Synthesis and Mechanical Properties of sub 5-μm PolyUiO-66 Thin Films on Gold Surfaces

Metal-organic framework (MOF) thin films currently lack the mechanical stability needed for electronic device applications. Polymer-based metal-organic frameworks (polyMOFs) have been suggested to provide mechanical advantages over MOFs, however, the mechanical properties of polyMOFs have not yet been characterized. In this work, we developed a method to synthesize continuous sub-5 mu m polyUiO-66(Zr) films on Au substrates, which allowed us to undertake initial mechanical property investigations. Comparisons between polyUiO-66 and UiO-66 thin films determined polyUiO-66 thin films exhibit a lower modulus but similar hardness to UiO-66 thin films. The initial mechanical characterization indicates that further development is needed to leverage the mechanical property advantages of polyMOFs over MOFs. Additionally, the demonstration in this work of a continuous surface-supported polyUiO-66 thin film enables utilization of this emerging class of polyMOF materials in sensors and devices applications.

Automated summary

Metal-organic framework (MOF) thin films currently lack the mechanical stability needed for electronic device applications. This study developed a method to synthesize polyUiO-66(Zr) films and investigated their mechanical properties compared to UiO-66 thin films. The results showed that polyUiO-66 films have a lower modulus but similar hardness to UiO-66 films. Further development is needed to fully utilize the mechanical advantages of polyMOFs over MOFs. The continuous surface-supported polyUiO-66 thin films demonstrated in this work enable potential applications in sensors and devices.