Silk fabrics modification by sol–gel method

Sol–gel is a very effective method to obtain high purity ceramic and hybrid coatings on a variety of substrates. Thanks to their unique structure and extremely reduced thicknesses, sol–gel coatings can remain adherent and transparent even on flexible substrates such as textiles. Hence, their versatile chemistry can be exploited to impart a variety of properties to fabrics. Here, we evaluated the potential of sol–gel coatings for the functionalization of silk fabrics, and in particular for the preparation of coatings able to simultaneously improve abrasion resistance and attain water-repellency. To this end, tetra-ethyl-ortho-silicate based (TEOS) hybrid coatings were prepared using different Si-alkoxides functionalized with either alkyl chains or fluorinated groups. Abrasion resistance, oil and water contact angle, mechanical properties and water vapor permeability were assessed on treated fabrics to identify the more promising formulations.