Superhydrophobic self-similar nonwoven-titanate nanostructured materials

Abstract Hypothesis: Self-similarity is a scale-invariant irregularity that can assist in designing a robust superhydrophobic material. A combinatorial design strategy involving self-similarity and dual-length scale can be employed to create a new library of a doubly re-entrant, disordered, and porous network of superhydrophobic materials. Asymmetric wettability can be engineered in nonwoven materials by rendering them with superhydrophobic characteristics on one side. Experiments: A facile, scalable, and inexpensive spray-coating technique was used to decorate the weakly hydrophobic stearate-treated titanate nanowires (TiONWs) over the self-similar nonwoven material. Laser scanning confocal microscopy was employed to image the impalement dynamics in three dimensions. With the aid of X-ray microcomputed tomography analysis, the 3D nonwoven structural parameters were obtained and analyzed. The underwater superhydrophobic behavior of the prepared specimens was observed and analyzed. Findings: A classic 'lotus effect' has been successfully endowed in self-similar nonwoven-titanate nanostructured materials (SS-Ti-NMs) from a nonwoven material that housed the air pockets in bulk and water repellent TiONWs on the surface. The finer fiber-based SS-Ti-NMs exhibited lower roll-off angles and a thin water layer on its surface. An asymmetric wettability and the unusual display of underwater superhydrophobic behavior of SS-Ti-NMs have been uncovered.