Macroscopic alignment of metal–organic framework crystals: recent advances and perspectives on sustainability

Abstract

The commercial applications of crystalline materials that exhibit highly anisotropic crystal structures and physical properties require performance optimization through the control of size, morphology, and macroscopic alignment of the crystals. For instance, recent investigations have been focused on the development of methods to control the orientation of metal–organic frameworks (MOFs), a class of porous, crystalline coordination solids with potential applications in various green technologies. In general, the in situ alignment method involves the controlled growth of MOF crystals along a preferred crystallographic orientation, while post-synthetic approaches utilize external driving forces to align pre-synthesized MOF crystals. This review presents recent advancements in the alignment processes and their implications for various applications and sustainability, offering a promising outlook for the future of green technologies.