compact energy conversion exploiting solid-liquid interfacial energy in nanoscopic flexible heterogeneous systems.
Energy storage, diffraction, metal-organic framework