纳米SiO_2的改性及其分散性研究

The Modification and Dispersion Study of Nano Silica

未经改性的纳米SiO2,由于其表面强烈的亲水性,使其不能均匀地分散在有机介质中,限制了纳米SiO2的进一步应用,因此必须对其改性.为此,该文用甲苯-2,4-二异氰酸酯(TDI)和低级醇对其进行改性,用TG、IR、透水速度、活化指数等手段对其进行了表征,并考察了其在不同介质中的分散稳定性.结果表明:改性纳米SiO2的表面结构发生了有机化转变,表现为较强的疏水亲油性,其在有机介质中的分散稳定性得到显著改善.

It is well known that untreated nano silica can＇t be well dispersed in organic media duo to its＇ strong hydrophilicity. Thus, it＇s widely use as nano particle is greatly limited. Therefore, modification has to be carried out. In this paper, TDI and lower alcohols were selected as modifying agent of nano silica, and modified nano silica were characterized via different means, such as TG, IR, permeable velocity, and activation coefficient. Meanwhile, its dispersability and stability in different media were studied. The results showed that, after modification, the surface structure of nano silica had been transformed organically, which cause to a hydrophobic property. Correspondingly, the dispersibility and stability of nano silica in organic media was significantly improved.