Cotton fiber hot spot in situ growth of Stöber particles

Textured cotton substrates are drawing interest as a new class of non-wetting and non-fouling materials. We investigated the effect of temperature, solvent and substrate presence on the in situ particle growth process for the production of self-cleaning, wash-resilient and air-permeable superhydrophobic and oleophobic cotton textiles. By comparing the size of particles grown in solution with those grown on cotton fibers, we show that the uniform solution growth follows a faster reaction rate. In general, the cotton surface favors the production of hierarchical structures that provide a liquid-repellent behavior, when combined with low surface free energy nanocoatings, such as an organically modified silane precursor or perfluoro ethers. In addition, the influence of an oil-based lubricant on the pinning effect was evaluated. On the basis of these findings, we present a low-cost method to manufacture nanostructured coatings to achieve optimal roughness and liquid repellence.