Functional Silane-Based Nanohybrid Materials for the Development of Hydrophobic and Water-Based Stain Resistant Cotton Fabrics Coatings

The textile-finishing industry, is one of the main sources of persistent organic pollutants in
water; in this regard, it is necessary to develop and employ new sustainable approaches for fabric
finishing and treatment. This research study shows the development of an efficient and eco-friendly
procedure to form highly hydrophobic surfaces on cotton fabrics using different modified silica sols.
In particular, the formation of highly hydrophobic surfaces on cotton fabrics was studied by using a
two-step treatment procedure, i.e., first applying a hybrid silica sol obtained by hydrolysis and subsequent
condensation of (3-Glycidyloxypropyl)trimethoxy silane with different alkyl(trialkoxy)silane
under acid conditions, and then applying hydrolyzed hexadecyltrimethoxysilane on the treated
fabrics to further improve the fabrics’ hydrophobicity. The treated cotton fabrics showed excellent
water repellency with a water contact angle above 150 under optimum treatment conditions. The
cooperative action of rough surface structure due to the silica sol nanoparticles and the low surface
energy caused by long-chain alkyl(trialkoxy)silane in the nanocomposite coating, combined with
the expected roughness on microscale due to the fabrics and fiber structure, provided the treated
cotton fabrics with excellent, almost super, hydrophobicity and water-based stain resistance in an
eco-sustainable way.