Fabrication of Zeolite Imidazolate Framework 8 (ZIF-8) granule for Functional surface applications
- 주제(키워드) ZIF-8 , Functional surface , Catalyst , Self-Stratified , Water harvesting
- 발행기관 고려대학교 대학원
- 지도교수 강윤찬
- 발행년도 2023
- 학위수여년월 2023. 2
- 학위명 석사
- 학과 및 전공 대학원 신소재공학과
- 세부분야 해당없음
- 원문페이지 103 p
- 실제URI http://www.dcollection.net/handler/korea/000000270116
- UCI I804:11009-000000270116
- DOI 10.23186/korea.000000270116.11009.0001426
- 본문언어 영어
초록/요약
Metal-organic frameworks (MOFs), a new class of porous crystalline materials, have attracted significant interest for potential applications in gas separation, storage, and catalysis. The application of zeolitic imidazolate framework-8 (ZIF-8), a versatile MOF based on imidazolate ligands, is hindered by its structure. The microporous ZIF-8 structure has a negative effect on diffusion and mass transfer, which can lead to a low diffusion rate of reactants larger than 2 nm. In chapter 2, the concept of a super structured hierarchical porous ZIF-8 (HPZIF-8) micro-particle has been presented to overcome these limitations, which consists of two different pore structures (micropore and mesopore). We propose a simple aggregation method to enhance the controllability and performance of ZIF-8 in a water-based environment. Compared with the same-sized ZIF-8 particles, the HPZIF-8 particles can reach a higher mass transfer through the mesopores and lead to high diffusion rates. To demonstrate the performance enhancement, the fabricated HPZIF-8 was characterized as a photocatalyst for removing methylene blue from water. The two different pore structures of HPZIF-8 resulted in improved catalytic performance. These results could inspire MOFs research for applications such as carbon dioxide capture and catalysis. With this hierarchical ZIF-8 structure, we have characterized homogeneous water-repelling micro/nanoporous structures that resemble the surface of lotus leaves. The wettability of the surface of a material is determined by the surface energy, but if the microstructure of the surface is controlled to a complex micro- and nano-level structure, the wettability is extremely reduced and the surface contact angle with water is 150° or more. With this principle, we generated the patterned arrays with different wetting properties using chemical functions between the polymers and the particles. In chapter 3, the fabrication of a self-stratified superhydrophobic/hydrophilic hybrid surface on 3D structures using HPZIF-8 was investigated. The availability of patterned surfaces with superhydrophobic and hydrophilic regions will greatly enhance the utility and functionality of the devices. Since the patterned surfaces in nature are typically three-dimensionally curved, such as the banana leaf and Namib desert beetle. Due to that, 3D printing is considered to be the best option to design complex 3D structures. The versatility of 3D printing methods can help overcome the challenges of creating patterned surfaces by reducing cost, the number of steps, and the need for coatings. Using 3D printing, we fabricated the self-patterned surface through self-stratified two different affinity 3D printed polymer materials. Then, we applied structural water harvesting using a patterned hybrid surface. The synergistic effect of patterned structures, the surface properties (roughness and wettability gradient), and the structural geometry, make the formation of the water droplet and water droplet transport during water collecting processes. This conceptual idea can provide a solution to the scarce water problem and water crisis.
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ABSTRACT ⅰ
국문 초록 ⅳ
TABLE OF CONTENTS ⅶ
LIST OF TABLES ⅸ
LIST OF FIGURES ⅹ
CHAPTER 1. 1p
1.1 Background 1p
1.1.1 Metal-organic frameworks (MOFs) 1p
1.1.2 ZIF-8 2p
1.1.3 Hierarchical structure with functional surface previous literature 4p
1.1.4 3D printing 7p
1.1.5 Water harvesting 8p
1.2 Motivation 10p
1.3 Outline 11p
Figure sets 13p
CHAPTER 2. 17p
2.1 Introduction 17p
2.2 Experimental section 21p
2.2.1 Materials 21p
2.2.2 Synthesis of Micro-sized ZIF-8 (mZIF-8) 21p
2.2.3 Synthesis of Nano-sized ZIF-8 (nZIF-8) 21p
2.2.4 Synthesis of Hierarchical porous ZIF-8 (HPZIF-8) 22p
2.2.5 Photocatalytic analysis 22p
2.3 Results and discussion 24p
2.4 Conclusion 34p
Figure sets 35p
CHAPTER 3. 39p
3.1 Introduction 39p
3.2 Experimental section 43p
3.2.1 Fabrication of patterned surface 43p
3.2.2 Characterization method 44p
3.2.3 Water harvesting measurement 45p
3.3 Results and discussion 46p
3.4 Conclusion 62p
Figure sets 63p
CHAPTER 4. 69p
Reference 71p
