Thermal functionalization of cellulose nanofibrils by phonon engineering
| Project/Area Number |
17K18837
|
|---|
| Research Category |
Grant-in-Aid for Challenging Research (Exploratory)
|
| Allocation Type | Multi-year Fund |
|---|
| Research Field |
Fluid engineering, Thermal engineering, and related fields
|
|---|
| Research Institution | The University of Tokyo |
|---|
Principal Investigator |
SHIMOI Junichiro 東京大学, 大学院工学系研究科(工学部), 教授 (40451786)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
児玉 高志 東京大学, 大学院工学系研究科(工学部), 特任准教授 (10548522)
|
|---|
| Project Period (FY) |
2017-06-30 – 2019-03-31
|
| Project Status |
Completed (Fiscal Year 2018)
|
| Budget Amount *help |
¥6,500,000 (Direct Cost: ¥5,000,000、Indirect Cost: ¥1,500,000)
Fiscal Year 2018: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
Fiscal Year 2017: ¥4,550,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥1,050,000)
|
|---|
| Keywords | セルロースナノフィブリル / 熱伝導 / フォノンエンジニアリング / 縮流効果 / 流動現象 |
|---|
| Outline of Final Research Achievements |
First, a molecular simulation of cellulose nanofibrils (CNFs) was constructed and conducted, and heat conduction of internal and interface of CNFs and the influence of surrounding molecules were clarified. Next, with the application to thermal insulation materials in mind, the thermal conductivity of the CNF aerogel was evaluated by fabricating a steady-state thermal conductivity measuring device compatible with vacuum. Furthermore, the contribution of gas heat conduction, solid heat conduction, and thermal radiation was clarified by a mesoscopic network heat transfer model, and design guidelines for improvement were identified. At the same time, with the application to high thermal conductivity materials in mind, a filament consisting of bundles of CNFs is produced by flow focusing method. Thermal conductivity is evaluated by constructing a T-junction type thermal conductivity measurement device, and the usefulness of the material was demonstrated.
|
| Academic Significance and Societal Importance of the Research Achievements |
本研究成果により，CNFの集合体としての構造を工夫することで熱輸送物性を高度に制御できる可能性が示された．これは擬一次元構造を有するCNFのフォノンエンジニアリングの研究の発展に寄与するものである．また， CNFの集合体や複合材からなるフィラメントやシート材などのバルクCNF材を利用した製品開発が進められているが，その多くが引っ張り強度やチクソ性などの機械的特性を利用したものである．CNF技術を森林産業の育成や低炭素社会の実現に繋げるためには，CNF材料の機能の多岐化および高付加価値化が必要となることを考えると，CNFの断熱材や熱伝導材としての高い潜在能力が示されたことは意義深いと思われる．
|
Report
(3 results)
Research Products
(5 results)
