Surface Modification with Silicon Sol on Cotton Fabrics for Water-Repellent Finishing

The cotton fabrics were surface modified for water repellent finishing with silicon sol, which was prepared with the tetraethoxysilane(TEOS) and solvent ethanol, catalyzer HCl, water and modified with additives, such as Methyltriethoxysilane(MTEOS),Octyltriethoxysilane(OTEOS) and Hexadec-ltrimethoxysilane(HTEOS). As a result, acceptable water repellence could only be achieved via the addition of longer chain length additives such as OTEOS, HTEOS, while the use of additives containing a shorter alkyl chain length such as MTES led to insufficient water repellence. The factors which influence contact angles were examined. Excellent water repellent properties could be achieved on the cotton fabrics treated with the silica sols by twice dip and pad and cured at 160°. The silica sol preparation preference conditions were with TEOS: H₂O: EtOH=1: 5: 8 (mol) by stirring for 6 hours at 65°C which was added with HTEOS. The water repellence contact angle was able to be reached around 140° and the hydrostatic pressure was 46cm.