3D‐Printed Porous Organic Cages for Gas Filtration: Fabrication and Flow Simulations

Abstract

AbstractPorous organic cages (POCs) are a class of emerging porous materials with high porosity and selectivity for gas adsorption and separation. As a representative of first‐generation POCs, the cage molecule CC3, has huge potential for separating noble gases and volatile organic compounds (VOCs). 3D printing CC3 using direct ink writing (DIW) offers significant advantages to build complex structures. Through rational design, formulations that are both printable and functional are achieved. Optimised formulations have the elasto‐visco‐plastic behavior required while retaining the functional properties of the cages. The characterization of printed parts evidence that the CC3 structure and adsorption capacity are well preserved. BET surface areas vary with CC3 concentration and can reach up to ≈249 m2 g−1 for 70 wt% CC3. However, high CC3 content leads to a decrease in shrinkage, higher porosity, and low compressive strength ≈0.7 MPa. Computational fluid dynamics (CFD) is used to investigate the gas flow behavior through grid‐type structures with tailored geometric parameters. The results reveal that changing the offset distance and porosity manipulates the flow path, velocity distribution, and pressure drop. This work provides a pathway to design and fabricate structures with multi‐scale porosity that can be widely used for other functional materials and applications.