Collaborative Research: Modern Oil-based Paints: A Mechanistic Approach to Assessing and Modeling their Curing, Aging and Cleaning

技术摘要：在文化遗产科学的背景下对涂料的研究提出了一系列独特的技术挑战，因为材料的性能随着时间的推移而演变，太长了，不能直接复制。因此，需要老化过程的数据驱动的动力学模型，以了解老化涂料的物理状态，并制定有效的修复和清洁策略。在这项涉及西北大学和芝加哥艺术学院的合作项目中，将开发涂料固化和老化的动力学蒙特卡罗模型，以及确定相关模型参数所需的实验系统。最终的结果将是一组模拟模型，这些模型可以被视为“虚拟的”油基涂料。这些“虚拟”涂层将使人们能够跟踪复杂、多组分涂料的随时间变化的结构特征。这些模型具有实验确定的输入参数，代表了油基涂料的物理和化学知识库，将作为解决广泛问题的平台。要解决的具体问题涉及系统在高温、潮湿和各种清洁溶液中的固化和老化。用石英晶体微天平(QCM)作为主要实验工具，对由表征良好的原料制成的涂层的动力学参数进行实验测定。纳米压痕将被用来将QCM获得的高频机械响应与机械响应的补充措施和实际涂料样品相关联。虽然这些技术将直接应用于艺术家使用的油基涂料，但该方法广泛适用于各种领域，包括高性能防护涂料的表征，以及可持续生物衍生材料的开发。非技术性总结：这个项目是西北大学和芝加哥艺术学院的合作成果。将使用最先进的科学工具来研究现代油基涂料的固化和老化特性以及保护处理对它们的影响。尽管油基涂料在整个20世纪被广泛使用，并在那个时期的一些最著名的艺术品中使用，但人们对它们的性质知之甚少。提高我们在这一领域的知识对于为子孙后代保护这些艺术品的完整性至关重要。这项研究的结果将被用来为艺术学院和世界各地其他博物馆收藏的绘画制定更有效的保护战略。还将与艺术学院博物馆教育系合作，开发一个将科学和艺术联系起来的教育外展元素。将开发外展产品，以吸引初中和高中的科学课程来到博物馆。这些活动将旨在吸引那些原本不太可能被科学相关项目吸引的学生。同样，与艺术学院的联系将使西北大学的本科生和研究生能够理解科学概念如何造福于传统科学领域以外的学科。

TECHNICAL SUMMARY: Investigations of paint coatings in the context of cultural heritage science present a unique set of technical challenges because of the evolution of the properties of materials over time scales that are much too long to be reproduced directly. As a result, data-driven kinetic models of the aging process are needed in order to understand the physical state of aged paints and to develop effective restoration and cleaning strategies. In this collaborative project involving Northwestern University and the Art Institute of Chicago, a kinetic Monte Carlo model of paint curing and aging will be developed, as will experimental systems needed to determine relevant model parameters. The net result will be a set of simulation models that can be viewed as 'virtual' oil-based paint coatings. These 'virtual' coatings will enable the time dependent, structural features of complex, multicomponent paint coatings to be tracked. The models, with their experimentally determined input parameters, represent a physical and chemical knowledge base for oil-based paint coatings that will serve as a platform for addressing a wide range of questions. Specific issues to be addressed concern the curing and aging of systems when subjected to heat, humidity and various cleaning solutions. Kinetic parameters will be determined experimentally with coatings made from well characterized starting materials, using the quartz crystal microbalance (QCM) as the primary experimental tool. Nanoindentation will be used to correlate the high frequency mechanical response obtained with the QCM to complementary measures of the mechanical response and to actual paint samples. While these techniques will be applied directly to oil-based coatings used by artists, the methodology is broadly applicable in a variety of areas, including characterization of high performance protective coatings, and the development of sustainable, bio-derived materials. NON-TECHNICAL SUMMARY: This project is a collaborative effort between Northwestern University and the Art Institute of Chicago. State-of-the art scientific tools will be used to study the curing and aging properties of modern oil-based paints and the impact of conservation treatments on them. Although oil-based paints were widely used throughout the 20th century, and in some of the most prominent artworks of that period, their properties are poorly understood. Advancing our knowledge in this area is crucial for preserving the integrity of such artworks for future generations. The results of this research will be used to develop more effective conservation strategies for paintings in collections at the Art Institute and at other museums throughout the world. An educational outreach element linking science and art will also be developed in conjunction with the Art Institute's Department of Museum Education. Outreach offerings will be developed to attract middle school and high school science classes to the museum. These activities will be designed to attract students to science who would otherwise not likely be drawn to science-related programs. Similarly, the connection with the Art Institute will enable undergraduate and graduate students at Northwestern to understand the ways in which scientific concepts can benefit disciplines that lie outside the traditional scientific realm.