Direct Ink Writing 3D Printing of Anisotropic Superhydrophobic/Superelastic Porous Silicone Rubber for Recyclable Dichloromethane Absorption

Special wettability on biological surfaces generally arises from the synergy between hierarchical microstructures and surface chemistry, providing inspiration for biomimetic superhydrophobic materials. However, conventional fabrication strategies often involve complex procedures or expensive molds, limiting the precise construction of ordered microstructures. Herein, direct ink writing (DIW) 3D printing was used to fabricate polydimethylsiloxane (PDMS)-based porous silicone rubber with integrated anisotropic surface wettability (ASW), superhydrophobicity, superelasticity, and dichloromethane (DCM) absorption performance. By regulating printing speed, pneumatic pressure, and nozzle angle, porous silicone rubber with well-defined anisotropic microstructures was constructed. The DIW-printed porous silicone rubber exhibited pronounced ASW and superhydrophobicity. The material maintained structural integrity under compressive strain and rapidly recovered its original shape after unloading. After 1000 cycles of tensile and compressive loading, the tensile strength decreased while the compressive strength showed no significant degradation, demonstrating excellent superelasticity and low energy dissipation. The DIW sample showed faster DCM uptake within 30 min, compared with conventional hot-pressed PDMS materials, whereas the equilibrium adsorption capacities of both materials after one day of exposure were comparable. Meanwhile, the DIW sample exhibited excellent stability during cyclic DCM absorption. In addition, the material maintained stable DCM absorption performance under contaminated conditions and at different temperatures. This study provides a new strategy for fabricating multifunctional intelligent porous elastomers via 3D printing, and the prepared material shows possible applications in DCM–water separation and potential applications in waterproof materials and porous biomedical materials.