Development of a method to evaluate the index of interlayer strength and the structural phase transition for multi-walled carbon nanotubes by Raman shear vibration

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K21911
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 18:Mechanics of materials, production engineering, design engineering, and related fields
• Research Institution: Tohoku University
• Principal Investigator: Sato Yoshinori 東北大学, 環境科学研究科, 准教授 (30374995)
• Project Period (FY): 2019-06-28 – 2022-03-31
• Keywords: ラマンせん断振動 / 多層カーボンナノチューブ / 層間強さ / 構造相転移 / 機械強度 / 複合材料

Outline of Final Research Achievements

To take advantage of the strength of multi-walled carbon nanotube (MWCNT) in composites, it is necessary to have strong interactions between the layers of nanotubes to transfer the load to all layers of nanotubes, not only the outermost nanotubes are loaded. However, there is no method for evaluating interlayer strength at all. In this study, the shear vibration modes related between the layers of nanotubes were detected in the low-frequency region using Raman scattering spectroscopy. The deformation of nanotube structure caused the disappearance of the Raman shear vibration mode of MWCNT and the appearance of the Raman shear vibration mode of graphite, indicating the nanotube structure transforms into graphite.

Free Research Field

材料科学工学

Academic Significance and Societal Importance of the Research Achievements

本研究により、「MWCNTのラマンせん断振動モードの基礎研究」から「MWCNTの層間の強さ指標・円筒構造の歪み・構造相転移評価」までの一貫した研究基盤を世界にさきがけて行った。さらには、「層間と電気特性」などの異分野への発展や、六方晶窒化ホウ素チューブや金属硫化物チューブ等のチューブ状層状化合物における層間を評価する学術体系への発展にも期待できる。得られた結果は、CNT/セラミックス複合体やCNT/高分子複合体を開発する分野において、せん断振動の情報を用いれば、MWCNTの層間強さ指標や構造変形・構造相転移を簡易に評価でき、強力な評価ツールになりうる。