Related Experiment Video
Updated: May 23, 2025
10:19
Three-Dimensionally Printed Microfluidic Cross-flow System for Ultrafiltration/Nanofiltration Membrane Performance Testing
Published on: February 13, 2016
11.2K
Fluorinated Covalent Organic Framework Antifouling Nanofiltration Membranes Through Defect Engineering.
Qingyuan Liu1, Shiyi Zhu1, Chao Yang1
1Key Laboratory for Green Chemical Technology of Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China.
Small (Weinheim an Der Bergstrasse, Germany)
|March 10, 2025
Summary
This study introduces a novel method to enhance covalent organic framework (COF) membranes for water treatment by grafting fluorinated chains. The resulting membranes exhibit superior antifouling properties and high separation performance.
Area of Science:
- Materials Science
- Chemical Engineering
- Environmental Science
Background:
- Covalent organic framework (COF) membranes show potential for water treatment.
- Improving antifouling properties is crucial for practical COF membrane applications.
- Grafting fluorinated chains is a promising strategy but faces challenges due to limited grafting sites.
Purpose of the Study:
- To develop an effective strategy for grafting fluorinated chains onto COF membranes.
- To create COF membranes with enhanced antifouling properties and high separation performance.
- To investigate the regulation of perfluoroalkyl chain content for optimized performance.
Main Methods:
- Defect engineering was used to create free amino groups on the COF membrane surface via Schiff-base reactions.
- Perfluoroalkyl chains were grafted onto the COF membrane using perfluorooctanoyl chloride.
- The content of grafted chains was controlled by regulating the amount of free amino groups.
Main Results:
- The fluorinated COF membrane demonstrated superior antifouling performance against oil/water emulsions and humic acid, with a flux recovery ratio (FRR) of approximately 98% and a flux decline ratio (DRt) of 10%.
- The membrane achieved high water permeance (≈115 L m⁻² h⁻¹ bar⁻¹).
- High salt/dye selectivity was maintained alongside the improved antifouling characteristics.
Conclusions:
- Defect engineering provides an effective route to introduce grafting sites for fluorinated chains on COF membranes.
- The developed fluorinated COF membranes offer excellent antifouling properties and high separation efficiency for water treatment.
- This approach is applicable to the development of advanced organic molecular sieve membranes.
