Self-Healing Photochromic Polymeric Coatings

研究目的和方法本研究是关于开发新一代聚合物材料，这种材料在机械损伤时会在受损区域发生着色，但暴露在电磁辐射、酸性蒸汽和/或高温下会导致受损区域的自我修复和原始颜色的恢复。拟议研究的目标有三个方面：(1)开发能够感知和自我修复的新材料平台；(2)了解在颜色诱导的自我修复过程中导致协调的化学和机械变化的分子和宏观过程；以及(3)将导致快速创新的性能和设计优化。这项研究的方法将是精确地合成和设计具有光致变色成分和可变共聚组成的新一代聚合物材料，以提供这些难得的先进性能。使用分子和热机械探头的组合，我们将对导致自我修复的过程有基本的理解。结合化学成像、可控损伤评估以及对受损和修复区域的热和粘弹性属性的空间分布分析，将使我们能够充分阐明导致这一独特行为的分子和宏观事件之间的关系。如果成功，这项研究的好处将包括许多独特的应用，从多级传感设备到“智能”涂层，以及延长材料原始完整性的使用寿命，这将彻底改变社会需求。这些将包括内置分子传感器的复合材料结构，使航空工业能够及早评估和预防潜在的灾难性事件，及早检测腐蚀和退化过程，设计机械可变设备等。我们预计，这些刺激响应性自我修复材料将在制药、医疗、个人护理、电子、能源和相关行业发挥重要作用。如果成功，将通过“绿色”化学方法建立一种新的技术范例，对环境的影响最小或没有影响，创造可持续的材料方法来解决关键的技术挑战。拟议中的研究对社会的另一个好处是发展受过高等教育的劳动力，这些劳动力将应对科学和技术挑战，从而增强美国的技术优势。

Research Objective and ApproachThis research is about the development of a new generation of polymeric materials that upon mechanical damage undergo coloration in a damaged area, but exposure to electromagnetic radiation, acidic vapors, and/or elevated temperatures will result in self-repair of the damaged area and revitalization of the original color. The objectives of the proposed research are three fold: (1) development of a new platform of materials capable of sensing and self-healing, (2) understanding of molecular and macroscopic processes leading to orchestrated chemical and mechanical changes during color-induced self-repairs, and (3) property and design optimization that will lead to rapid innovation. The approach of this research will be to precisely synthesize and engineer a new generation of polymeric materials with photochromic components and variable copolymer compositions that offer these rarely obtainable advanced properties. Using a combination of molecular and thermo-mechanical probes we will develop fundamental understanding of processes leading to self-healing. Combining chemical imaging, controllable damage assessment, and analysis of spatial distribution of thermal and viscoelastic attributes of damaged and repaired areas will allow us to fully elucidate the relationship between molecular and macroscopic events responsible for this unique behavior.Benefits to SocietyIf successful, the benefits of this research will include many unique applications ranging from multi-level sensing devices to "smart" coatings, and extended lifetimes of materials' original integrity that will revolutionize societal desires. These will include composite structures with build-in molecular sensors, allowing early assessment and prevention of potentially catastrophic events in airspace industries, early detection of corrosion and degradation processes, engineering of mechano-mutable devices, and many others. We envision that these stimuli-responsive self-repairing materials will play a vital role in the pharmaceutical, medical, personal care, electronic, energy, and related industries. If successful, a new technological paradigm through "green" chemistry approaches, with minimal or no impact on the environment creating sustainable material approaches to solve critical technological challenges, will be established. Another benefit to the society of the proposed research will be the development of the highly educated workforce that will tackle scientific and technological challenges leading to the enhancement of US technological superiority.