Bioinspired Design of Wetting and Anti-Wetting Surfaces via Thiol-ene Photopolymerization

Surface wettability is known to have a profound influence in both academic study and industrial application of materials. Superhydrophobic surfaces, with a static contact angle higher than 150° and a contact angle hysteresis lower than 10°, have received continued attention for their broad applications, such as self-cleaning, antifogging and frosting, and drag reduction. The continuous development of materials and approaches that used to create superhydrophobic surfaces has led to further exploration of coatings with other desirable properties such as superamphiphobicity, mechanical robustness and thermal stability. In this work, coatings with super wetting and super anti-wetting properties were designed and fabricated by tailoring the chemical composition and the morphology of the surface in an effort to expand the application and to improve the mechanical property of the coatings. In the first study, a superamphiphobic coating was prepared by spray deposition and followed up UV-polymerization of a hybrid organic-inorganic thiol-ene precursor. The combination of dual-scale roughness and low surface energy materials led to surfaces with strong water/ oil repellency and self-cleaning properties. In the second study, a superhydrophilic and superoleophobic membrane for oil/water separation applications was developed. The textured membrane morphology enhanced the hydrophilic and oleophobic properties of the surface. The efficiency of the superhydrophilic/superoleophobic membrane on oil/water separation was demonstrated by emulsion and dye contained emulsion separation studies. In the third study, a superhydrophobic surface was prepared with porogen leaching approach in an effort to reduce the loading level of NPs. The microphase separation and porogen leaching process resulted in microscale roughness. NPs migration from bulk to interphase led to the formation of nanoscale roughness. The combination of micro- and nano-scale feature provides the surface with superhydrophobicity with 50 wt.% reduced NPs loading level