Synthesis and characterization of nanostructured bao solutions: application in conservation of wall paintings

This paper shows a study about the preparation and characterization of nanostructured BaO suspensions and their evaluation as consolidant products for lime stone supports. Product preparation was made by chemical synthesis of coprecipitation in non-aqueous solutions of barium acetate [Ba (CH3CO2)2] and sodium hydroxide [NaOH] reagents, with the use of ethylene glycol as a reaction medium. The nanoparticles were characterized by transmission electron microscopy (TEM) showing that all syntheses carried out with different experimental conditions gave a 20-50 nm particle size. This paper also evaluated the first results on the application of synthesized BaO on samples of wall paintings by optical microscopy (OM), scanning electron microscopy (SEM-EDX) and colorimetry. The results indicate that the nanostructurated BaO products may have a protection or pre-consolidation function on wall paint layers. The superficial application of the product forms a thin layer, compatible with the chemical nature of the wall painting and produces a consolidating action, on the surface.