Preparation Of Super-Hydrophilic And Antistatic Polyamide Fabric By Sol-Gel Method With Si_O2/TiO₂Composite Hydrosol

As an environment-friendly method, sol-gel technique in textile finishing application has become one of the hot researches in current textile science. The super-hydrophobic finishing by sol-gel technique is most studied. However, there has rare research on super-hydrophilic finishing of synthetic fiber. The feasibility of super-hydrophilic and antistatic surface with SiO2/TiO2composite hydrosol by sol-gel method with tetraburylorthotitanate (TBOT) and tetraethylorthosilicate (TEOS) as precursor was investigated in this study.The composite hydrosol was first made by one-step method and two-step method respectively. In order to make hydrophilic and antistatic agent SiO2/TiO2composite hydrosol be applied on all kinds of polyamide fabric, the nylon fabric (166g/m2) and nylon taffeta210T were chosen as matrix.Super-hydrophilic and antistatic nylon fabric was successfully prepared by dip-coat-dry-baking processing with the SiO2/TiO2composite hydrosol. Hydrophilic and antistatic properties of the treated fabric were determined by water contact angle, peak voltage, half-life time and capillary effect measurement. The influence of the preparation methods of composite hydrosol, the composite hydrosol of Si%/(Si%+Ti%) ratio, the concentration of the composite hydrosol on hydrophilic and antistatic properties of the treated fabric were discussed. The super-hydrophilic durability of samples was also researched by comparing water contact angle of the treated polyamide fabric before and after washing.The experimental results showed that the hydrophilicity and antistatic property of the polyamide fabric treated by SiO2/TiO2composite hydrosol were improved. The hydrophilic property of the treated fabric prepared by two-step method was far better than that by one-step method. With increase of Si%/(Si%+Ti%) ratio of the composite hydrosol, the hydrophilic and antistatic property of the treated fabric first increased and then decreased. When the Si%/(Si%+Ti%) ratio were0.89and0.91, the treated fabric showed super-hydrophilicity. The hydrophilicity of the treated fabric decreased with decrease of the concentration of Si%+Ti%in the composite hydrosol. The results showed that the polyamide fabric treated with sol (Si%+Ti%)=0.25%, Si%/(Si%+Ti%)=0.80for nylon fabric (Si%/(Si%+Ti%)=0.89for nylon taffeta210T) and cured at130℃for5min showed excellent hydrophilicity and antistatic property.In order to study the surface morphology change of the fabric before and after finishing, FESEM was used to discuss super-hydrophilic mechanism of SiO2/TiO2composite hydrosol. It was found that the fibrous surface was covered with a layer of smooth and uniform SiO2/TiO2gel after the treatment.As a whole, energy was saved and cost was reduced by using cheap tetrabutylorthotitanate (TBOT) and tetraethylorthosilicate (TEOS) as precursor, and water in place of anhydrous ethanol in course of (Si+Ti) sol. Moreover, this topic did not use any organic solvent besides a small amount of glacial acetic acid as catalyst. Above all, the preparation process was simple, and the finished fabric has both super-hydrophilicity and excellent antistatic performance. It would enlarge the application of sol-gel technology in the textiles and industrialize in the future.