Fabrication of PVDF-blended ultrafiltration membranes incorporated by chiral mesoporous silica for enantioseparation

• Published in: Journal of industrial and engineering chemistry (Seoul, Korea) Vol. 109; pp. 568 - 577
• Main Authors: Wang, Ting, Huang, Xiao-xing, Wu, Li-guang, Li, Chun-juan, Zhu, Dong-feng
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 25.05.2022; 한국공업화학회
• Subjects: Chiral mesoporous SiO2; Enantioseparation; Mixed-matrix membranes; PVDF; Ultrafiltration; 화학공학; Mixed-matrix membranes; Ultrafiltration; Enantioseparation; PVDF; Chiral mesoporous SiO2
• ISSN: 1226-086X; 1876-794X
• DOI: 10.1016/j.jiec.2022.02.046

[Display omitted] •The asymmetric helical channel structures caused the chiral features of mesoporous SiO2.•PVDF blended membranes incorporated with chiral mesoporous SiO2 were constructed.•The hydrophilicity and polarity of the PVDF was improved by chiral mesoporous SiO2.•All membranes containing chiral mesoporous SiO2 had enantioseparation performance.•The addition of β-CD would further improve the enantioselectivity of the membranes. Novel poly(vinylidene fluoride) (PVDF) ultrafiltration membranes blending with chiral mesoporous SiO2 materials were constructed to improve the anti-fouling and separation performance of PVDF-blended membranes. The formation of asymmetric mesoporous structure of chiral mesoporous SiO2 caused their large hydrophilic surface and significant chiral features, which enhanced the hydrophilicity and polarity of the resulting PVDF membranes blended with chiral mesoporous SiO2. So, the PVDF-blended membranes containing chiral mesoporous SiO2 had a high permeation performance and anti-fouling property. After blending with chiral mesoporous SiO2, the maximum flux of membranes exceeded 500 L·m−2·h−1 and was 6.5-fold higher than that of neat PVDF. Due to the stereo-specific interaction between enantiomers and chiral recognition sites introduced by chiral mesoporous SiO2 in the membranes, all PVDF-blended membranes had evident enantioseparation performance for DL-racemic tryptophan. The C-SiO2-20/PVDF-blended membranes had the highest enantioseparation performance under the same addition content and the maximum enantiomeric excess (e.e.%) was more than 20 %. Given the strong stereo-specific interaction and hydrogen bonding between d-tryptophan and β-cyclodextrin (β-CD), the addition of more β-CD would introduce more chiral recognition sites into the membranes, thereby enhancing the enantioseparation performance of the membranes for d-tryptophan. The maximum e.e.% of C-SiO2-20/β-CD/PVDF-blended membranes for the tryptophan enantiomer reached 55%.