Defect engineering of porous aromatic frameworks via end capping improves dioxane removal from water

Amorphous porous organic polymers show promise for energy -effi-cient adsorptive separations, but it is difficult to understand or improve their performance through intentional structural modifica-tion. Herein, we report the synthesis of porous aromatic frameworks (PAFs) with pore structures tailored by the incorporation of a mono-functionalized end-capping monomer that disrupts framework to-pology. Combining experimental characterization with molecular simulations, we show that this defect engineering strategy yields less densely crosslinked networks, which leads to pore collapse and the presence of unique adsorption sites. These defect -engi-neered PAFs exhibit enhanced removal of 1,4-dioxane, an impor-tant environmental pollutant, from water. Increasing the concentra-tion of end-capping monomers produces PAFs with narrower pore size distributions and improved 1,4-dioxane uptake. These results illustrate that defect engineering can effectively modulate polymer connectivity and porosity for applications in selective adsorptive separations. This technique avoids post-synthetic treatments and presents another approach to tailor amorphous polymeric adsor-bents.

Automated summary

This study reports the synthesis of porous aromatic frameworks (PAFs) with tailored pore structures by incorporating a mono-functionalized end-capping monomer. The defect engineering strategy leads to less densely crosslinked networks, resulting in pore collapse and the presence of unique adsorption sites. These defect-engineered PAFs exhibit improved removal of the environmental pollutant 1,4-dioxane from water, and increasing the concentration of end-capping monomers enhances their uptake.