Reactive Extrusion Printing for Simultaneous Crystallization-Deposition of Metal-Organic Framework Films

Reactive extrusion printing (REP) is demonstrated as an approach to simultaneously crystallize and deposit films of the metal-organic framework (MOF) Cu₃ btc₂ (btc=1,3,5-benzenetricarboxylate), also known as HKUST-1. The technique co-delivers inks of the copper(II) acetate and H₃ btc starting materials directly on-surface and on-location for rapid nucleation into films at room temperature. The films were analyzed using PXRD, profilometry, SEM and thermal analysis techniques and confirmed high-quality Cu₃ btc₂ films are produced in low-dispersity interconnected nanoparticulate form. The porosity was examined using gas adsorption which showed REP gives Cu₃ btc₂ films with open interconnected pore structures, demonstrating the method bestows features that traditional synthesis does not. REP is a technique that opens the field to time-efficient large-scale fabrication of MOF interfaces and should find use in a wide variety of coating application settings.