New approach for deacidification and consolidation of bone artifacts

Abstract

Acidic conditions affect the archaeological bone in the burial and in uncontrolled display and storage environment or due to improper restoration processes. Accordingly, bones become weak and fragile. This study aims to evaluate nano calcium propionate and nano styrene butyl acrylate (used for the first time in the treatment of bones) at different concentrations for deacidification and consolidation of fragile bones. New bone samples were prepared. Artificial accelerated aging (acid and heat) was applied to prepare aged untreated samples. Deacidification and consolidation processes using the materials mentioned above were applied. The analytical techniques used were transmission electron microscope (TEM) and thermal gravimetric analysis (TGA) were used for morphological and thermal stability investigation for the prepared nano styrene butyl acrylate copolymer and its calcium propionate nonocomposites, a digital microscope and scanning electron microscope (SEM) for investigation of the surface morphology, pH value measurement, change of color measurement, attenuated total reflection—Fourier transform infrared spectroscopy (ATR/FTIR), contact angle (wettability), and X-ray diffraction analysis for measurement of bone crystallinity. The results proved that acid-heat aging affected bone properties such as changes in surface morphology and color, decrease in pH value, and contact angle. Bone samples became more crystalline, and the chemical composition of bone was also affected. The treatment of aged untreated bone samples with the materials used in this study improved their properties, such as increasing the pH value and contact angle. The surface morphology, color change, and crystallinity of bone improved and became more stable.