NANOCOMPOSITES FOR THE PROTECTION OF GRANITIC OBELISKS AT TANIS, EGYPT

Granite has widely been used in the fields of architecture and sculpture in Egypt, especially in the carving of obelisks, which were one of the most important features of ancient Egyptian civilization. Many granitic obelisks of Ramses II, were found in the ancient city Tanis (San el-Hagar), Nile Delta, Egypt, that has been considered one of the most important ancient Egyptian cities. Unfortunately, the granitic obelisks at Tanis have been subjected to many deterioration factors, which resulted in numerous deterioration aspects, such as granular disintegration, scaling or spalling, cracking, efflorescence, soiling, microbiological colonization. From this standpoint, the materials which are used in the protection of those granitic obelisks must have the property of hydrophobicity in order to protect them from the harmful effects of water. In the last decade, polymer-nanoparticle composites have attracted great interest in the field of culture heritage conservation due to their unique multifunctional properties, resulting from the high surface area and chemical activity of the nanoparticles dispersed in the polymers. In this paper, three types of nanocomposites (PF 4, Fluotanium, Fluozinc) were used for the protection of granitic samples collected from Tanis. The petrographical, mineralogical, and chemical study of the granitic samples were determined by means of polarizing microscope, X-ray diffraction, and X-ray fluorescence, respectively. The properties of the treated samples were estimated by visual examination, colormetric measurements, static water contact angle, total immersion water absorption, abrasion resistance, scanning electron microscope, and self-cleaning test. The durability of the nanocomposites used in this study was evaluated by repeating the measurement of static water contact angle for the treated granitic samples after exposure to ultraviolet irradiation.