Spectroscopic analysis for evaluation the nano silica as an inorganic and hybrid nano material in treatment of red cinnabar pigment – Based on case study at the Grand Egyptian Museum

Abstract

One of the most important funerary objects during ancient Egyptian history was the canopic chests, which varied in shape and objective during different ages. Part of a painted wooden canopic chest which dated between the late 27th dynasty (525 BC - 404 BC) to the Greco-Roman period and stored now at the storage rooms of the Grand Egyptian Museum in Giza, Egypt; used as a case study to do an experimental study through designing mimic samples to the object structure, which mainly was wooden support of Ficus Sycamore wood species, covered with white preparation layer of Calcium Carbonates (CaCo3), with a variety of colors for the painting layer; but in our research we concentrate on the red pigment which has been identified as Cinnabar, which from its conservation state was suffering from darkening, cracks, microcracks, and fragility. The experimental study conducted mainly to evaluate the performance of the nano silica for the treatment of the red cinnabar pigment as a consolidation material in two different forms: the inorganic and hybrid; in the inorganic form the nano silica has been dispersed in 2-propanol organic solvent, and its hybrid form the nano silica dispersed in Klucel E organic polymer. and to get accurate results that can be reliable in the field of conservation, various analytical and examination methods have been applied such as scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), Fourier transform infrared (FT-IR), and Laser-induced breakdown spectroscopy (LIBS). Prior to the elemental characterization of data samples, the local thermodynamic equilibrium (LTE) condition was established to guarantee the correctness of the LIBS analysis. The results revealed the high efficiency of using nano silica in the inorganic form (dispersed in 2-propanol) than the same material but in hybrid form (dispersed in Klucel E) in regard of absorption of the materials in the matrix and the final appearance of the samples surfaces.