Formation of oil-soluble uniform anatase titania nanoparticles and their characterization

Uniform oil-soluble anatase nanoparticles (NPs) were obtained by a novel oil–water interface method, using tetra-n-butyl titanate (TnBT) of 0.25 mol/L and dodecylamine (DDA) of 0.10–0.60 mol/L in cyclohexane as the oil phase, and diluted NaOH or HClO4 solution as the water phase. The particle size was tuned by adjusting various reaction parameters, with the smaller grain size occurring at lower pH of the water phase, or relatively higher temperature (160 °C), shorter reaction time, and relatively higher DDA concentration. Additionally, the aspect ratio of the titania NPs increased with the decline of preparation temperature probably due to the anisotropic growth. More importantly, the formation process of the uniform oil-soluble titania NPs by this method was proposed based on the above results and the previous outstanding work for synthesis of monodispersed inorganic NPs. This work will conduce to the application of oil-soluble titania and the formation of other monodispersed inorganic NPs.

This scheme suggests the formation of oil-soluble titania NPs. Four various processes are introduced as L-p-F, L-p-S, H-p-F and H-p-S. By these processes, the oil-soluble titania NPs with different size and size-distribution are obtained. Titania NPs with the narrowest size-distribution are formed by H-p-F process.Figure optionsDownload as PowerPoint slideHighlights
► Oil-soluble uniform titania NPs were synthesized by the oil–water interface method.
► DDA adsorption plays the decisive role on the products dispersed in the oil phase.
► The formation process of titania by the oil–water interface method was proposed.