Nanoparticles from a Gold Complex with Sulfite Ion as Ligand: Preparation and Characterization

ABSTRACT

Gold colloidal nanoparticles (GNPs) were prepared by reducing a complex of Au⁺. Na₃Au(SO₃)₂ with sodium citrate. The procedure provides control of the dimension of nanoparticles produced, which is a function of reaction time and concentration of reactants. The nanoparticles were separated by centrifugation and their characteristics and dimensions were studied using UV-Vis and IR spectroscopy and transmission electronic microscopy (TEM).     

Aluminablasting of human tooth enamel

As part of a programme aimed at enhancing the degree of bonding that can be developed between dental polymer and human tooth enamel, the enamel has been subjected to two types of pretreatment, namely, aluminablasting (a mechanical etching) and aluminablasting followed by surface etching with orthophosphoric acid. Analysis of the surfaces so prepared by scanning electron microscopy has shown that enamel patterns with different degrees of retention ability have been obtained, and that the surfaces should be capable of bonding with dental polymer.