Sisi Ma,Ligang Lin,Qi Wang,Yuhui Zhang,Honglei Zhang,Yixin Gao,Lin Xu,Fusheng Pan,Yuzhong Zhang
A simple and effective strategy to simultaneously enhance the permeability and antifouling properties of ethylene vinyl alcohol (EVAL) membrane was developed based on the bioinspired natural cleaner, cilia. Taking clue from the self-cleaning effect of cilia, supramolecular polyrotaxanes (PRs) with sliding and rotating cyclic molecules along linear chains were synthesized using azide-alkyne click chemistry. Cilia-like PRs were incorporated into EVAL matrix in the fabrication of modified EVAL membranes. Cilia-like structures protruding from the membrane surface have been observed by SEM, TEM and AFM. By imitating natural ciliary movements, these structures provided a proactive self-cleaning system to remove the foulants. The introduction of cilia-like PRs enhanced the surface roughness and hydrophilicity, and significantly enhanced permeability by 55.3% compared to raw EVAL membrane. Moreover, the membrane modified with cilia-like PRs showed an excellent antifouling property with a lower water flux decline (12.6%) and higher water flux recovery (94%) in dynamic fouling tests. Furthermore, this modified membrane develops the scope of bioinspired membranes, inspiring more attractive potential applications in self-cleaning materials, dynamic membranes and supramolecular machines.
This work was expected to develop a new loose NF membrane with facile materials to conduct dye/salt separation and endow it with versatile capacities to offer an applicable solution to treat textile wastewater. Ethylene vinyl alcohol (EVAL) was first chosen to fabricate loose nanofiltration (NF) membrane through non-solvent induced phase separation (NIPS) method. Besides, MIL-101(Fe) showed outstanding photocatalytic capacity in degrading organic molecules while a low-cost bio-inspired coating, catechol, was utilized to modify MIL-101(Fe). A combination of modified MIL-101(Fe) and EVAL could have a high water permeability (43.2 L·m −2 ·h −1 ·bar −1 ) with superior rejection to small molecule negative charged dyes (Chlorazol black T: 99.8%, Congo Red: 99.7%, Eriochrome black T: 98.4%) and low rejection to various salts (Na 2 SO 4 : 4.8 %, NaCl: 2.1 %, MgCl 2 : 2.9%, MgSO 4 : 4.9% and CaCl 2 : 3.3%). Meanwhile, the EVAL loose NF membrane with the best performance had excellent antifouling capacity and long-term stability in EBT/Na 2 SO 4 separation. Moreover, the membrane could degrade dyes to self-clean the membrane surface through photocatalytic process, which originated from the Fe-O clusters in MIL-101(Fe).
危险品化学品经营许可证（带存储）