SYNTHESIS AND CHARACTERIZATION OF AN ECO-FRIENDLY MATERIAL FOR STONE MONUMENTS PREZERVATION STARTING FROM THE EGGSHELLS.

Conservation and restoration of heritage structures represents a highlighted issue, the main challenge being to bring the cultural objective to its original state, or as close as possible to it by using eco-friendly materials with lover impact on the environment and human health. Within this study, the calcium zincate nanoparticles have been synthesized starting from the eggshels wastes through the precipitation method. For this purpose, the raw eggshells were washed for organic traces removal and disolved in concentrated HCl solution to form CaCl2. The Ca(Zn(OH)3)2•2H2O was obtained by adding into the chemical reaction media a solution of zinc acetate dihydrate previously dissolved in 100mL of methanol under vigorous stirring at room temperature and precipitating with NaOH 12M solution. The white precipitate was characterized by field emmision scanning electron microscope (SEM), X-Ray diffraction (XRD) and thermal analyses (DTA-TG). The Scherrer equation result showed the nanometric size of calcium zincate crystallite, about 23nm. [ABSTRACT FROM AUTHOR]