posted on 2023-11-30, 21:40authored byLiam J.
W. Johnson, Diego Mirani, Andrea Le Donne, Luis Bartolomé, Eder Amayuelas, Gabriel A. López, Giulia Grancini, Marcus Carter, Andrey A. Yakovenko, Benjamin A. Trump, Simone Meloni, Paweł Zajdel, Yaroslav Grosu
Flexible nanoporous materials are of great interest for
applications
in many fields such as sensors, catalysis, material separation, and
energy storage. Of these, metal–organic frameworks (MOFs) are
the most explored thus far. However, tuning their flexibility for
a particular application remains challenging. In this work, we explore
the effect of the exogenous property of crystallite
size on the flexibility of the ZIF-8 MOF. By subjecting hydrophobic
ZIF-8 to hydrostatic compression with water, the flexibility of its
empty framework and the giant negative compressibility it experiences
during water intrusion were recorded via in operando synchrotron irradiation. It was observed that as the crystallite
size is reduced to the nanoscale, both flexibility and the negative
compressibility of the framework are reduced by ∼25% and ∼15%,
respectively. These results pave the way for exogenous tuning of flexibility in MOFs without altering their chemistries.