Study on preparation and fluorescence characteristic of the (Alqx)/Al2O3 nano colloids

Alumina 8-hydroxyquinoline complexes (Alqx)/Al2O3 nano colloids have been successfully prepared by focused, pulsed laser ablation at the interface of solid Al2O3 and a flowing liquid containing 8-hydroxyquinoline (Q) and one of two polymers (polystyrene, PS, and polymethyl methacrylate, PMMA). Three factors influenced the luminescence of the (Alqx)/Al2O3 nano colloids. The first factor was whether the 8-hydroxyquinoline was added before or after laser ablation. The second factor was if the reaction medium consisted of (1) Q dissolved in ethanol, (2) Q dissolved in cyclohexane containing PS, or (3) Q dissolved in ethyl acetate containing PMMA. The third factor affecting luminescence was the age of the colloids. The (Alqx)/Al2O3 nano colloid product was characterized by transmission electron microscopy (TEM), ultraviolet visible spectroscopy (UV-vis), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and fluorescence spectroscopy. The product from all three-reaction media luminesced when irradiated with ultraviolet light. The product formed in cyclohexane containing PS gave the greatest luminescence, followed by the product formed in ethanol, and the product formed in ethyl acetate containing PMMA gave the smallest luminescence. The luminescence mechanism is similar to that of Alq3.