Effects of structural crystallinity and defects in microporous Al-MOF filled chitosan mixed matrix membranes for pervaporation of water/ethanol mixtures
RIS ID
119910
Abstract
A new two-dimensional microporous metal organic framework (MOF), Al-MOF, [Al(OH)(MBA)] (CYCU-7, MBA = diphenylmethane-4,4′-dicarboxylate anion) and its reported analogue, [Al(OH)(SBA)] (CAU-11, SBA = 4,4′-sulfonyldibenzoate anion), have been synthesized using hydrothermal and solvothermal method s, respectively, and their structural crystallinities and defect porosities were carefully controlled and characterized by N 2 sorption isotherms and 27 Al solid-state nuclear magnetic resonance measurements. Interestingly, the MOF synthesized by the ethanol-based solvothermal method (CYCU-7) show a significant degree of linker-missing defects compared to that synthesized by the water-based hydrothermal method (CAU-11). We further incorporated the synthesized CYCU-7 and CAU-11 with chitosan (CS) biopolymer to make CYCU-7@CS and CAU-11@CS mixed matrix membranes (MMMs) with the loading amount of MOF 2.5, 5.0, or 10 wt%. The as-prepared CYCU-7@CS and CAU-11@CS MMMs were applied for separation of water/ethanol mixtures through the pervaporation process, and the effects of the structural properties (e.g. crystallinity and defects) of CYCU-7 and CAU-11 on the separation performance are studied. It is found that defect-rich CYCU-7@CS MMMs exhibit higher flux, while CAU-11@CS MMMs with higher crystallinity exhibit a higher separation factor. In addition, the CAU-11@CS MMM with 5.0 wt% loading of CAU-11 displays the best separation performance (separation factor = 2741 and flux = 458 g/m 2 h).
Publication Details
Vinu, M., Senthil Raja, D., Jiang, Y., Liu, T., Xie, Y., Lin, Y., Yang, C., Lin, C., Alshehri, S. M., Ahamad, T., Salunkhe, R. R., Yamauchi, Y., Deng, Y. & Wu, K. C.-W. (2018). Effects of structural crystallinity and defects in microporous Al-MOF filled chitosan mixed matrix membranes for pervaporation of water/ethanol mixtures. Journal of the Taiwan Institute of Chemical Engineers, 83 143-151.