Mohamed Niazy Mostafa, Orabi Ezz Arabi, Alamri Abdullah A, Mashlawi Abadi M, El-Shabasy A, Taleb Thanaa Ali Abo
Faculty of Archaeology, Conservation Department, Aswan University, Aswan, Egypt.
Physical Sciences Department, Chemistry Division, College of Science, Jazan University, P.O. Box. 114, Jazan, 45142, Kingdom of Saudi Arabia.
Sci Rep. 2025 May 6;15(1):15756. doi: 10.1038/s41598-024-84752-y.
In recent years, the study of the deterioration phenomena and factors of oil paintings has attracted great attention from the scientific community. However, the number of articles that contain a study of the phenomenon of rust damage on paintings and an explanation of the mechanism of damage on canvas is small, so this article focused on studying the effect of rust resulting from the use of iron nails in fixing the canvas holder and due to aging and exposure to damaging conditions on colors containing metals (red-yellow-blue) in oil paintings, which results in damage products from rust, and different on the surface appearance of the colors and change the chemical composition of the color. This article aims to discuss (1) the phenomenon of rust that affects paintings (2) the problems associated with the effect of rust that migrates through the layers on the rest of the parts of the painting other than the colors, such as the canvas layer and the preparation layer (3) describing the mechanism of atmospheric corrosion of iron by interacting with ground colors (red ochre-yellow ochre-blue) using experimental models covered with rust and exposed to thermal and light aging to evaluate damage before and after accelerated aging and the most important damage products (4) and the evaluation of damage was done by using color change measurement For the samples, the front and back morphological surfaces of the fabrics were monitored before and after aging through the average color measurements of the three colors. It became clear that the blue color shows the greatest change after complete aging in color ∆E = 42.7 Followed by red, which shows a complete change in color ∆E = 23.6, followed by yellow, which shows a complete change in color, ∆E* = 21.7. Microscopic examination showed that the rust was distributed in an uneven manner on the back surface of the fabric, and the front surface with the colors, and the appearance of large orange spots on the surface randomly, and the appearance of fine cracks penetrating the layers in the areas mixed with iron rust products, and their mixing with the color grains. The change in the chemical composition of the colors was monitored before and after aging by FTIR, EDS, which showed changes in terms of the appearance of the iron element (Fe) and an increase in its concentration after aging, which confirms that the color was affected by iron rust resulting from the rust of the iron nails fixed to the fabric layer stained with rust that migrates through the layers that are damaged due to the migration of Fe ions to the surface of the colors in the presence of alkaline metal cations in the chemical composition of the three earth colors. In the presence of moisture, the damage increases because the ionic diffusion across the thickness of the formed film leads to the disintegration of the paint because the polarization of the cathodic substrate encourages the migration of cations through the color layer, and the color change in the yellow and red colors resulted from the presence of the iron ion that reacts with Fatty acids in oil.
近年来，油画劣化现象及因素的研究引起了科学界的高度关注。然而，包含对绘画上锈损现象的研究以及对画布上损伤机制解释的文章数量较少，因此本文着重研究因使用铁钉固定画布支架、老化以及暴露于破坏条件下而产生的铁锈对油画中含金属颜色（红 - 黄 - 蓝）的影响，这种影响会导致铁锈产生损伤产物，使颜色的表面外观不同并改变颜色的化学成分。本文旨在探讨：（1）影响绘画的铁锈现象；（2）铁锈穿过各层迁移到绘画中除颜色之外的其他部分（如画布层和底料层）所产生的相关问题；（3）利用覆盖铁锈并经受热老化和光老化的实验模型，通过与底色（赭石红 - 赭石黄 - 蓝色）相互作用来描述铁的大气腐蚀机制，以评估加速老化前后的损伤情况以及最重要的损伤产物；（4）通过颜色变化测量对损伤进行评估。对于样品，通过对三种颜色的平均颜色测量来监测老化前后织物正面和背面的形态表面。结果表明，完全老化后蓝色的颜色变化最大，∆E = 42.7，其次是红色，颜色变化为∆E = 23.6，然后是黄色，颜色变化为∆E = 21.7。显微镜检查显示，铁锈在织物背面、有颜色的正面分布不均匀，表面随机出现大的橙色斑点，在与铁锈产物混合的区域出现穿透各层的细裂缝，且与色粒混合。通过傅里叶变换红外光谱（FTIR）、能谱仪（EDS）监测老化前后颜色化学成分的变化，结果表明铁元素（Fe）的外观出现变化且老化后其浓度增加，这证实颜色受到固定在织物层上的铁钉生锈产生的铁锈影响，铁锈通过各层迁移，在三种土色的化学成分中存在碱金属阳离子的情况下，由于铁离子迁移到颜色表面而导致各层受损。在有水分的情况下，损伤会加剧，因为穿过形成的膜厚度的离子扩散会导致漆膜解体，这是由于阴极基材的极化促使阳离子穿过颜色层，黄色和红色的颜色变化是由于铁离子与油中的脂肪酸发生反应所致。
