Strategies for conversion between metal–organic frameworks and gels

Abstract This review focuses on strategies for conversion between metal–organic frameworks (MOFs) and gels (including organic gels and metal–organic gels). Crystal crosslinking and mismatch growth of MOF particles are two ingenious strategies to convert MOFs into gels. Reaction conditions (such as concentration of reactants and metal–ligand ratio) have great effect on conversion of MOFs and the third strategy is adjustment of key factors. As for transformation of gels into MOFs, gel degradation and dry-gel conversion have been employed to synthesize MOFs with high yield and improved properties such as better catalytic performances and larger surface areas. Growth of MOF films, MOF membranes and polyMOFs is another strategy. This review also analyzes influence of reaction conditions on morphologies and particle sizes of MOFs derived from gels. Some applications of these strategies have been demonstrated in this work. For example, gels obtained by conversion of MOFs can function as outstanding sorbents and MOF membranes prepared through gel layers have been applied to H2/CO2 separation. Moreover, this review also discusses possible mechanisms of conversion between crystalline MOFs and soft gels by different strategies and prospect of developing these strategies.