Study on non-fluorinated superhydrophobic finishing of cotton fabric by silica hydrosol process

Silica hydrosol was prepared using methyltrimethoxysilane as precursor,ammonia liquor as catalyst in the presence of surfactant.Cotton with certain roughness was obtained by dip-coating the silica sol onto cotton surface,and then the cotton was immersed in the hydrophobic additive,ethanol digest,thus nano non-fluorinated superhydrophobic cotton fabrics could be obtained.The effects of ammonia liquor dosage and surfactant concentration on the hydrosol size and water repellency of fabrics were discussed.The influences of different structures and concentrations of the hydrophobic additive digest on the water-repellent property were also investigated.The results showed that the cotton surface roughness was greatly increased.After finishing,the water contact angle and water sliding angle of twill fabrics were 151.9° and 13°,respectively,which achieved the superhydrophobic effect.