# Effects of Isothermal Treatment on AgZIF‐62: Implications on Porosity, Separations, and Grain Boundary Defect Removal

## TL;DR

This study explores how isothermal treatment affects the porosity and structure of ZIF-62 glasses, impacting their gas separation properties and morphology.

## Contribution

The study reveals how isothermal treatment influences porosity and morphology of ZIF-62 glasses, enabling controlled production.

## Key findings

- The transition from crystal to glass increased fractional free volume from 3.78% to 5.50%.
- Isothermal treatment impeded CO2, N2, and propene accessibility by 59–79%.
- Longer isothermal hold times improved grain coalescence while shorter times retained original morphology.

## Abstract

Glasses derived from metal‐organic frameworks (MOFs) combine the processing benefits of glassy materials with the accessible and selective porosity of MOFs, with potential applications in gas separation and electronics. Establishing control over MOF glasses requires an accurate understanding of how processing parameters will affect the resulting glass properties. To advance this understanding, the effect of isothermal melt treatment conditions on the porosity and morphology of ZIF–62 is investigated. It is demonstrated that the transition from crystal to glass increased in fractional free volume (3.78 ± 0.07% to 5.50 ± 0.03%, respectively) while impeding the accessibility of CO2, N2, and propene by 59–79%. It is demonstrated that the change in pore volume is independent of isothermal hold times. In contrast, isothermal hold time allows control over glass morphology, where short treatments retained more original morphological characteristics, while longer treatments improved grain coalescence.

This study determines the effects of melt conditions and time on agZIF‐62's pore volume, accessible porosity, morphology, and coalescence for controlled production of ZIF‐62 glasses.© 2026 WILEY‐VCH GmbH