RESUMO
Finding appropriate stimuli for controlling the breathing behavior of flexible metal-organic frameworks (MOFs) is highly challenging. Herein, we report the solvent-induced changes in the particle size and stability of different breathing phases of the MIL-53 series, a group of flexible MOFs. A water/dimethylformamide (DMF) ratio is tuned to synthesize members of the MIL-53 series which have different behaviors. The breathing is explored by high-pressure methane sorption tests. Increasing DMF concentration decreases MOF particle size and increases the stability of the porous phases, boosting the 5.8-65â bar sorption difference of methane, which is required for natural-gas delivery.
RESUMO
Metal-organic frameworks (MOFs) have gathered tremendous interest among researchers for their potential applications such as in storage and separation. While some progress has been made towards shaping of MOFs to realize industrial applications, the mechanical properties of MOFs remain more or less unexplored. Over the last decade, this area has witnessed a steady growth in terms of understanding the mechanical stability of MOFs and its consequence on their performance. In this review, the mechanical properties of the reported macroscopic shaped MOF structures (mainly granules, pellets, tablets, monoliths, and gels) are discussed. Conclusions are then drawn to determine which shapes and shaping techniques promise to meet industrial requirements on the basis of mechanical stability. Finally, future research directions are proposed to improve our understanding, and possibly enhance stability, by correlating the properties from microscopic single-crystalline level to the industrially relevant macroscopic polycrystalline scale.