(725d) Simultaneous Spray Self-Assembly of Highly Loaded ZIF-8–PDMS Nanohybrid Membranes Exhibiting Exceptionally High Biobutanol-Permselective Pervaporation

The ability to obtain a maximum loading of inorganic nanoparticles while maintaining uniform dispersion in the polymer is the key to the fabrication of mixed-matrix membranes with high pervaporation performance in bioalcohol recovery from aqueous solution. Herein, we report the simultaneous spray self-assembly of a zeolitic imidazolate framework (ZIF)–polymer suspension and a cross-linker/catalyst solution as a method for the fabrication of a well dispersed ZIF-8–PDMS nanohybrid membrane with an extremely high loading. The dispersion uniformity of the fillers and their compatibility always had an important effect on the pervaporation performance of the membranes. The ZIF-8–PDMS membrane showed excellent biobutanol-permselective pervaporation performance. When the ZIF-8 loading was increased to 40 wt%, the total flux and separation factor could reach 4846.2 g/m²h and 81.6, respectively, in the recovery of n-butanol from 1.0 wt% aqueous solution (80 ⁰C). It exhibited an optimal overall pervaporation performance as compared with that of other reported membranes. We found that butanol molecules mainly pass through the inner channel of ZIF-8, whereas water molecules mainly pass through the interface between PDMS and ZIF-8 particles in such ZIF-8–PDMS membranes with an extremely high loading. In view of the versatile architectures and customizable chemical functionalities of MOF materials, as well as the simplicity, speed, and reproducibility of the spray self-assembly technique, this technology may contribute to the preparation of various MOF hybrid membranes and extend the use of these membranes to industrial applications.