Development of self-cleaning superhydrophobic cotton fabric through silica/PDMS composite coating

The lotus effect informs that self-cleaning superhydrophobic surfaces can be obtained by creating rough surface structures and modifying them with chemicals that have low surface energy. Herein, the composite of hydrophobic silica nanoparticles (SNPs) and polydimethylsiloxane (PDMS) was deposited on cotton fabric by multiple dip cycles. At optimal condition, the agglomerated SNPs in PDMS produces a hierarchical rough surface, as a result the coated cotton fabric has revealed a water contact angle (WCA) of 158.41 +/- 1.58 degrees and 4 degrees of sliding angle. Due to negligible water adhesion to a superhydrophobic surface, coated cotton fabric reveals excellent self-cleaning behavior, which was tested by dust particles, muddy water and tea droplets. Furthermore, coated cotton fabric sustains superhydrophobicity over the mechanical robustness tests including adhesive tape peeling test, sandpaper abrasion test, and ultrasonication. Therefore, such an approach may be applicable in textile industries for self-cleaning purposes.