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.

软材料的特性和性能取决于其化学性质和分子结构：分子在材料内的排列方式。分子的取向是材料结构的一个关键方面。它在高性能纤维、延长食品保质期的薄膜、电视和平板屏幕等领域发挥着重要作用。我们的小组专门研究取向：我们开发振动光谱新技术以更好地分析取向，并在其他混沌（无定形和无序）材料中创建取向以改善其性能。 这项研究的三个具体目标与我们现有的定向材料计划一致。首先，我们希望对含有偶氮苯 (azo) 化学单元的材料的“光迁移性”有一个基本的了解。在这个有趣的现象中，偏振光照射会引起偶氮分子的分子尺度异构化，从而导致中间尺度的取向，并最终导致大规模的运动。我们将应用振动光谱学和其他工具来更好地理解备受争议的光迁移机制。第二个目标是优化偶氮材料的分子设计，以实现高效的“光机械”应用，将光能转化为运动或功。除其他外，我们将使用时间分辨光谱方法（我们实验室开发的）来研究玻璃化转变温度、偶氮的体积、其异构化效率等对光诱导取向和运动的作用。最后，我们将开发新的振动光谱方法，以避开现有技术测量方向的局限性。我们将把它们应用到静电纺丝制备的纳米纤维上，静电纺丝技术具有广阔的应用前景，但由于我们对纳米纤维性能的控制不佳，限制了其广泛使用。 我们的研究具有创新性，并且由于我们特定的专业知识和最先进的基础设施，它无法在世界其他地方进行。它将在三个层面产生重大影响。首先，它将有助于在蓬勃发展的材料科学领域培养 20 名学生。我们以前的学生现在活跃在加拿大和国外的研究和工业领域。其次，我们将对非晶材料中的取向作用以及偶氮材料中令人兴奋的光迁移率和质量传输现象进行新的阐述。这些知识将有助于优化部分有序软材料的性能。我们的新光谱技术也应该被世界各地的其他研究人员采用。最后，由于我们与工业和军事合作伙伴的持续合作，我们将产生立竿见影的实际影响，他们寻求我们在定向和光谱方面的专业知识来改善他们的实际应用。