Synthesis and characterization of a novel fluorine-free superhydrophobic finishing agent

SiO2 gel dispersion was synthesized via acid-base two-step process using methyltrimethoxysilane as precursor,oxalic acid and ammonia as catalyst. The prepared dispersion was applied onto cotton fabric.The treated cotton fabric was characterized by contact angle measurement,FT-IR,TEM and BET surface area analysis. The results showed that three dimensional network composed of silica nanoparticles and the existence of abundant methyl groups render the cotton fabric superhydrophobicity. The static contact angle of the treated cotton fabric was 161° while the sliding angle was less than 5°.