Stain-free 3D mapping of polymer-blend morphologies

2022 Fiscal Year Final Research Report

• Project/Area Number: 21K18816
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 26:Materials engineering and related fields
• Research Institution: Nagoya University
• Principal Investigator: Muto Shunsuke 名古屋大学, 未来材料・システム研究所, 教授 (20209985)
• Project Period (FY): 2021-07-09 – 2023-03-31
• Keywords: ポリマーブレンド / 走査透過電子顕微 / 超高圧電子顕微鏡 / 電子エネルギー損失分光 / 次元削減

Outline of Final Research Achievements

This study developed a novel method for separating and visualizing polymer-specific chemical species by applying dimensionality reduction to spectrum image data obtained by electron energy loss spectroscopy (EELS) with scanning transmission electron microscopy (STEM). It was found that low acceleration voltage and room temperature conditions were the most damaging, primarily due to thermal damage caused by temperature increase. At an acceleration voltage of 1000 kV, some damage was observed at both room and low temperatures, primarily to C=C double bonds and benzene rings, but it was shown to have no effect on the visualization of the polymer species distribution. As a result, a technique for imaging polymer alloys without staining their components has been established.

Free Research Field

ナノ材料科学

Academic Significance and Societal Importance of the Research Achievements

特に厚い試料を透過観察及び分光測定のできる超高圧走査透過電子顕微鏡によるスペクトラムイメージ法と先端的画像処理法を組み合わせることによって，厚い試料のポリマーブレンドを構成する混合成分の無染色でのナノメートル分解能イメージングが可能であることを示すことができた．またLow-loss領域の強く重なり合うスペクトルを正しく分解することは，従来の手法の持つ欠点であったが、次元削減によるスペクトル分解法の中でも対数尤度最大化というテクニックを利用することで克服できることがわかった。