Liquid phase blending of metal-organic frameworks

Abstract

The liquid and glass states of metal–organic frameworks (MOFs) have recently become of interest due to the potential for liquid-phase separations and ion transport, alongside the fundamental nature of the latter as a new, fourth category of melt-quenched glass. Here we show that the MOF liquid state can be blended with another MOF component, resulting in a domain structured MOF glass with a single, tailorable glass transition. Intra-domain connectivity and short range order is confirmed by nuclear magnetic resonance spectroscopy and pair distribution function measurements. The interfacial binding between MOF domains in the glass state is evidenced by electron tomography, and the relationship between domain size and Tg investigated. Nanoindentation experiments are also performed to place this new class of MOF materials into context with organic blends and inorganic alloys.

Metal-Organic Framework Crystal-Glass Composites

“…The emergence of diffuse scattering at q~0.9-1.2 Å −1 at this temperature indicated melting, consistent with prior literature ( Supplementary Fig. 11a, b) 32 .…”

“…The sample was held at 450°C for 10 min and then cooled back to room temperature under Ar protection. The CGCs are referred to as (Crystal) X (a g Glass-matrix) Y , in line with our previous publication 32 . Pure phase crystals were also subjected to the same ball milling and thermal treatment as a benchmark 32 .…”

Unraveling the effects of linker substitution on structural, electronic and optical properties of amorphous zeolitic imidazolate frameworks-62 (a-ZIF-62) glasses: a DFT study

“…14,15 Apart from the static structure analysis, a dynamic tracing of the melting behaviour of ZIF-4 is also provided by the results that combine the rst-principles molecular dynamics with in situ variable temperature X-ray experiments. 16 The whole formation process of ZIF-glass, however, is still in absence. The further exploration discovers that the glass-forming ability (GFA) could be tuned by adjusting the chemistry of the initial structure.…”

A New Dimension for Coordination Polymers and Metal–Organic Frameworks: Towards Functional Glasses and Liquids

“…MOF glass blends are prepared by mixing the MOF candidates through ball milling followed by heating the physical mixture above the T m value . For example, crystals of Zn‐ZIF‐4 and Zn‐ZIF‐62 are physically mixed and heated to the T m value of Zn‐ZIF‐62.…”