纳米TiO_(2)表面改性剂与分散溶剂的相容性研究

Study on the Compatibility Between Surface Modifiers of TiO2 Nanopar⁃ticles and Orginic Solvents

溶液共混法合成纳米复合材料可以控制纳米颗粒的粒度分布和表面性质,从而改善其在有机基体中的分散情况。纳米TiO_(2)因具有优异的光电性能在光学器件、光催化、传感器等领域得到广泛应用,其中纳米TiO_(2)在溶剂中的均匀分散,是溶液共混法制备高折射率纳米复合材料的重要前提。本研究采用3种不同碳官能团的硅烷偶联剂对纳米TiO_(2)表面进行改性,可以将其分散在极性不同的3种有机溶剂中,得到透明稳定的分散液。结果表明,纳米TiO_(2)经过3种硅烷偶联剂改性后,在庚烷、乙酸丁酯、正丁醇中的中位粒径(D50)分别为13.5、19.6、22.1 nm,分布系数(PDI)分别为0.038、0.231、0.171。动态光散射(DLS)测量和透射电子显微镜(TEM)观察结果表明,纳米TiO_(2)在庚烷、乙酸丁酯、正丁醇中均表现出良好的分散性。Turbiscan稳定性分析仪评估结果表明,具有相同纳米TiO_(2)质量分数的纳米TiO_(2)分散液具有不同的分散稳定性,说明相容性最好的硅烷偶联剂与分散溶剂是十六烷基三甲氧基硅烷与庚烷。纳米TiO_(2)在庚烷中分散得到的分散液具有高分散性和良好稳定性,其次为3-(甲基丙烯酰氧)丙基三甲氧基硅烷与乙酸丁酯。结果表明硅烷偶联剂碳官能团的性质影响了纳米颗粒与有机溶剂的相容性,这为制备高分散性和高稳定性的分散液提供了新思路。

Synthesis of high refractive index nanocomposite by solution blending method can control the particle size distribution and surface properties of nanoparticles,and improve the dispersion of nanoparticles in organic matrices.TiO_(2) nanoparticles are widely used in areas such as optical devices,sensors and photocatalysis because of their excellent photoelectric performance.The homogeneous dispersion of TiO_(2) nanoparticles in the organic solvent is an important prerequisite for preparing high refractive index nanocomposites by solution blending method.In this paper,three kinds of silane coupling agents(SCAs)with different carbon functionalities were used to modify the surface of TiO_(2) nanoparticles,which can be dispersed in three organic solvents with different polarities to obtain a transparent and stable dispersion.Results indicate that the median particle size(D50)of TiO_(2) nanoparticles in heptane,butyl acetate and 1-butanol are 13.5,19.6 and 22.1 nm,respectively,and the distribution coefficients(PDI)are 0.038,0.231 and 0.171,respectively.Dynamic laser scattering(DLS)measurements and transmission electron microscopical(TEM)observation indicate that the TiO_(2) nanoparticles are dispersed on a primary particle size level.Turbiscan stability analyzer analysis demonstrates that TiO_(2) dispersions with the same mass fraction of TiO_(2) nanoparticles have different dispersion stability,indicating that the best compatibility is hexadecyltrimethoxysilane and heptane,and the dispersion has high dispersibility and good stability,followed by 3-(methacryloyloxy)propyltrimethylsilane with butyl acetate.This study indicates that the properties of the carbon functionalities of the SCAs are vital to the dispersion state of TiO_(2) nanoparticles in organic solvents,and provides a new idea for the preparation of dispersion with high dispersibility and stability.