Fabrication of superhydrophobic, antibacterial, and ultraviolet-blocking cotton fabric

Inspired by the superhydrophobic behavior of lotus leaf, a simple coating method was developed which could facilitate bionic creation of superhydrophobic surfaces on cotton textiles with a new functional properties. Silver nanoparticles (AgNPs) with a high deposition density were formed on the surface of cotton fabric through an alkali pre-activation followed by in situ reduction of silver nitrate. The Ag-coated fabric was then reacted with octyltriethoxysilane (OTES) to form a low surface energy layer on the fiber surface. The fabrics were characterized by ultraviolet-visible reflectance spectrophotometry, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy, and X-ray diffractometry. Hydrophobicity properties were assessed by contact angle (CA) goniometry and shedding angle (SHA) technique. Antibacterial activity was measured against Staphylococcus aureus and Escherichia coli bacteria, and UV-blocking ability was measured using the AATCC method. SEM images showed the formation of AgNPs which were distributed uniformly on the fibers' surface with a high coating density. Superhydrophobicity property of the treated fabric was confirmed with the CA of 156 degrees and SHA of 8 degrees. High antibacterial activity was observed without the reduction of inhibition size after coating with the OTES. The fabric also showed excellent UV-blocking with the ultraviolet protection factor of 266.01.