纳米SiO_2的表面改性

Surface modification of nano-SiO_2

分别用吐温-80、油酸、十二烷基苯磺酸钠、硅烷偶联3-氨丙基三乙氧基硅烷(KH550)和硅烷偶联剂γ-(甲基丙烯酰氧)丙基三甲氧基硅烷(KH570)处理纳米二氧化硅,用沉降体积和亲油化度来对比改性效果,结果表明KH570改性效果最好,其最佳工艺条件为:KH570用量为8%,反应温度为70℃,反应时间为2 h,反应pH为5.5。对KH570改性前后的纳米粉体进行了红外光谱分析、热重分析、紫外-可见光谱分析、扫描电镜分析等表征。结果表明,硅烷偶联剂与纳米二氧化硅之间形成了化学结合,改性后的纳米SiO_2分散性提高,从而更好地应用于聚合物材料中。

The surface of nano-SiOzparticles was modified with tween-80 ,oleic acid ,sodium dodecyl ben- zene sulfonic acid and silane coupling agent 3-aminopropyhriethoxysilane （KH550） and y-methacrylo- xypropyltrimethoxysilane （KH570）. Sedimentation volume and lipophilic degree were used to compare the modification effect. The optimal modification conditions were as follows： KH570 content was 8% （mass fraction） based on SiO2, reaction temperature was 70 %, reaction time was 2 h and reaction pH was 5.5. The modified and unmodified SiO2 were characterized by ultraviolet visible spectrometer （UV-Vis）, Fou- rier transform infrared spectrometer （ FTIR）, thermogravimetric analysis and transmission electron micros- copy （TEM）. The results showed that KH570 attached to the surface of nano-sized SiO2 chemically. The dispersion property of the modified nano-SiOEwas improved. So it is better used in polymer materials.