高分子科学系列讲座第357讲,Prof. Joachim Loos,Printable/Organic Electronics

文章来源:    发布时间:2024-04-01
报告题目:Printable/Organic Electronics(NO.PSLAB357-PS2024-02)
报 告 人:Prof. Joachim Loos
单  位:华南理工大学前沿软物质学院

    Since the first images and electron diffraction patterns of polyethylene single crystals acquired by TEM in the late 50ties of last century, which have yielded to our understanding of folded-chain polymer crystals, Transmission Electron Microscopy (TEM) characterization has played a leading role for exploring the micro- and nanoscale organization of polymer materials. One of the distinctive capabilities of TEM is to provide real space images and to perform structural analyzes by electron diffraction at the same specimen feature. During the last decades, utilizing TEM has resulted in continual new insights on so-called structure-property relations, i.e. it has created understanding on how the chemical structure of the polymer material and the chosen processing conditions influence morphology formation and the resulting properties. 

  In the last 10-20 years, utilizing of TEM in condensed matter and life science research was advanced by many technological developments. To name but a few, correctors have substantially improved the quality of electron lenses so that 50 pm spatial resolution is achieved; TEM columns and specimen holders are designed for handling specimens in liquid or at liquid nitrogen/helium temperatures, where the latter substantially increases the “lifetime” of a specimen and allows for characterization of vitrified specimens; and modern cameras and detectors are able to sense single electron events. Condensed matter and life science research have benefit extraordinarily from these technological inventions; however, in the area of polymer science and technology still mainly traditional methodologies are applied. 

Therefore, in the main part of my presentation, I will discuss advanced but not well-recognized TEM-based methodologies for polymer morphology characterization, like Scanning Transmission Electron Microscopy (STEM), Electron Tomography (ET) of 100 nm to 4000 nm thick samples, and chemical imaging by Energy-Dispersive X-ray spectroscopy (EDX) and Electron Energy Loss Spectroscopy (EELS). I will show examples from polymer blends and rubbers, nano-composites, and organic electronics.