A Simple Drop-and-Dry Approach to Grass-Like Multifunctional Nanocoating on Flexible Cotton Fabrics Using In Situ-Generated Coating Solution Comprising Titanium-Oxo Clusters and Silver Nanoparticles.

Multifunctional nanocoatings have been of central importance in various technological fields, yet their fabrication, especially on flexible substrates, still remains a persistent challenge to date. We herein demonstrate a mild single-step drop-and-dry approach to the in situ growth of hierarchical grass-like nanostructures on flexible cotton fabrics. A precursor solution comprising titanium-oxo clusters [Ti18MnO30(OEt)20(MnPhen)3] (Phen = 1,10-phenanthroline) and AgNO3 is employed wherein Ag+ cations are in situ-reduced to silver nanoparticles (AgNPs). Drop-casting onto cotton fabrics under mild conditions induces the in situ growth of the heterogeneous grass-like assembly, and each constituent nanofibrous 'grass leaf' incorporates AgNPs both on the surface and embedded in the interior. The hierarchical morphology and heterogeneous composition of these grass-like nanostructures impart the coated cotton fabrics with enhanced antibacterial properties, robust hydrophobicity, and UV-blocking capability, which are features desired in textile materials but lacking in natural cotton.