Preparation of TiO2 nanoparticles surface-modified by both carboxylic acid and amine: Dispersibility and stabilization in organic solvents

TiO2 nanoparticles, which were dispersed at the high concentration (more than 10%, w/v) in the organic solvent, were successfully prepared by a two-step modification using both propionic acid and n-hexylamine. It was well dispersed, comparing with TiO2 nanoparticles surface-modified by only hexanoic acid or n-hexylamine. The as-prepared sample were characterized using powder X-ray diffraction (XRD), Fourier transform infrared spectra (FTIR), UV–visible spectroscopy (UV–vis), transmission electron microscopy (TEM), thermogravimetric–differential thermal analyses (TG–DTA) and proton nuclear magnetic resonance (1H NMR).