A novel sol-gel multi-layer approach for cotton fabric finishing by tetraethoxysilane precursor

• Published in: Surface & coatings technology 2013-11, Vol.235, p.192-203
• Main Authors: Colleoni, C., Donelli, I., Freddi, G., Guido, E., Migani, V., Rosace, G.
• Format: Article
• Language: English
• Subjects: Applied sciences; Catalysts; Coatings; Cotton; Cotton fabric; Cross-disciplinary physics: materials science; rheology; Dibutyltindiacetate; Exact sciences and technology; Fabrics; Finishing; Materials science; Mechanical properties; Metals. Metallurgy; Multi-layer; Physics; Precursors; Production techniques; Sol gel process; Sol-gel; Surface treatment; Surface treatments; Tetraethoxysilane; Textiles
• ISSN: 0257-8972; 1879-3347
• DOI: 10.1016/j.surfcoat.2013.07.033

The way of producing functional textile finishings by the sol-gel process using a multistep approach, consisting of consecutive depositions of sol layers on cotton fabric, for obtaining architectures with a different number of layers (namely, 1, 3 or 6 layers) is discussed. To this aim, tetraethoxysilane (TEOS) has been used as a precursor and the role of such architectures has been deeply investigated and correlated with the sol concentration and with the presence of the condensation catalyst DBTA (Dibutyltindiacetate). The multi-layer coatings were applied by padding using sols containing appropriate molar ratios of the precursor, anhydrous ethanol, catalyst and hydrochloric acid. The effects of the catalyst during the alkoxide reaction and the silica amount applied by sol-gel treatment on the thermo-oxidative behavior of the treated fabrics were deeply studied. FT-IR ATR spectroscopy, SEM analysis, thermal and thermo-oxidative stability, washing fastness, flammability and mechanical properties of the sol-gel treated cotton fabrics have been also investigated. The results obtained should be interpreted according to the properties investigated. The higher the concentration and the number of layers of the inorganic matrix, the higher the heat protection of textile samples. However, the resulting coating was so rigid that it modified the mechanical properties and particularly it decreased the wear resistance according to Martindale test. To improve the mechanical properties the best results were obtained by modulating a lower concentration of the matrix using a layered approach. In all cases, high adhesion of the coating to the textile fabrics was observed. •The multi-layer approach allowed a high flexibility in getting the required performances.•Heat protection increases with the concentration and the number of layers of TEOS.•0.3M TEOS gives the best thermal stability and good washing fastness performances.•The coating modified the mechanical properties and wear resistance.•DBTA catalyst seems to improve both washing fastness and abrasion resistance.