Fabrication of mechanically robust superhydrophobic surfaces based on silica micro-nanoparticles and polydimethylsiloxane

Surfaces with superhydrophobicity are important in a number of biological and industrial processes. Hierarchical film based on polydimethylsiloxane (PDMS) and SiO2 with a water contact angle of 155° and sliding angle of 6° was prepared by a facile drop-coating method. Surface modification of SiO2 spheres was found to improve particle dispersion and increase their compatibility with PDMS, which eventually affected the stability of the hierarchical structure. Different curing temperatures were studied for enhancing the hydrophobicity of the hierarchical structure. We examined the mechanical robustness of the superhydrophobic surface by using a shear test, and found that the hierarchical PDMS-based SiO2 films retained superhydrophobicity after 48 KPa mechanical shears.

Research highlights
► Mechanically robustness superhydrophobic surface was obtained by a simplely drop-coating process.
► We firstly induced the mechanical shear to evaluate the stable superhydrophobic surface.
► Surface modification of SiO2 spheres was found to increase their compatibility with PDMS.