Microporous 3D aluminum MOF doped into chitosan‐based mixed matrix membranes for ethanol/water separation

Abstract

An aluminum metal–organic framework (Al‐MOF), [Al(OH)(BPDC)] (DUT‐5; BPDC = Biphenyl‐4,4′‐dicarboxylate), was synthesized using solvothermal reactions. The high surface area and micropores (approximately 1.2 nm) of DUT‐5 were characterized using N2 gas sorption measurements. The thermal stability of DUT‐5 and its phase purity were also investigated. The different amounts of DUT‐5 (0.1, 0.15, and 0.2 wt%) were successfully incorporated into the chitosan (CS) polymer to prepare a mixed matrix membrane (MMM) for the pervaporation of water/ethanol at 25°C. In particular, when 0.15 wt% of DUT‐5 was loaded, the DUT‐5@CS MMMs displayed excellent permeability and selectivity in ethanol/water separation. The results indicated that compared with pristine chitosan membranes, the flux of DUT‐5@CS membranes with 0.15 wt% loading significantly increased from 315 to 378 (g/m2 h−1) and the separation factor from 347 to 3,429. These promising results of the microporous Al‐MOF doped into chitosan MMMs reveal its good application potential for the bio‐ethanol separation processes.

Fast Water Transport in UTSA‐280 via a Knock‐Off Mechanism

“…These measurements were executed using a feed solution comprising 90 wt % ethanol at various temperatures (303, 313, 323, and 333 K). The pervaporation results for the UTSA‐280 membranes, based on mass flux and water permeability, are presented in Figure 3b and S6, alongside comparative data from other MOF‐based membranes [42–52] . Comprehensive details of these membranes, including thickness and water permeability, are summarized in Table S3.…”

“…The pervaporation results for the UTSA-280 membranes, based on mass flux and water permeability, are presented in Figure 3b and S6, alongside comparative data from other MOF-based membranes. [42][43][44][45][46][47][48][49][50][51][52] Comprehensive details of these membranes, including thickness and water permeability, are summarized in Table S3. The UTSA-280 membrane exhibits an exceptional water-toethanol separation factor (33,201), thereby surpassing the performance of both pure MOF membranes and MOFbased mixed matrix membranes.…”

Recent advances and applications of nanostructured membranes in water purification

“…The DUT-5@CSDUT-5@CS membranes with 0.15wt% loading showed a significant increase in permeability and separation factor compared to the CS membrane. These promising results indicate the potential of using microporous Al-MOF in chitosan MMMs for bioethanol separation processes [ 86 ]. Fang et al developed a zirconium-based metal-organic framework (MOF) membrane for wastewater separation.…”

Recent Advances of Pervaporation Separation in DMF/H2O Solutions: A Review

“…Some aluminum MOFs, including MIL-53 [ 91 , 92 ], MIL-96 [ 93 ], NH2-MIL-101 [ 94 , 95 ], CAU-21-ODB [ 96 ] and NH2-MIL-53 [ 94 , 97 ], are incorporated into polymer matrices. The successfully application of various aluminum MOFs such as DUT-5 [ 98 ], CAU-1 [ 99 ] and MIL-53 [ 100 ] in MMMs contributes into flux increment in the pervaporation study. However, these MOF-based membranes are only applied in ethyl acetate–water [ 101 ], dehydration of acetic acid and ethanol [ 102 ].…”