(349c) Fabrication of Metal-Organic Framework (MOF)-Polymer Composite Thin Films for Piezoelectricity-Based Applications

Metal-organic frameworks (MOF)-polymer composite materials have gained tremendous interest as polymers have been shown to enhance MOF properties and vice-versa. In this study, we synthesize a composite of a zirconium-based MOF- UiO-66 and a piezoelectric polymer poly (vinylidene fluoride-trifluoro ethylene) (P(VDF-TrFE)). Piezoelectric polymers are flexible, easy to process, and biocompatible and are useful in sensors, actuators and nanogenerators as they convert mechanical energy to electrical energy.

In this work, a meniscus-guided coating technique also known as solution shearing was used to fabricate thin films of the MOF-polymer composite. Unlike the conventional thin film fabrication process (solvothermal, vapor deposition), large-area and continuous MOF-polymer thin films can be fabricated within a few minutes. We also studied the effect of the amount of polymer loading into the MOF cavity on the crystallinity, surface morphology, porosity, and piezoelectric performance of the thin films. With the incorporation of P(VDF-TrFE) the surface coverage of the films was enhanced. Among the composites with different relative wt. % of MOF and polymer, 31 wt. % UiO-66 MOF-polymer composite yielded the highest output voltage (15 V) when pressure was applied. This study provides an avenue to synthesize large-area thin films of MOF-polymer composites with different functionality for various applications by using the process of solution shearing.