Tuning the balance between dispersion and entropy to design temperature-responsive flexible metal-organic frameworks

Author(s)
J. Wieme, K. Lejaeghere, G. Kresse, V. Van Speybroeck
Abstract

Temperature-responsive flexibility in metal-organic frameworks (MOFs) appeals to the imagination. The ability to transform upon thermal stimuli while retaining a given crystalline topology is desired for specialized sensors and actuators. However, rational design of such shape-memory nanopores is hampered by a lack of knowledge on the nanoscopic interactions governing the observed behavior. Using the prototypical MIL-53(Al) as a starting point, we show that the phase transformation between a narrow-pore and large-pore phase is determined by a delicate balance between dispersion stabilization at low temperatures and entropic effects at higher ones. We present an accurate theoretical framework that allows designing breathing thermo-responsive MOFs, based on many-electron data for the dispersion interactions and density-functional theory entropy contributions. Within an isoreticular series of materials, MIL-53(Al), MIL-53(Al)-FA, DUT-4, DUT-5 and MIL-53(Ga), only MIL-53(Al) and MIL-53(Ga) are proven to switch phases within a realistic temperature range.

Organisation(s)
Computational Materials Physics
External organisation(s)
Ghent University
Journal
Nature Communications
Volume
9
No. of pages
10
ISSN
2041-1723
DOI
https://doi.org/10.1038/s41467-018-07298-4
Publication date
11-2018
Peer reviewed
Yes
Austrian Fields of Science 2012
Materials physics
Keywords
Portal url
https://ucris.univie.ac.at/portal/en/publications/tuning-the-balance-between-dispersion-and-entropy-to-design-temperatureresponsive-flexible-metalorganic-frameworks(ead05296-f0b5-42a6-88fb-67d587435f76).html