Work

Influence of pore-confined water on the thermal expansion of a zinc-based metal–organic framework

Year: 2025

Type: article

Abstract: O molecules triggers a doubling of the thermal expansion coefficient in the direction, where the hydrogen bonds have been removed. Regarding the dynamics of the process, thermal activation in air occurs within 6 hours at a temperature of 50 °C and takes only 30 minutes when heating to 90 °C. In contrast, full rehydration under standard lab conditions (30% relative humidity) requires two days. During the activation/dehydration processes no change of the widths of the X-ray diffraction peaks is observed, which shows that the underlying crystal structure remains intact during the transition processes. Fitting the transformations by the Avrami equation reveals a quasi one-dimensional evolution of the dehydrated areas for the activation process and a more intricate, predominantly two-dimensional mechanism for the rehydration.

Source: Journal of Materials Chemistry C

DOI: 10.1039/d5tc01746g