Rapid, Template‐Less Patterning of Polymeric Interfaces for Controlled Wettability via in Situ Heterogeneous Photopolymerizations

Abstract

AbstractTuning macroscopic behavior between a synthetic surface and the surrounding environment requires precise engineering of micro‐ and nanoscale features at the interface. As one example, the geometry and spacing of topographical structures can be manipulated to modify interfacial interactions with water. If optimized correctly, topographical features can impart macroscopic wetting behavior that goes well beyond what is expected from the chemistry of the surface materials, such as strong hydrophobicity from intrinsically hydrophilic materials. However, developed techniques such as templating or nano‐lithography require significant processing times and are often ill‐suited for in situ applications. This work shows that polymeric interfaces with regular, ordered topographical features can be generated using a rapid in situ photopolymerization technique that requires no templating nor additional processing to generate or manipulate surface features. Maximizing the local differential in polymerization‐induced shrinkage between heterogeneous domains results in the formation of robust 3D surface features. Furthermore, the spacing and density of these features can be optimized through the phase separation process, yielding surfaces with variable wetting (θw ≈ 90–130°). These results demonstrate that template‐ and mask‐less surface patterning is possible with rapid polymerization techniques and that it can be easily manipulated to vary surface wetting behavior.