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Effect of Nanoscopic Curvature from Anodic Aluminum Oxide on Physical Structuring of Organic and Inorganic Materials and Its Applications : 양극 산화 알루미늄의 나노굴곡 표면구조가 유·무기 재료의 물리적 구조에 미치는 영향 및 응용에 관한 연구

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dc.contributor.advisor차국헌-
dc.contributor.author유귀덕-
dc.date.accessioned2017-07-13T08:33:59Z-
dc.date.available2017-07-13T08:33:59Z-
dc.date.issued2013-02-
dc.identifier.other000000009673-
dc.identifier.urihttps://hdl.handle.net/10371/119660-
dc.description학위논문 (박사)-- 서울대학교 대학원 : 화학생물공학부, 2013. 2. 차국헌.-
dc.description.abstractNanostructures have been received considerable interests, since they have exhibited unique properties that are not the same as that in bulk or in molecular level. Many investigations have proved that their physiochemical properties greatly depend on the size, hardness of confinement, surface curvature, and anisotropy/asymmetry of nanostructures. This interesting behavior has suggested creation of more advanced materials which properties are tailored based on the structural parameters.
In this thesis, we introduced another new structural parameter and investigated its effect on materials properties and it applicability as well. Utilizing self-assembled anodic aluminum oxide, we obtained hexagonally packed mesoscopic concave patterns. A replication technique enabled us to produce both concave and convex patterns accompanied with packing transition. Hence, our system incorporated pattern curvature and packing structure simultaneously. . On the basis of the interesting structural parameter, we exhibited the importance of our finding to control the physical structuring of organic and inorganic materials.
Firstly, coating polymer thin films on concavely and convexly patterned Al substrates, we studied how the structure influenced the thin film stabilities. Even though the polymer films are inherently unstable on the substrate material, the polymer thin films on the concave patterns were found to present wetting behavior whereas those on the convex patterns exhibited extensive rupturing. We ascribed the behavior to the opposition in topological gradient in each pattern. Thus, it was recognized that pattern curvature can be an important parameter to enhance film stability.
Secondly, we investigated thin film stabilities on concavely patterned and convexly patterned PI substrate whereby the coated polymer films are originally stable on the substrate. In spite of its inherent stability, polymer thin films were found to dewet on the convex patterns by hole nucleation at the peaks of the patterns. Although dewetting was initiated by the local process, dewetting on the convex patterns presented long-range-order rupturing morphologies. We speculate that the long range correlation came from pattern-directed dewetting on the regularly packed patterns and its subsequent amplification likewise amplification of capillary wave in spinodal dewetting.
Thirdly, we exploited the inverse packing characteristics of the two patterns and investigated its effect on pore growth in anodization. Anodizization of the concavely patterned Al produced typical circular pores in hexagonal packing. Anodization of the inversely patterned Al formed triangular pores in inverse-hexagonal packing. Thus, we discovered that both circular and triangular pore shapes are achievable from the self-assembled structure of AAO itself without any assistance of expensive lithographic techniques. The opposition in pit packing structures and the topographies around the pits were discussed to regulate the pore shape.
Lastly, by incorporating pattern-directed dewetting phenomena, we controlled the topographies of the peaks in the patterns and investigated its alteration on pore formation in anodization. Reducing the curvature and depth of the convex patterns, triangular pores were found to become more isotropic, accompanying formation of subsidiary pores in the regions other than pits. In addition, the regulation in pattern topographies allowed us to obtain pore arrays with the same ordering structure even from the oppositely packed patterns. Therefore, we found that pattern topography as well as pit order structure is an important parameter to control the pore shape and its ordering.
In conclusion, we find importance of the structure incorporating curvature and packing to control physical structuring of materials. As a new finding of structural parameter in nanomaterials has created advanced materials of better tailored properties, our finding of a new structural parameter and investigation through its utilization will suggest a new strategy to control nanomaterials.
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dc.description.tableofcontentsAbstract i
List of Tables vii
List of Figures viii

Chapter 1. Introduction 1
1.1 Nanoscopic confinement on materials 1
1.2 Film stability on flat or patterned substrate 5
1.3 Pore growth during anodization with or without pre-patterns 7
1.4 References 10


Chapter 2. Pattern Curvature to Control Thin Film Stability on Non-wettable Substrates 14
2.1 Introduction 14
2.2 Experimental 17
2.3 Results and Discussions 22
2.3.1 Stability of PS films on flat Al substrates 22
2.3.2 Stability of PS films based on pattern curvature upon thermal annealing 31
2.3.3 Stability of PS films based on pattern curvature upon mechanical stress 53
2.4 Conclusion 56
2.5 References 58

Chapter 3. Pattern Curvature to Control Thin Film Stability on Wettable Substrates 62
3.1 Introduction 62
3.2 Experimental 64
3.3 Results and Discussions 70
3.3.1 Stability of PS films on flat PI substrates 70
3.3.2 Stability of PS films based on pattern curvature upon thermal annealing 76
3.3.3 Stability of PS films based on pattern curvature upon mechanical stress 97
3.4 Conclusion 101
3.5 References 103


Chapter 4. Curvature of Pre-patterns on Pore Growth in Anodization of Aluminum 107
4.1 Introduction 107
4.2 Experimental 110
4.3 Results and Discussions 115
4.3.1 Curvature sign of pre-patterns on pore shape and its ordering 115
4.3.2 Growth mechanism for triangular pores 130
4.3.3 Triangular pores assisted by microsphere assembly 141
4.4 Conclusion 146
4.5 References 148

Chapter 5. Topography Control of Pre-patterns on Pore Grwoth in Anodization of Aluminum 151
5.1 Introduction 151
5.2 Experimental 154
5.3 Results and Discussions 159
5.3.1 Applied voltage or current on pore growth on convexly patterned Al 159
5.3.2 Pattern topography on pore initiation on convexly patterned Al 166
5.3.3 Pattern curvature on pore shape and its ordering 175
5.4 Conclusion 183
5.5 References 185
국문초록 187
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dc.formatapplication/pdf-
dc.format.extent11385046 bytes-
dc.format.mediumapplication/pdf-
dc.language.isoen-
dc.publisher서울대학교 대학원-
dc.subject.ddc660-
dc.titleEffect of Nanoscopic Curvature from Anodic Aluminum Oxide on Physical Structuring of Organic and Inorganic Materials and Its Applications-
dc.title.alternative양극 산화 알루미늄의 나노굴곡 표면구조가 유·무기 재료의 물리적 구조에 미치는 영향 및 응용에 관한 연구-
dc.typeThesis-
dc.description.degreeDoctor-
dc.citation.pagesxvii, 189-
dc.contributor.affiliation공과대학 화학생물공학부-
dc.date.awarded2013-02-
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