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Microfluidic-based Synthesis of Covalent Organic Frameworks COFs: A Tool for Continuous Production of COF Fibers and Direct Printing on a Surface

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Exceptional Iodine Capture in 2D Covalent Organic Frameworks.

Ping Wang¹, Qing Xu¹, Zhongping Li¹

¹Department of Chemistry, Faculty of Science, National University of Singapore, 3 Science Drive 3, Singapore, 117543, Singapore.

Advanced Materials (Deerfield Beach, Fla.)

|May 29, 2018

Summary

New porous materials capture radioactive iodine by utilizing 1D channels, demonstrating that pore volume, not binding sites, dictates uptake capacity for nuclear fission emissions.

Keywords:

1D channels covalent organic frameworks environmental protection molecular design radioactive pollutants

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Synthesis and Characterization of Functionalized Metal-organic Frameworks

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Published on: September 5, 2014

Area of Science:

Materials Science
Chemistry
Environmental Science

Background:

Porous materials have been developed for decades to capture iodine, a radioactive byproduct of nuclear fission.
Existing research often assumes that entangled pores and specific binding sites are crucial for effective iodine capture.

Purpose of the Study:

To challenge the conventional understanding of iodine capture mechanisms.
To explore the potential of one-dimensional (1D) channeled porous materials for iodine sequestration.

Main Methods:

Construction of two-dimensional (2D) covalent organic frameworks (COFs) designed without interpenetration or binding sites.
These COFs feature exclusively 1D open channels with varying geometries (hexagonal, tetragonal, trigonal) and sizes (micropores to mesopores).
Experimental verification of iodine accessibility and uptake across different channel structures.

Main Results:

The 1D channeled COFs demonstrated efficient iodine access and capture, irrespective of channel shape or size.
A new paradigm was established: pore volume is the primary determinant of iodine uptake capacity.
The absence of interpenetration and binding sites did not impede iodine capture, contradicting prior assumptions.

Conclusions:

One-dimensional channeled porous materials offer a novel and effective strategy for iodine capture.
Pore volume, rather than pore entanglement or specific binding sites, governs the capacity for iodine uptake.
These findings are critical for advancing the design of materials for treating radioactive iodine and other toxic vapors.