Al-fumarate/PVDF-HFP Mixed matrix membrane for water vapor adsorption in industrial drying processes

Metal Organic Frameworks (MOFs) are crystalline porous materials with high surface areas and tunable properties, making them ideal for dehumidification, water recovery, and thermal cooling applications. However, their powder form can limit practical use. Embedding MOFs in polymer matrices can be an effective way to obtain stable composite membranes while preserving adsorption performance. This work focuses on the development of Aluminum-fumarate/poly(vinylidene fluoride-co-hexafluoropropylene) Mixed Matrix Membranes (MMM) for industrial drying cycles. Different membranes with 50–70 wt% MOF loadings were fabricated via solution casting. The effectiveness of the membranes was evaluated by measuring their specific surface area against that of pure MOF. The membrane containing 50 wt% Alfumarate exhibited a low specific area of 390 m2/g (normalized to the MOF content). Unexpectedly the membrane with the highest MOF content showed a drastic reduction in the specific area (170 m2/g). The best performing sample resulted the 67 wt% MOF membrane, which achieved a specific area of 890 m2/g. In this case, the embedded MOF particles retained about 90 % of the surface area of pure MOF (1010 m2/g). Further in-depth analyses were conducted on this optimal sample allowing to assess its physical, mechanical, and functional properties. In particular, the water vapor adsorption capacity was found to be ~ 37 gH2O/gMOF at p/p0 0.9. Using the simple methodology proposed, it was possible to develop a mixed matrix membrane that expresses the adsorption properties of the active material while solving powder management issues.