关键词: 自发单层分散, 临界分散温度, 单层分散阈值, 有机物单层分散

Abstract:

XRD and FT-IR methods were applied to the studies of organic monolayer dispersion systems. Naphthalene, borneol, benzoic acid, salicylic acid, phthalic acid and tartaric acid were mixed with γ-Al2O3 and SiO2 separately. The results showed that the organic compounds can also disperse spontaneously onto the surfaces of different oxide-supports to become high dispersion states like the behavior of inorganic salts and oxides. The organic substances studied are more ready to disperse with 1ess carboxyl or hydroxyl groups on their aromatic nucleus, suggesting the migration on the surface of the support is rate-determining during the dispersion. This point of view is supported by the result of IR spectroscopy. The IR spectra of dispersed systems suggest that the carboxy1 may react with the surface hydroxyl groups of the support to form salt-like structures on the surface.

Key words: Spontaneous monolayer dispersion, The critical dispersion temperature, Dispersion threshold, Monolayer dispersion of organic compounds