Effect Titanium Dioxide / Paraloid B.72 Nanocomposite Coating on Protection of Treated Cu-Zn Archaeological Alloys

Abstract

Copper alloy samples are subjected to climate chamber test to simulate corrosion compounds of copper artifacts in atmospheric environment. Relative humidity and air pollution considered as an essential source of deterioration and corrosion of archaeological objects. Corroded copper coupons were investigated by X-ray diffraction analysis (XRD) and scanning electron microscopy with energy dispersive X-ray analysis (SEM-EDX) to identify elemental composition of coupon samples and the corrosion products. Mechanical cleaning was used in order to clean the copper coupon surface and carried out nanocomposite coating on treated copper surface. To evaluate performance of titanium dioxide TiO 2 / Paraloid B.72 nanocomposite, the nanocomposite coating applied as a thin film at different times (10, 15, 30 minutes). The electrochemical impedance spectroscopy (EIS) of nanocomposite coating layers on treated copper coupons showed different results; that the best layer was obtained from the coupon which immersed in nanocomposite coating for 15min. To prove successes of TiO 2 / Paraloid B.72 nanocomposite as a good protection coating applied on treated copper objects. Nanocomposite coating of TiO 2 / Paraloid B.72 were examined under X-ray diffraction analysis (XRD), Raman Spectroscopy, Atomic Force Microscopy (AFM), and Contact angle, which revealed control the wettability and TiO 2 / Paraloid B.72 nanocomposite is completely covers and protects the copper substrate without any degradation.

Application of Inorganic Nanomaterials in Cultural Heritage Conservation, Risk of Toxicity, and Preventive Measures

“…Details about different nanocomposites with specific properties for the protection of different substrates [148] include, for example, combinations of Titanium oxides in mixtures such as TiO 2 -Paraloid 72 (Cu-Zn alloys pieces) [155], hybrid compounds of siloxane with nanosilica-siloxane (water repellent) [156], nano Ca(OH) 2 (marble) [157], TiO 2 -SiO 2 in the form of tetraethylorthosilicate (Theos) for marble [158], or TiO 2 -SiO 2 -polydimethylsiloxane, also known as PDMS (limestone) [159]. Likewise, their mixtures include combinations of ZnO-TiO 2 -Paraloid 72 (pottery), hydroxyapatite-Theos-PDMS for applications in sandstones, or silicon-based compounds with calcium oxalates for stone consolidation [147].…”

Evaluation of Nanolime-Silica Core-Shell for Consolidation of Egyptian Limestone Samples with Application on an Archaeological Object

“…The composition of the prepared nanolime-silica core-shell was analyzed by X-ray diffraction model (JEOL) at National Research Centre (NRC), Egypt. This analysis was done according to Gharib et al [15] under the following conditions: operating voltage: U = 35kV, current I = 30 mA, X-rays from a copper cathode (Cu), wavelength Cu Kα = 1.5418A, 4 -100° 2θ, step: 0.1°, Speed: 2/min.…”

“…The measurement of contact angle was performed by contact angle analyzer model T330 manufacture by Biolin Scientific, Finland, at Egypt Nanotechnology Center, Cairo University, Egypt. This measurement of contact angle for the treated limestone samples was determined according to Gharib et al [15], where droplet distilled water volume 4 μm was applied on the sample and the image of the water droplet was captured. It should be mentioned that the measure time 10 s. In this test, one sample from every aged treated sample with 5% and 10% concentrations of lime-silica core-shell was used for conducting this test.…”

“…Because of its high porosity, water and moisture are regarded one of the most deteriorating factors for limestone artefacts. As a result, the water resistance of conservation materials should be measured [15], which was done with the core-shell employed in this work. Mechanical property measurements were critical in evaluating the materials utilized in the consolidation process [15,21].…”

Evaluation of 3a-Hydroximasticadienoic Acid as a Corrosion Inhibitor for Silver in Saline Environment

“…In this concentration, it can be attributed to desorption the organic molecules (3-HM). In this case, the system is controlled by charge transfer resistance, as it only shows a time constant (4,5). Making the corresponding adjustment with an equivalent electrical circuit (Figure 3), where Rs is solution resistance, Rct is charger transfer resistance and CPE1 is Constant phase element and the results are shown for the different working conditions of silver with 3-HM acid in Table I.…”