Development of Stable and Conductive Composition-Tuned MXenes for Multifunctional Applications
- 주제(키워드) MAX , MXene , 2D materials , Stability , High Sensitivity , Gas sensor , EMI shielding
- 발행기관 고려대학교 대학원
- 지도교수 강윤찬, 김선준
- 발행년도 2026
- 학위수여년월 2026. 2
- 학위명 박사
- 학과 및 전공 대학원 신소재공학과
- 세부전공 신소재공학전공
- 원문페이지 183 p
- 실제URI http://www.dcollection.net/handler/korea/000000306902
- UCI I804:11009-000000306902
- DOI 10.23186/korea.000000306902.11009.0300806
- 본문언어 영어
초록/요약
Two-dimensional MXenes have emerged as a highly versatile materials platform owing to their exceptional electrical conductivity, rich surface chemistry, and structural tunability, making them attractive for a wide spectrum of next-generation technologies. Yet, the practical deployment of MXenes has been fundamentally limited by challenges rooted in their chemical instability, uncontrolled interlayer organization, and compositional heterogeneity, all of which significantly degrade their reliability and restrict their integration into functional systems. This dissertation aims to overcome these intrinsic limitations by establishing a comprehensive framework for tuning MXene chemical composition, surface terminations, crystallinity, and interlayer chemistry, thereby expanding the material’s functional adaptability and enabling stable, high-performance MXene architectures. To achieve precise control over interlayer spacing and termination distribution, ionic species were systematically introduced into Ti3C2Tx MXene, allowing for the deliberate regulation of electrostatic interactions, charge transport pathways, and surface energetics. Through this approach, the inherent structure–property relationships governing MXene stability and electronic behavior were clarified, demonstrating how external ionic environments can be leveraged to stabilize MXene layers, suppress unwanted restacking, and modulate chemical reactivity. Complementary to ionic tuning, surface modification strategies were developed using conductive polymers to passivate reactive surface sites and enhance environmental durability. In particular, polymer-assisted functionalization of Mo2TiC2Tx provided a controlled means to regulate interfacial chemistry, mitigate oxidation-driven deterioration, and maintain long-term structural integrity under humid and oxidative conditions, establishing a generalizable methodology for MXene stabilization. Furthermore, synthesis routes were refined to produce high-crystalline Mo2TiC2Tx with reduced defect density and uniform chemical composition, leading to substantial improvements in oxidation resistance, moisture tolerance, and electronic homogeneity. This advancement reveals the central importance of crystallinity engineering in securing stable MXene frameworks and highlights how optimized precursor chemistry and etching pathways can determine the ultimate robustness of the material. Beyond issues of stability, the dissertation also addresses the often-overlooked challenge of MXene storage and redispersion. Ion-intercalation techniques were developed to maintain interlayer separation over extended periods, allowing aged MXenes to be uniformly redispersed without loss of conductivity or processability. This capability ensures that MXene dispersions can be stored, transported, and reprocessed on demand, offering a scalable and industrially compatible route for manufacturing application adaptive MXene materials. Collectively, these studies construct a unified strategy that integrates ion engineering, surface passivation, crystallinity enhancement, and interlayer control to systematically tailor the chemical composition and structural organization of MXenes. By elucidating the relationship between compositional tuning and macroscopic functionality, this dissertation provides fundamental insight into the design of stable, high performance MXene systems and establishes a versatile foundation for their application in advanced electronics, energy storage, electromagnetic shielding, chemical detection, and a wide array of multifunctional platforms requiring precise and durable materials engineering.
more목차
ABSTRACT ........................................................................................................................ i
국문 초록 ............................................................................................................................ iii
PREFACE ........................................................................................................................... vi
TABLE OF CONTENTS ............................................................................................................. vii
LIST OF TABLES .......................................................................................................... x
LIST OF FIGURES .......................................................................................................... xi
CHAPTER 1. INTRODUCTION ....................................................................................... 1
CHAPTER 2. THEORETICAL BACKGROUND ........................................................... 4
2.1 Structure and properties of MAX and MXene ....................................................... 4
2.2 MXene-based gas sensors: principles and performance ........................................ 6
CHAPTER 3. Ti3C2Tx MXene Nanolaminates with Ionic Additives for Enhanced Gas
Sensing Performance ........................................................................................................... 8
3.1 Introduction ........................................................................................................... 8
3.2 Experiment ........................................................................................................... 11
3.3 Results and discussion ......................................................................................... 13
3.4 Conclusion ........................................................................................................... 28
3.5 Appendix.............................................................................................................. 29
3.6 References............................................................................................................ 39
CHAPTER 4. NH3 Detection using PANI-Mo2TiC2 Composites toward Printable All
MXene Gas Sensors ........................................................................................................... 45
4.1 Introduction ......................................................................................................... 45
4.2 Experiment ........................................................................................................... 48
4.3 Results and discussion ......................................................................................... 53
4.4 Conclusion ........................................................................................................... 72
4.5 Appendix.............................................................................................................. 73
4.6 References............................................................................................................ 87
CHAPTER 5. Development of a highly-crystalline Mo2TiC2 MXene for deep-learning
assisted gas detection ......................................................................................................... 93
5.1 Introduction ......................................................................................................... 93
5.2 Experiment ........................................................................................................... 95
5.3 Results and discussion ......................................................................................... 98
5.4 Conclusion ......................................................................................................... 111
5.5 Appendix............................................................................................................ 112
5.6 References.......................................................................................................... 121
CHAPTER 6. Achieving Full Redispersion of Dried MXene Monoliths via Trace Metal
Cation Intercalation ........................................................................................................ 124
6.1 Introduction ....................................................................................................... 124
6.2 Experiment ......................................................................................................... 127
6.3 Results and discussion ....................................................................................... 130
6.4 Conclusion ......................................................................................................... 144
6.5 Appendix............................................................................................................ 145
6.6 References.......................................................................................................... 156
CHAPTER 7. CONCLUSIONS ..................................................................................... 160
RESEARCH ACCOMPLISHMENTS ...................................................................... 162
