Understanding the Glass Transition of Zeolitic Imidazolate Framework Glasses by Physical Aging Experiments
Author
Term
4. Term
Education
Publication year
2023
Submitted on
2023-12-21
Pages
96
Abstract
This master’s thesis examines the underlying mechanisms occurring during the glass transition of ZIF-62 and ZIF-4 glasses. This mechanism is examined by physically aging the glasses, and recording their calorimetric response. A comparison between these glasses was made to an oxide glass and a polymeric glass. The calorimetric response was recorded using DSC. XRD, IR and NMR was used to determine the successful synthesis of crystalline ZIF-62 and ZIF-4 and subsequent analysis of the physically aged glasses. Physical aging experiments, ranging from 6 minutes to 32 hours, was conducted for the ZIF samples, and subsequent comparison to the oxide and polymeric glasses highlighted the short range disorder observed for ZIF glasses. The dynamic nature of the linkers was further confirmed by analysing ball-milled ZIF-62 and cooling the ball-milled sample to 150 K. The data obtained from the physical aging experiments, was further utilised to deconvolute the underlying mechanism of the glass transition. A signature of this mechanism is attributed to changes in short-range structural changes of the glassy materials.
Keywords
ZIF ; Glas ; MOF ; Annealing ; Physical aging
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