Fabrication of highly transparent rigid polyurethane with superhydrophobic and slippery liquid-infused porous surfaces

Transparent rigid polymer materials are widely used in displays, optical sensors, and medical devices because of their excellent optical properties and durability. However, conventional transparent rigid polymer surfaces are not superhydrophobic (SHPo) and do not possess the characteristics of slippery liquid-infused porous surface (SLIPS), which limits their application. In this study, a novel surface processing method capable of imparting both SHPo and SLIPS properties to transparent rigid polyurethane (PU) was developed and characterized. Specifically, a SHPo structure was fabricated on aluminum via etching and functionalization and then replicated onto rigid, transparent PU through a polydimethylsiloxane mold. Moreover, a SLIPS was formed by infusing the SHPo PU with a lubricant. The transparency of SLIPS can be controlled through the difference in refractive index between the PU substrate and lubricant, and a SLIPS with high optical transmittance was successfully prepared using silicone oil. SLIPS fabricated using this new approach can simultaneously satisfy the durability and transparency requirements for various industrial applications of functional surfaces.