Construction of covalently-bonded tannic acid/polyhedral oligomeric silsesquioxanes nanochannel layer for antibiotics/salt separation

• Published in: Journal of membrane science Vol. 623; p. 119044
• Main Authors: Shen, Yu-Jie, Kong, Qing-Ran, Fang, Li-Feng, Qiu, Ze-Lin, Zhu, Bao-Ku
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.04.2021
• Subjects: Layer-by-layer; Polyhedral oligomeric silsesquioxanes (POSS); Separation; Tannic acid; Tannic acid; Polyhedral oligomeric silsesquioxanes (POSS); Separation; Layer-by-layer
• ISSN: 0376-7388; 1873-3123
• DOI: 10.1016/j.memsci.2020.119044

Nanoscale permeation channels are a key factor for molecules or/and ions separation in membrane field. In this work, molecular deposition strategy is designed to construct high-performance nanochannel separation layer for selective separation of small molecules. Herein, octaammonium polyhedral oligomeric silsesquioxane (8NH3Cl-POSS) and tannic acid (TA), two kinds of multifunctional molecules with a size of about 1 nm, were used to prepare robust and perm-selective composite membrane through covalently-bonded layer-by-layer (LbL) self-assembly method. The optimized TA-POSS composite membrane exhibited a narrowed pore size distribution from 0.3 to 1.6 nm with a high water permeance of 21 L m−2 h−1 bar−1. The membrane showed desirable rejection of antibiotics (>90%) and enabled to separate them from NaCl solution. In addition, TA-POSS composite membrane showed outstanding stability due to the high degree of crosslinking between TA and 8NH3Cl-POSS and their rigid structures. This work gives a novel and green strategy to construct nanochannel composite membranes, which can efficiently separate molecules and salt. [Display omitted] •TA-POSS membrane was prepared by covalently-bonded LbL self-assembly method.•The membrane showed a permeance of 21 LMH/Bar with MWCO of 440 Da.•The membrane enabled to efficiently separate the antibiotics and NaCl solution.•The membrane showed good stability performance due to the cross-linked structure.