Resumo

CORNEJO-MONROY, D. et al. Nanoesferas monodispersas de SiO₂: síntesis controlada y caracterización. Superf. vacío [online]. 2009, vol.22, n.3, pp.44-48. ISSN 1665-3521.

In this work, we evaluated the effect of variation in concentration and the successive or simultaneously addition of reactants on size, dispersion and morphology of SiO₂ nanospheres. Particles with different diameters were obtained by hydrolysis and condensation of TEOS in an ammonium hydroxide and alcohol solution. Simultaneously or successive addition of TEOS to different ammonium hydroxide solutions varying in concentration produced SiO₂ nanoparticles with sizes ranging between 22 and 230 nm. Bigger and mono-dispersed particles were obtained at higher concentrations of ammonium hydroxide. However, when lower concentrations of ammonium hydroxide were employed, the particle size diminished but dispersion increased. The quantity of prepared sample had not a significant effect in structural properties of particles. The subsequent addition of TEOS produced SiO₂ surfaces with increased roughness. Transmission electron microscopy was used to monitor the formation, size and morphology of SiO2 nanospheres. The samples was characterized with FT-IR spectroscopy we find that the nanospheres have a composition of SiO₂ regardless of the experimental conditions used growth.

Palavras-chave : SiO₂; Nanospheres; Colloidal dispersion; Nanoparticles; Morphological properties.

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