Synthesis and characterization of high-flux ZIF-90/ poly-dimethyldiethoxysilane (PDMDES) mixed matrix membrane for enhanced pervaporation recovery of alcohols

In the present research, micron-sized zeolitic imidazolate framework-90 (ZIF-90) particles were synthesized utilizing an adapted synthesis route and subsequently incorporated into the poly-dimethyldiethoxysilane (PDMDES) polymer to fabricate ZIF-90/PDMDES mixed matrix membrane (MMM) with an objective to ach-ieve enhanced pervaporation performance for the efficient separation of alcohols from aqueous solutions. Comprehensive characterization techniques were employed to investigate the properties of the ZIF-90 particles and the newly fabricated ZIF-90/PDMDES MMMs. Encouraging findings revealed that the incorporation of microporous ZIF-90 particles led to notable enhancements in hydrophobicity, alcohol affinity, and thermal stability of the MMMs. Notably, a distinctive cross-sectional morphology of the ZIF-90/PDMDES MMMs were observed at lower ZIF-90 loadings, a phenomenon attributed to the disparity between the ZIF-90 particle size and the inherent thickness of the PDMDES layer. Systematic evaluations were conducted to ascertain the influence of ZIF-90 loadings, feed concentration, and operational temperature on the pervaporation performance of ZIF-90/ PDMDES MMMs. Accordingly, the optimal separation performance was obtained at the ZIF-90 loading of 5 wt% when separating ethanol from 5 wt% ethanol aqueous solution at 40 degrees C, yielding an impressive total flux of 6.51 kg center dot m(-2) h(-1), a separation factor of 7.29, a PSI of 40.95 kg center dot m(-2) h(-1), and an ethanol permeability of 7.45 x 10(4) Barrer.