Macro-Textured Fabric Reduces Water Droplet Impact Contact Time

Reducing fabric wetting by minimizing the contact time of impacting droplets is beneficial in many textile applications, such as rainwear and personal protective equipment. Macro-texturing of rigid superhydrophobic surfaces is a technique to reduce droplet impact contact time that has not previously been applied to textiles. This study examines utilizing inherently macro-textured superhydrophobic fabrics to reduce the contact time of impacting water droplets, adjusting the fabric topography through stretching and gathering to optimize the macro-texture. Fabrics were finished with either a commercial superhydrophobic finish or a developed superhydrophobic formulation utilizing fumed silica nanoparticles and poly(dimethylsiloxane) (PDMS) brushes. Various droplet splitting impact behaviors were observed and depended on the impact site and geometry of the macro-textured fabric. A 2:1 gathering ratio on woven seersucker fabric provided a 52% decrease from the theoretical minimum contact time for droplet impact on a ridge site. Rigid 3D-printed superhydrophobic surfaces that mimicked the fabric topography provide a useful analogue to the fabric surface for fine-tuning fabric designs.