Zhang Zhehan, Huang Qin, Sun Jiaxing, Hao Qilong, Zhang Wenyuan, Yu Zongren, Su Bomin, Zhang Haixia
State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, China.
Gansu Provincial Research Center for Conservation of Dunhuang Cultural Heritage, Dunhuang Academy, Dunhuang 736200, China.
Molecules. 2025 May 12;30(10):2136. doi: 10.3390/molecules30102136.
Red lead (PbO) has been extensively utilized as a red pigment for centuries. However, the discoloration and blackening of red lead in historical paintings have significantly compromised the aesthetic value of mural artworks. Investigating the mechanisms behind the blackening of PbO is of paramount importance. This study examined the effects of four kinds of reactive oxygen species (ROS) on the aging process of PbO in an alkaline environment. Specifically, singlet oxygen (O), superoxide radical (O·), hydrogen peroxide (HO), or peroxynitrite (ONOO) was individually reacted with PbO. The resulting products were analyzed qualitatively and quantitatively using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy-energy-dispersive spectroscopy (SEM-EDS), Raman spectroscopy, inductively coupled plasma mass spectrometry (ICP-MS), and UV-Vis spectroscopy. The findings indicate that singlet oxygen (O) and superoxide radicals (O·) effectively induce the aging of PbO, whereas hydrogen peroxide (HO) and peroxynitrite (ONOO) exhibit little impact on its aging. This research elucidates the aging mechanisms of PbO in alkaline environments and provides valuable insights for the preservation and restoration of mural paintings.
几个世纪以来,红丹(PbO)一直被广泛用作红色颜料。然而,历史画作中红丹的褪色和变黑严重损害了壁画艺术品的美学价值。研究PbO变黑背后的机制至关重要。本研究考察了四种活性氧(ROS)在碱性环境中对PbO老化过程的影响。具体而言,单线态氧(O)、超氧阴离子自由基(O·)、过氧化氢(HO)或过氧亚硝酸根(ONOO)分别与PbO反应。使用X射线衍射(XRD)、X射线光电子能谱(XPS)、扫描电子显微镜-能量色散光谱(SEM-EDS)、拉曼光谱、电感耦合等离子体质谱(ICP-MS)和紫外-可见光谱对所得产物进行定性和定量分析。研究结果表明,单线态氧(O)和超氧阴离子自由基(O·)能有效诱导PbO老化,而过氧化氢(HO)和过氧亚硝酸根(ONOO)对其老化影响不大。本研究阐明了碱性环境中PbO的老化机制,为壁画的保护和修复提供了有价值的见解。