Enhanced mechanical properties of a metal-organic framework by polymer insertion

The mechanical strength of metal-organic frameworks (MOFs) is highly relevant for their practical applications. In this research, we show that encapsulation of polymer chains into MOF nanochannels can effectively restrain the breakage of coordination bonding in MOFs and inhibit the amorphization under high physical pressure. The hardness of single MOF crystals was greatly improved, which depended on the direction of the inserted polymers, as revealed by nanoindentation analysis. Insertion of polymer chains did not influence the crystal structure of MOFs, which indicates that this approach should be highly promising for improving the mechanical properties of MOFs.