A Comparison Study of Titanium Dioxide and Zinc Oxide Nanoparticles for Cleaning Archaeological Pottery

Abstract

Many excavations contain potsherds that have suffered from different aspects of deterioration, including salt crystallization, dirt deposition, and soot. The different stains play an important role in the deterioration of archaeological pottery, such as the disappearance of the original surface and discoloration. The present study aims to evaluate some nanoparticles in an innovative poultice form to be used to clean archaeological pottery. In this study, the nanoparticles (NPs) of titanium dioxide (TiO2) and zinc oxide (ZnO) have been prepared at 5% and in the poultice form to be used for the cleaning process of archaeological potsherds excavated from the excavation site at Abusir. Different analytical techniques, such as transmission electron microscope (TEM), digital microscope, stereomicroscope, scanning electron microscope (SEM-EDX), X-ray diffraction (XRD), and measurement of color change have been used to characterize the studied potsherds and evaluate the cleaning process. The results of the XRD analysis showed the presence of some main minerals, such as albite, quartz, diopside, hematite, spinel and chloride salt (halite). The results of the microscopic investigation used in the evaluation process revealed that using TiO2 NPs poultice perfectly removed soot and dust deposits from the surface, and the cleaned surface became smooth. The results of elemental analysis by (SEM-EDX) showed the effective reduction in the percentage of salts and soot from the treated potsherds by TiO2 NPs poultice to be 3.38% and 6.68%, respectively. The measurement of color change revealed that the treated potsherds by TiO2 NPs poultice gave the highest (ΔE*=9.41), confirming this poultice's effective role in cleaning archaeological potsherds. Based on the results of different analytical techniques used in the evaluation process, the TiO2 NPs poultice is recommended for use in the cleaning process of archaeological pottery.