Formation of Highly Hydrophobic Surfaces on Cotton and Polyester Fabrics Using Silica Sol Nanoparticles and Nonfluorinated Alkylsilane

Water and soil repellency is one of the most desirable properties for textile fabrics. A surface with a water contact angle higher than 150° is considered to be a practically nonwettable superhydrophobic surface. In this research, we studied the formation of highly hydrophobic surfaces on cotton and polyester fabrics using silica sol formed by hydrolysis and subsequent condensation of tetraethoxysilane under alkaline conditions followed by hydrophobization using hydrolyzed hexadecyltrimethoxysilane (HDTMS). The textile fabrics thus treated showed excellent water repellency with a water contact angle as high as 155° on cotton and 143° on polyester. The high hydrophobicity of the treated fabrics is due to the presence of hydrophobic HDTMS as well as the increase in roughness by silica sol on the surfaces of the treated fabrics. The morphology of the cotton and polyester fabrics were characterized by scanning electron microscopy. We also found that the treated cotton and polyester are resistant to hydrolysis of multiple washing cycles.