Double layer approach to create durable superhydrophobicity on cotton fabric using nano silica and auxiliary non fluorinated materials

• Published in: Applied surface science 2016-01, Vol.360, p.777-788
• Main Authors: Manatunga, Danushika Charyangi, de Silva, Rohini M., de Silva, K.M. Nalin
• Format: Article
• Language: English
• Subjects: Contact angle; Cotton; Cotton fabrics; Double layer; Fabrics; Hydrophobization agents; Scanning electron microscopy; Silanes; Silica nanoparticles; Silicon dioxide; Soil (material); Superhydrophobicity
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2015.11.068

⿢Superhydrophobicity using nonfluorinated agents on cotton roughened with nanosilica.⿢Sol⿿gel method to hydrophobize with HDTMS, SA, OTES, and HDTMS/SA HDTMS/OTES hybrids.⿢WCA of 150° or greater with the treatment.⿢Increased hydrophobicity and soil repellency obtained when a hybrid mixture is used.⿢Combinational treatment is effective when compared with the fluorosilane treatment. Creation of differential superhydrophobicity by applying different non-fluorinated hydrophobization agents on a cotton fabric roughened with silica nanoparticles was studied. Cotton fabric surface has been functionalized with silica nanoparticles and further hydrophobized with different hydrophobic agents such as hexadecyltrimethoxy silane (HDTMS), stearic acid (SA), triethoxyoctyl silane (OTES) and hybrid mixtures of HDTMS/SA and HDTMS/OTES. The cotton fabrics before and after the treatment were characterized using scanning electron microscopy (SEM), atomic force microscopy (AFM) and thermogravimetric analysis (TGA). The wetting behavior of cotton samples was investigated by water contact angle (WCA) measurement, water uptake, water repellency and soil repellency testing. The treated fabrics exhibited excellent water repellency and high water contact angles (WCA). When the mixture of two hydrophobization agents such as HDTMS/OTES and HDTMS/SA is used, the water contact angle has increased (145°⿿160°) compared to systems containing HDTMS, OTES, SA alone (130°⿿140°). It was also noted that this fabricated double layer (silica+hydrophobization agent) was robust even after applying harsh washing conditions and there is an excellent anti-soiling effect observed over different stains. Therefore superhydrophobic cotton surfaces with high WCA and soil repellency could be obtained with silica and mixture of hydrophobization agents which are cost effective and environmentally friendly when compared with the fluorosilane treatment.