Nanosized boron nitride-incorporated polyvinyl alcohol composites with TEMPO-oxidized cellulose nanofibers as ultrathin thermal interface materials
- 주제(키워드) thermal conductivity , nanosized boron nitride , polyvinyl alcohol composite film , filler orientation , heat dissipation
- 발행기관 고려대학교 대학원
- 지도교수 최원준
- 발행년도 2025
- 학위수여년월 2025. 2
- 학위명 석사
- 학과 및 전공 대학원 기계공학과
- 원문페이지 61 p
- 실제URI http://www.dcollection.net/handler/korea/000000291568
- UCI I804:11009-000000291568
- DOI 10.23186/korea.000000291568.11009.0001892
- 본문언어 영어
초록/요약
In this thesis, we address the critical need for effective thermal management in miniaturized and densely packed electronic devices through the development of advaced thermal interface materials (TIMs). Chapter 1 investigates the fundamental principles governing thermal conductivity and mechanical properties of polymer-based TIMs, emphasizing the importance of filler dispersion, interfacial adhesion, and matrix reinforcement. Building upon this foundation, Chapter 2 focuses on the fabrication of nanosized boron nitride (BN) and TEMPO-oxidized cellulose nanofibers (T-CNFs) reinforced polyvinyl alcohol (PVA) composites. Nanosized BN nanoparticles with an average thickness of 3.8–4.0 nm and a lateral size of 90–100 nm, were synthesized with a yield exceeding 80% through a chemical treatment of hexagonal BN with NaOH followed by ball milling. To enhance the mechanical properties of a PVA-based matrix, TEMPO-oxidized cellulose nanofibers (T-CNFs) were incorporated. The BN particles were functionalized with OH– groups to ensure good dispersion in the PVA solution, resulting in ultrathin composite films (~50 µm) made of BN/PVA/T-CNF. Although it was anticipated that the nanosized BN would lead to low thermal conductivity due to surface defects and high contact resistance, the composite films containing 50 wt% nanosized BN exhibited surprisingly high in-plane and through-plane thermal conductivities of 11.13 and 1.22 W/mK, respectively. A comparative analysis based on the Lewis–Nielsen model suggested that the size, shape, and agglomeration state of the BN particles significantly impacted the thermal conductivity of the composite films. Additionally, practical heat dissipation experiments demonstrated the excellent thermal performance and stability of the BN/PVA/T-CNF films as thermal interface materials (TIMs). By integrating experimental findings from both chapters, this thesis provides a comprehensive understanding of the design and optimization of TIMs for next-generation electronic applications. The outcomes of this research not only offer valuable insights into the rational design of BN-based composites materials but also lay the groundwork for future advancements in thermal management technologies.
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TABLE OF CONTENTS
ABSTRACT i
국문 초록 iii
PREFACE vi
ACKNOWLEDGMENTS vii
TABLE OF CONTENTS viii
LIST OF TABLES x
LIST OF FIGURES xi
CHAPTER 1. INTRODUCTION 1
1.1 Thermal Interface Materials (TIM) 1
1.2 Factors affecting the thermal conductivity of polymer-based TIM 7
1.2.1 Thermal conductive filler; loadings, shapes, size, hybridization 7
1.2.2 The properties of polymer matrix; crystallization, orientation 8
1.2.3 The control of filler microstructure; orientation, networking 9
1.2.4 The thermal interfacial resistance; functionalization 9
1.3 Objectives and goals 11
CHAPTER 2. NANOSIZED BORON NITRIDE COMPOSITE 15
2.1 Nanosized boron nitride-incorporated polyvinyl alcohol composites with TEMPO-oxidized cellulose nanofibers as ultrathin thermal interface materials 15
2.1.1 Introduction 15
2.1.2 Experiment 18
2.1.3 Results and discussion 21
CHAPTER 3. DISCUSSION 39
CHAPTER 4. CONCLUSIONS 41
REFERENCES 43
