氟改性硅溶胶的制备及性能

Preparation and properties of fluorine-modified silica sol

[目的]具有特殊润湿性的透明疏水材料在自清洁、金属防腐、微流体运输、防结冰、油水分离等领域具有广阔的应用前景。[方法]以正硅酸乙酯(TEOS)作为前驱体,十七氟硅烷偶联剂(FAS)和环氧硅烷偶联剂(KH560)为改性剂,采用两步法制备了氟改性硅溶胶,并将其涂覆在载玻片和聚丙烯(PP)纤维织物表面,制成了疏水材料。采用接触角测量仪、傅里叶变换红外光谱仪和扫描电镜对其进行表征,考察了改性剂的用量、水解时乙醇的比例及稀释倍数对材料疏水性能的影响。[结果]在乙醇与水的质量比为3∶2,偶联剂总用量为3%(质量分数),FAS与KH560的质量比为1∶1的条件下制备的硅溶胶稀释10倍后可以在载玻片和织物表面形成致密的涂层,它们对水的接触角分别达到了112°和153°,且具有优异的自清洁性能。[结论]通过溶胶-凝胶法,利用TEOS与FAS共水解的方式,可以获得性能优异的疏水材料。

[Introduction]Transparent and hydrophobic materials with special wettability have wide application prospects in self-cleaning,metal anticorrosion,microfluidic transport,anti-icing,and oil-water separation.[Method]A fluorine-modified silica sol was prepared by two-step method with tetraethyl orthosilicate(TEOS)as precursor and heptafluorosilane coupling agent(FAS)and epoxysilane coupling agent(KH560)as modifiers.Two hydrophobic materials were then prepared by coating the glass slice and polypropylene(PP)fabric with the fluorine-modified silica sol.The silica sol and hydrophobic materials were characterized by using contact angle goniometer,Fourier-transform infrared spectroscope,and scanning electron microscope.The effects of the dosage of modifiers,the proportion of ethanol during hydrolysis,and the dilution ratio on the hydrophobic properties of the materials were studied.[Result]The fluorine-modified silica sol prepared with 3%of total coupling agents at a FAS-to-KH560 mass ratio of 1:1 by hydrolysis in solution with a mass ratio of ethanol to water of 3:2 and 10-fold dilution could form a compact coating on glass and fabric,endowing their surfaces with a water contact angle of 112°and 153°,respectively.Moreover,the two hydrophobic materials possessed excellent self-cleaning performance.[Conclusion]The hydrophobic materials with excellent properties can be obtained via sol-gel method by co-hydrolysis of TEOS and FAS.