Metal–organic framework growth at functional interfaces: thin films and composites for diverse applications

Porous metal-organic frameworks (MOFs) are highly ordered crystalline materials prepared by the self-assembly of metal ions with organic linkers to yield low density network structures of diverse topology. MOFs have attracted considerable attention over the last decade due to their facile preparation, tunable pore metrics and the ease of functionalisation of their internal surfaces, such that designer frameworks with exceptional properties for application in gas-storage, separation of small molecules, heterogeneous catalysis and drug delivery are becoming commonplace. For any material to find practical utility however, there is a need for processing and formulation into application-specific configurations. One way to do this is to prepare composite materials where the MOF is supported on a planar substrate or some other shaped body through interaction with functional groups at the support interface. This is a rapidly developing research area, and this review provides an overview of the diverse MOF composite materials prepared up to now, organised by interface type. The importance of the interface is explored within each section and while the overall emphasis is on applications of the composites, coatings and MOF-based devices, the most widely-used and successful synthetic strategies for composite formation are also presented. (183 references).