Development of Metal-Coated Cellulose Nanofibers and Their Application as Energy-Conducting Fillers

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K14421
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 26030:Composite materials and interfaces-related
• Research Institution: Kyoto Municipal Institute of Industrial Technology and Culture
• Principal Investigator: Noguchi Hiroki 地方独立行政法人京都市産業技術研究所, 京都市産業技術研究所, 次席研究員 (50796167)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: セルロースナノファイバー / 金ナノ粒子 / 導電性 / 複合樹脂

Outline of Final Research Achievements

In this study, Au nanoparticles densely immobilized onto cellulose nanofibers (CNFs) were developed to be applied as electrical and thermal conductive fillers for resins.The immobilization of Au nanoparticles onto CNFs were conducted in three steps: cationization of the CNFs surface, adsorption of Au ions, and reduction. By using ascorbic acid as the reducing agent and CNFs concentration of 0.01 wt% during the reduction process, Au nanoparticles with a uniform particle size of less than 100 nm were successfully densely immobilized onto CNFs. This is the first time that gold nanoparticles have been densely immobilized onto CNFs in contact with each other, as demonstrated in this study. Besides, immobilization amount of Au nanoparticles could be controlled. The composite films of polypropylene and Au-CNFs shows conductivity of in-plane direction in the case of the film containing 5 vol% gold.

Free Research Field

高分子

Academic Significance and Societal Importance of the Research Achievements

電子機器の飛躍的な高性能化に伴い、放熱や静電気除去、電磁遮蔽の重要性が高まっている。そのため、部材として熱及び電気伝導性樹脂が注目されているが、それらは伝導性フィラーを多量に添加して製造されているため、樹脂の強度や軽量性が損なわれている。アスペクト比の大きなフィラーほど、効率よく伝導特性を付与できることが知られているため、本研究では、表面を金ナノ粒子で被覆したセルロースナノファイバー（CNF）を調製し、樹脂フィラーへの適用を目指した。熱及び電気的特性だけでなく、特異な光学的特性や触媒能を有する金ナノ粒子をCNF表面に選択的かつ密に析出させた例は過去に報告がない。