Design Principles for PFAS Adsorption in Three-Dimensional Covalent Organic Frameworks.
Daniel D Mottern1, Andrei L Kolesnikov1,2, Gennady Y Gor1
1Otto H. York Department of Chemical and Materials Engineering, New Jersey Institute of Technology, Newark, New Jersey 07102, United States.
Summary
Nitrogen-based covalent organic frameworks (COFs) show promise for adsorbing per- and polyfluoroalkyl substances (PFAS). Material chemistry and pore structure significantly impact PFAS capture efficiency, with functionalization offering further improvements.
Area of Science:
- Materials Science
- Environmental Chemistry
- Computational Chemistry
Background:
- Growing concerns exist regarding per- and polyfluoroalkyl substances (PFAS) contamination in water sources.
- Novel porous materials are needed for effective and selective PFAS adsorption.
- Covalent organic frameworks (COFs) are a promising class of materials for environmental remediation.
Purpose of the Study:
- To investigate the influence of chemistry and structure of 3D COFs on perfluorooctanoic acid (PFOA) adsorption.
- To evaluate the impact of COF functionalization on PFAS adsorption.
- To identify optimal COF characteristics for enhanced PFAS removal from aqueous environments.
Main Methods:
- Monte Carlo (MC) simulations were employed to model PFOA adsorption onto various COF structures.
- The study analyzed the effects of COF porosity, nitrogen-based frameworks, and functional groups (-CF3, -NH2) on adsorption potential.
Main Results:
- Nitrogen-containing COFs demonstrated a high potential for PFAS adsorption.
- COF pore porosity significantly affected PFOA adsorption, with moderate porosity being more effective than high porosity.
- Functionalization with -CF3 and -NH2 groups enhanced PFOA-COF interactions but could reduce necessary porosity.
Conclusions:
- Nitrogen-based COFs are effective materials for PFAS adsorption.
- Optimizing COF porosity and functionalization is crucial for maximizing PFOA capture efficiency.
- Functionalized COFs with appropriate pore sizes offer a pathway for improved PFAS removal from water.
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