Revisiting Graphitization process: effects of organic template on carbon material designing

2020 Fiscal Year Final Research Report

• Project/Area Number: 19K23572
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0401:Materials engineering, chemical engineering, and related fields
• Research Institution: Shinshu University
• Principal Investigator: Fujisawa Kazunori 信州大学, 先鋭領域融合研究群先鋭材料研究所, 助教(特定雇用) (00724634)
• Project Period (FY): 2019-08-30 – 2021-03-31
• Keywords: 炭素化 / 黒鉛化 / 活性炭 / 高温熱処理

Outline of Final Research Achievements

The carbonization and graphitization process of organic materials was revisited. A directly annealable platform was prepared out of a graphite sheet. Short pulse laser microfabrication helped to create graphite grids. Cellulose was chosen as a representative "hard carbon" precursor, and then nanofibrous cellulose in gel form was drop-coated over a graphite TEM grid. Cellulose thin-film covering graphite grid was sequentially annealed at high temperature ranged from 1200oC up to 3000oC. By annealing cellulose, bubble-like cells with disordered carbon shells were formed in the thin-film at first. As increasing annealing temperature, small cells were merged, and the carbon shells were thickened. In the case of thin-film, cellulose-derived carbon showed an unexpected highly crystalline feature after annealing over 2400oC. This indicated that the spatial arrangement of cells with carbon shells determines the final carbon/graphite structure.

Free Research Field

炭素材料

Academic Significance and Societal Importance of the Research Achievements

炭素材料は日常生活で広く利用されているが，有機物の熱処理によって生じる炭素の構造は予測ができない．そこで構造や組成が均質でない有機物の炭素化過程について構造の定点観察による解明を試みた．セルロースに由来する炭素では，加熱に伴って生じる炭素殻を持つ泡様のセルの配置が炭素・黒鉛の構造を決定していることが分かった．そしてセルが平面に並んでいる状態では，従来の活性炭様の構造でなくグラフェン様の結晶性の高い黒鉛が生じることがわかった．この炭素化・黒鉛化過程に関わる新知見を用いることにより，他の有機物からの炭素調製における構造予測または制御が可能になると考えられ，有機残渣の有効利用に貢献する．