為了適應營養貧瘠的環境，食蟲植物演化出具特殊功能的葉子來獲取養分，豬籠草的捕蟲籠同時扮演了吸引、捕捉以及儲存獵物的功能，位於捕蟲籠上方的唇可在潮濕的環境下啟動捕食機制，山脊般的多階層結構提升其超親水性並產生異向性的表面潤濕性。本研究著重於探討豬籠草的捕蟲籠唇表面結構以及濕潤性質，在固定的溫度與濕度範圍內，比較以三種方式處理 (新鮮、臨界點乾燥處理及鍍覆糖漿)的豬籠草唇潤濕效果。此外，為瞭解微結構的影響，我們以簡單的翻模方法得到仿豬籠草唇表面的兩種高分子材料(PDMS和 NOA 63)，可以保存表面多階層結構並呈現接近超疏水性質(接觸角約140)，相互平行的溝脊結構也使其具有異向性潤濕的特性。以此具有相同結構的高分子材料為基板，進而利用表面改質以及修飾的方式改變其表面性質。首先，結合溶膠凝膠及噴霧塗佈法使小尺寸的粒子附著在高分子基板上，產生多階層結構，獲得兼具高疏水性以及抗沾水性質的表面。另一方面，大氣電漿則用來在基板表面產生氫氧基，得到暫時性的親水性表面，結果顯示NOA 63的親水時效性較PDMS久。未來可將此特殊結構應用在不同的製程及材料上，製作出具多功能表面特性的新穎仿生材料。

Carnivorous plants have evolved leaves into unique functions to adapt infertile environments. Genus Nepenthes has pitcher for attracting and retaining the prey. Peristome, a rim that surrounded on the top of pitcher, is a trap activated in wet and moist conditions. Ridge-like hierarchical structure of peristome surface enhances the superhydrophilicity and results in anisotropic wetting. This research focused on the microstructure and wettability of peristome. Wetting efficiency of peristome was measured under 3 conditions (fresh, critical point dryer-treated and sucrose-coated) under controlled temperature and relative humidity to elucidate the wetting mechanism. In order to understand the effect of microstructure of peristome on the wetting properties, two kinds of polymer, PDMS and NOA 63, were used to mimic the surface of peristome via replication method. The replicas not only well preserve the original structure but exhibit nearly superhydrophobicity (contact angle ~140) and anisotropic wettability due to the parallel ridges on the surface. Surface modifications were further employed on the surface to adjust the surface properties. Spray coating and sol-gel methods were utilized to deposit smaller PDMS-TEOS cross-linked particles on replica and form hierarchical structures, exhibiting both superhydrophobicity and water-repellency. On the other hand, atmospheric pressure plasma was applied to generate hydroxyl groups on the surface, leading to temporarily hydrophilic surface. The hydrophobic recovery time of NOA 63 was longer than that of PDMS. Results indicate that the unique microstructure of peristome can be utilized in various processes and materials to synthesize novel bio-inspired materials with multifunctional surface properties.

List of Tables V
Figure Caption VI
1 Introduction 1
2 Literature Review 4
2.1 Wetting 4
2.1.1 Theory of Superhydrophobicity 4
2.1.2 Anisotropic Wetting 5
2.1.3 Wetting Transition for Hydrophilic Materials 7
2.1.4 Superhydrophobic Plant Surfaces 8
2.2 Surface Properties and Capture Mechanisms of Nepenthes 19
2.3 Synthesis of Superhydrophobic Surfaces 23
2.3.1 Replication Method 23
2.3.2 Spray Coating Method 24
2.4 Surface Modifications 31
3 Experimental Methods 34
3.1 Sample Preparation of Waxy Zone and Digestive Zone 34
3.2 Wetting Efficiency Measurement of Peristome 34
3.2.1 Sample Preparation 34
3.2.2 Wetting Efficiency Measurement 36
3.3 Replication Process 41
3.3.1 Synthesis of Negative Mold 41
3.3.2 Synthesis of Positive Mold 41
3.4 Spray Coating Process 44
3.5 Atmospheric Pressure Plasma Treatment 44
3.6 Structural Characterization 45
3.6.1 Optical Microscopy 45
3.6.2 Scanning Electron Microscopy 45
3.6.3 Contact Angle Measurement 46
4 Results and Discussions 48
4.1 Waxy Zone and Digestive Zone 48
4.1.1 Surface Morphology and Microstructure 48
4.1.2 Wetting Property 49
4.2 Surface Properties of Peristome 52
4.2.1 Surface Morphology and Microstructure 52
4.2.2 Wetting Efficiency Measurement 53
4.2.3 The Importance of Microstructure 54
4.2.4 The Importance of Hydroxyl Group 55
4.3 Replication 61
4.3.1 Microstructure Characterization 61
4.3.2 Contact Angle Measurement 61
4.3.3 Wetting Transition 63
4.4 Spray Coating 68
4.4.1 Microstructure Characterization 68
4.4.2 Wettability 69
4.4.3 Water-repellency 70
4.5 Surface Modification by Atmospheric Plasma Treatment 76
4.5.1 Wettability and Hydrophobicity Recovery 76
4.5.2 The Effect of Injected Gases 77
4.5.3 The Role of Hierarchical Structure 77
5 Conclusions 81
6 Future work 84
6.1 Calculation of Theoretical Contact Angle 84
6.2 Selection of hydrophilic materials 85
6.3 Lithographic Fabrication 85
6.4 Modification of Spray Coating Procedure 86
6.5 Synthesis of Hydrophobic/Hydrophilic Hybrid Surfaces 86
References 88

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