화학공학소재연구정보센터
Langmuir, Vol.25, No.21, 12713-12720, 2009
Organic Solvent-Dispersed TiO2 Nanoparticle Characterization
Anatase titanium dioxide nanoparticles are derivatized with the polymerizable reagent (3-methacryloxypropyl)-trimethoxysilane to provide dispersions in organic solvent, The titania core particles are characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD). The organic component structures and thickness are elucidated using nuclear magnetic resonance (NMR), quasielastic light scattering (QELS), and size-exclusion chromatography (SEC). Thin, high-refractive-index coatings prepared from the organic dispersions are characterized by atomic force microscopy (AFM). The combination of microscopies, spectroscopy, light scattering, and separation techniques provides unique information on the structure, thickness, morphology, and size distributions of the surface-treated nanoparticles that is difficult to obtain by any single technique. The findings indicate titania platelets with a modal diameter of 9.8 nm and a thickness of approximately 1.5 nm. The particles are coated with a 1.5-1.9 nm thick organic ligand layer, and a substantial population of 2 nm siloxane oligomers is detected, The analytical methodology presented may also be useful for characterizing other anisotropic organic-inorganic nanoparticles and their dispersions.