(399a) Geometric Tailoring of Sorbent-Polymer Direct Air Capture Contactors Using Templated Phase Inversion

Cost-effective direct air capture (DAC) systems demand gas–solid contactors that combine efficient heat and mass transfer with low pressure drop. Triply periodic minimal surfaces (TPMS) exhibit superior transport properties over conventional geometries, but are difficult to fabricate using traditional methods like injection molding. Although non-solvent-induced phase separation (NIPS) has been explored to fabricate adsorbent-embedded structures, prior efforts have largely been limited to simple forms such as films and fibers.

Here, we introduce a templated phase inversion (TPI) technique that enables the formation of complex 3D architectures, including TPMS, by inducing NIPS within a dissolvable, water-soluble 3D-printed template. The method accommodates a wide range of adsorbents, including zeolites, silica, activated carbon, and metal–organic frameworks. Structural and morphological analyses using SEM, micro-CT, and nitrogen adsorption reveal hierarchical porosity and excellent geometric fidelity. TPMS DAC contactors incorporating poly(ethyleneimine)/silica adsorbents demonstrate CO₂ capture performances that rival or surpass those of other contactor geometries.