Cotton and polyester textiles finishing by sol-gel technique

Current efforts of research in the field of textile materials are focused on surface functionalization, by innovative and cost effective processes, to obtain products with new or improved properties and high added value that can widen their industrial application. The interest is focused on flame retardancy, UV-protection, resistance to weathering and microbiological attack, super-hydrophobicity and soil resistance. High finishing durability, high degree of homogeneity and superior chemical-physical properties coupled with a reduction of harmful compounds in textile finishing industry can be reached by the application of an hybrid inorganic-organic coating by sol-gel techniques[1-3]. The aim of this work is to confer a hydrophobic behaviour to cotton and polyester fabrics depositing a modified silica based film by sol-gel technique. Sol gel coatings were prepared mixing tetraetoxysilane-based sols with low amounts of hydrophobic additives (n-propyltrimethoxysilane, hexadecyltrimetoxysilane, 1H,1H,2H,2H–Fluorooctyltriethoxysilane). Moreover a LTP, low temperature plasma, pre-treatment was carried out on fabrics to improve the sol gel coating adhesion and fastness. Treated fabrics were characterized by SEM, FTIR and XPS while their wettability was evaluated by measuring the water contact angle. Best results were obtained with a TEOS/FOS combination (θ=148°) for polyester and TEOS/C16 for cotton (θ=140°). The enhanced coating adhesion, due to plasma surface activation, was confirmed by abrasion and washing fastness tests.