Spectroscopic Investigation of Electrospun Nanofibers

我的团队研究软材料(聚合物、超分子组件和分子玻璃)的结构和性质，并开发先进的光谱技术(如偏振拉曼光谱和时间分辨红外光谱)。我们的经验和世界领先的基础设施为我们提供了在电纺领域做出创新贡献的独特机会。 静电纺丝是一种非常受欢迎的纳米纤维生产方法，这要归功于它的实验简单性和惊人的多功能性。电纺纤维目前用于选择性膜、组织工程和其他生物医学应用，但将其应用于传感器、能量转换、催化和光电子器件等技术应用的兴趣越来越大。不幸的是，我们对纳米纤维的结构和性能的了解，以及它们如何受到电纺过程的影响，仍然是零散的。分子取向经常被引用为一个关键参数，但它很难量化。我的团队最近在单个纤维尺度上展示了振动光谱学的力量，以实现这种量化并回答该领域的其他重要问题。 在这种背景下，我的项目试图利用最先进的振动光谱学来了解和控制电纺纤维的结构和性能。我们将研究电纺纤维的五个关键方面，具体目标是：1)了解纤维中的分子取向及其对其性能的影响；2)演示和控制电纺过程中聚合物链的解缠；3)通过时间分辨红外研究加深对电纺的理解；4)了解在电纺过程中形成晶型的原因和位置；以及5)了解共混对纤维微观结构的影响。为了实现这些雄心勃勃的目标，我们将使用我们的主力拉曼技术与红外光谱技术相结合，包括加拿大第一台纳米红外仪器，以及各种补充技术。 我们的研究是创新的，无法在世界其他地方进行。这应该会极大地改善目前对电纺纤维结构的理解，以及当它们达到纳米级时它们的不寻常性质。它将允许确认和解释可能具有变革性的观测结果，例如部分解缠和多晶型形成。我们的工作还将导致振动光谱学的重大仪器发展，这将适用于材料科学的其他领域。总体而言，我们的工作将提高我们优化纳米纤维性能的能力，并有助于使其前景广阔的技术应用成为现实。

My group studies the structure and properties of soft materials (polymers, supramolecular assemblies and molecular glasses) and develops advanced spectroscopy techniques (such as polarized Raman and time-resolved infrared spectroscopy). Our experience and world-leading infrastructure provide us a unique opportunity to make innovative contributions in the field of electrospinning. Electrospinning is an extremely popular method for producing nanofibers thanks to its experimental simplicity and amazing versatility. Electrospun fibers are currently used in selective membranes, tissue engineering and other biomedical applications, but there is a growing interest in applying them for technological applications in sensors, energy conversion, catalysis and opto-electronic devices. Unfortunately, our understanding of the structure and properties of nanofibers, and how they are affected by the electrospinning process, remains fragmentary. Molecular orientation is often invoked as a critical parameter but it is challenging to quantify. My group has recently demonstrated the power of vibrational spectroscopy at the individual fiber scale to do this quantification and answer other important questions in the field. In this context, my program seeks to understand and control the structure and properties of electrospun fibers using state-of-the-art vibrational spectroscopy. We will study five key aspects of electrospun fibers, with the specific objectives of: 1) Understanding molecular orientation in fibers and its impact on their properties; 2) Demonstrating and controlling disentanglement of polymer chains during electrospinning; 3) Enabling a deeper understanding of electrospinning through time-resolved infrared studies; 4) Understanding why and where polymorphs form during electrospinning; and 5) Understanding the effect of blending on fiber microstructure. To reach these ambitious objectives, we will use our workhorse Raman technique in combination with IR spectroscopy, including the first nanoIR instrument in Canada, and various complementary techniques. Our research is innovative and could not be conducted elsewhere in the world. It should greatly improve the current understanding of the structure in electrospun fibers and their unusual properties when they reach the nanoscale. It will allow confirming and explaining possibly transformative observations, such as partial disentanglement and polymorph formation. Our work will also lead to significant instrumental developments in vibrational spectroscopy that will be applicable to other fields of materials science. Overall, our work will improve our ability to optimize the properties of nanofibers and contribute to making their promising technological applications a reality.