3D-Printed Porous Polymer Monoliths for Tunable Pheromone Release

Polymerization-induced phase separation (PIPS) in scalable, low-cost LCD-based 3D printing enables the fabrication of inherently porous monoliths with tunable properties for volatile organic compound (VOC) release. Addressing the need for tunable semiochemical release in species-specific pest control, we present a proof-of-principle study on semiochemical emission using methacrylate-based 3D-printed monoliths loaded with verbenone as a model pheromone. By systematically varying porogens (turpentine oil vs cyclohexanol/1-decanol mixture), porogen-to-monomer ratio, and pheromone loading, distinct pore regimes ranging from submicrometer networks to micrometer-scale domains were generated in 3D porous cubes with an edge length of 5 mm. Morphological characterization by scanning electron microscopy and mercury intrusion porosimetry revealed that turpentine oil-based formulations exhibit larger pore domains than cyclohexanol/1-decanol-based analogs. Furthermore, headspace thermal desorption gas chromatography−mass spectrometry measurements of the 3D porous cubes demonstrated formulation-dependent verbenone emission, with turpentine-oil-based systems exhibiting higher emission intensities than cyclohexanol/1-decanol-based analogs. Overall, larger-pore formulations were generally associated with higher verbenone emission intensities; however, remaining porogens may also contribute to the observed behavior. The presented proof-of-principle results highlight the potential of combining PIPS with LCD-based 3D printing to fabricate porous polymer dispensers with tunable semiochemical emission characteristics, while quantitative control and long-term release remain a subject of future investigation. Thus, the findings provide a foundation for future studies on structure−emission relationships and the rational design of additively manufactured, bioinspired VOC release systems with potential applications in sustainable pest management and beyond.