Sol-gel based coatings for the protection of cultural heritage textiles

In this paper, the procedure for the development of sol-gel silica coatings for the protection of cultural heritage textiles, using a multistep approach, is described. With this aim, Tetraethoxysilane precursor was used at two different concentrations to realize coatings onto textile samples, using Dibutyltindiacetate as polycondensation catalyst for sol-gel reactions. The relationship between the presence of the catalyst, the number of coating layers deposited on cotton fabrics, and the influence of such architecture on several properties of treated textiles, were investigated. In particular, the chemical structure of thin films and their morphology were studied by infrared spectroscopy and scanning electron microscopy, respectively. The thermo-oxidative properties and the abrasion resistance of sol-gel treated cotton fabrics were studied, as well as the durability of the coatings after different washing cycles. Both silica coatings provided high adhesion onto cotton textiles, while the higher silica concentration resulted in higher thermal stability and washing fastness of treated fabrics. An enhancement in the washing fastness and abrasion resistance for the two different concentrations of precursor in the presence of the catalyst was also observed. All experimental findings demonstrated the efficiency of sol-gel based materials specifically tailored to the protection and preservation of cultural heritage textiles.