COLLABORATIVE RESEARCH: WATER-MEDIATED TRANSPORT OF IONS AND MOLECULES IN IONOMERIC PAINT FILMS: AN INTEGRATED MULTI-TECHNIQUE INVESTIGATION

非技术摘要从14世纪到20世纪不可替代的艺术杰作由于油漆成分之间的化学反应而慢慢变质。 在这个复杂的过程中，被认为是重要的一步是离子和分子在油漆中的运动。 在本项目中，检查漆膜中的水和溶剂等材料的动力学和运输，以确定（1）该过程的性质，以及（2）影响该过程的因素。 漆膜是一种复杂的材料，必须采用多种技术进行研究，以尽可能完整地表征过程。 在材料研究部门的固态和材料化学计划以及化学部门的化学测量和成像计划的支持下，特拉华州大学和大都会艺术博物馆之间正在进行的合作，以解决与现代技术的绘画恶化，扩大了布鲁克海文国家实验室和太平洋西北国家实验室的科学家的参与，对大都会艺术博物馆和特拉华州大学准备的材料以及从受影响的艺术品中取出的显微镜样品进行额外的独特分析，以回答“为什么以及如何发生这个过程？和“可以采取什么样的行动来尽量减少或消除这些最终破坏无价艺术品的过程？“该项目通过大都会艺术博物馆和特拉华州大学开展的外展活动，为公众提供了科学发现与文化和历史元素之间的切实联系，同时它还发展了对复杂化学过程的理解，这些过程不仅仅影响绘画。 技术文摘含重金属的颜料与油画中的脂肪酸反应，产生金属羧酸盐，也称为肥皂。 这些皂可产生有损形象的夹杂物、表面结壳和/或增加的油漆透明度，导致不希望的和最终有害的影响。大多数油画在某种程度上都受到这个过程的影响。从科学的角度来看，该过程由一系列步骤组成：（1）通过油的水解产生游离脂肪酸;（2）酸和颜料衍生离子的迁移;（3）反应事件;和（4）产品的团聚以产生肥皂聚集体或迁移到漆膜表面以产生结壳。 每一步都很重要和复杂，部分原因是材料的异质性。该项目的重点是漆膜中材料的动态，主要是表征步骤2，但动态也很重要，因为水和溶剂等材料，有时来自修复干预，环境影响可能涉及步骤1和4。此外，由于这些材料是异质的，因此在理解这些过程的性质时，必须同时考虑诸如颜料粒度和形状以及涂料的孔隙率等性质的影响。 这只能通过多管齐下的方法来表征以不同方式处理的样品来实现。 通过结合大都会博物馆，特拉华州大学的优势，以及布鲁克海文国家实验室和太平洋西北实验室的专业知识，几项先进的技术被用于了解这一过程。提出的研究复杂异质多层系统的新策略适用于软物质科学领域类似问题的表征。

Non-technical AbstractIrreplaceable masterworks of art dating from the 14th century through the 20th century are slowly deteriorating due to chemical reactions among the paint components. One step believed to be important in this complex process is the movement of ions and molecules through the paint. In this project, the dynamics and transport of materials such as water and solvents in paint films are examined to determine (1) the nature of the process, and (2) what factors affect this process. Paint films are complex materials, and they must be studied with multiple techniques to characterize the processes as completely as possible. With the support from the Solid State and Materials Chemistry program in the Division of Materials Research and the Chemical Measurement and Imaging program in the Division of Chemistry, the ongoing collaboration between the University of Delaware and The Metropolitan Museum of Art to address the deterioration of paintings with modern technologies is expanded by the involvement of scientists at Brookhaven National Laboratory and Pacific Northwest National Laboratory to provide additional unique analyses of materials prepared at The Metropolitan Museum of Art and the University of Delaware and of microscopic samples removed works of art affected, to provide answers to questions like "Why and how does this process occur?" and "What types of actions can be taken to minimize or eliminate these processes that ultimately destroy priceless art objects?" The project, through outreach carried out by The Metropolitan Museum of Art and the University of Delaware, provides the public with a tangible connection between scientific discovery and the elements of culture and history, at the same time as it develops an understanding of complex chemical processes that affect more than just paintings. Technical AbstractThe reaction of heavy-metal-containing pigments with fatty acids in oil paintings, derived from the oil paint binders, produces metal carboxylates also called soaps. These soaps may produce disfiguring inclusions, surface crusts and/or increased transparency of the paints, resulting in unwanted and ultimately deleterious effects. Most oil paintings suffer from this process to some degree. From a scientific perspective, the process consists of a series of steps: (1) production of free fatty acids by hydrolysis of the oil; (2) migration of acids and pigment-derived ions; (3) the reactive event; and (4) agglomeration of the products to produce soap aggregates or migration to the paint film surface to produce crusts. Each step is important and complex, in part due to the heterogeneity of the material. This project focuses on the dynamics of materials in the paint films, predominantly characterizing step 2, but the dynamics are also important as materials like water and solvents, sometimes from restoration interventions, and environmental effects may be involved in steps 1 and 4. Additionally, because these materials are heterogeneous, one must simultaneously consider the effects of properties such as pigment particle size and shape, and porosity of the paint in understanding the nature of these process. This can only be achieved by a multi-pronged approach to characterize samples treated in different ways. By combining the strengths of the Metropolitan Museum, the University of Delaware together with expertise at Brookhaven National Laboratory and Pacific Northwest Laboratory, several sophisticated technologies are directed towards understanding the process. The novel strategy proposed to study a complex heterogeneous multilayered system is applicable to the characterization of analogous problems in the field of soft matter science.