Finding Order in Chaos: Vibrational Spectroscopy Study of Oriented Soft Materials

在混沌中寻找秩序：定向软材料的振动光谱研究

• 批准号: RGPIN-2020-05098
• 负责人: Pellerin, Christian
• 金额: $ 3.5万
• 依托单位: Université de Montréal
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=716672
• 关键词: Finding; Order; Chaos; Vibrational; Spectroscopy

The properties and performance of soft materials depend on their chemical nature and on their molecular structure: how the molecules are arranged within the material. The orientation of molecules is a critical aspect of materials structure. It plays a large role in high-performance fibers, in films that extend food shelf-life, in televisions and flat screens, etc. Our group specializes in the study of orientation: we develop new techniques of vibrational spectroscopy to better analyze orientation and we create orientation in otherwise chaotic (amorphous and disordered) materials to improve their properties. This research targets three specific objectives in line with our existing program on oriented materials. First, we want to gain a fundamental understanding of "photomobility" in materials containing azobenzene (azo) chemical units. In this intriguing phenomenon, irradiation with polarized light induces a molecular-scale isomerization of the azo that leads to an intermediate scale orientation and finally to large-scale motion. We will apply vibrational spectroscopy and other tools to better understand the highly debated mechanism of photomobility. The second objective is to optimize the molecular design of azomaterials for efficient "photomechanical" applications where light energy is converted into motion or work. We will use, among others, a time-resolved spectroscopy method (developed in our lab) to study the role of the glass transition temperature, the bulkiness of the azo, its isomerization efficiency, etc., on light-induced orientation and motion. Finally, we will develop new methods of vibrational spectroscopy that will sidestep limitations of the existing techniques to measure orientation. We will apply them to nanofibers prepared by electrospinning, a technique with highly promising application prospects but whose widespread use is limited by our poor control of the properties of nanofibers. Our research is innovative and, thanks to our specific expertise and state-of-the-art infrastructure, it could not be conducted elsewhere in the world. It will have significant impact at three levels. First, it will contribute to the training of 20 students in the thriving field of materials science. Our previous students are now active in research and industry in Canada and abroad. Second, we will cast new light on the role of orientation in amorphous materials and on the exciting phenomena of photomobility and mass transport in azomaterials. This knowledge will help optimize the performance of partially ordered soft materials. Our new spectroscopy techniques should also be adopted by other researchers worldwide. Finally, we will have an immediate practical impact thanks to our ongoing collaborations with industrial and military partners who seek our expertise in orientation and spectroscopy to improve their real-world applications.

软材料的性质和性能取决于它们的化学性质和它们的分子结构：分子如何在材料内排列。分子的取向是材料结构的一个重要方面。它在高性能纤维、延长食品保质期的薄膜、电视和平面屏幕等方面发挥着重要作用。我们的团队专门研究取向：我们开发了新的振动光谱技术来更好地分析取向，我们在混乱（无定形和无序）的材料中创造取向，以改善它们的性能。