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Title: | 運用二維分子層調控於表面可濕性操控之研究 Finely Tunable Surface Wettability by Two-Dimensional Molecular Manipulation |
Authors: | Hsiang-Hua Li 李香樺 |
Advisor: | 廖尉斯(Wei-Ssu Liao) |
Keyword: | 化學拔除法,自主裝單分子層,表面可濕性, chemical lift-off lithography,self-assembled monolayers,surface wettability, |
Publication Year : | 2018 |
Degree: | 碩士 |
Abstract: | 整體材料介面的性質決定於表面分子層的分子環境,尤其是在大面積基材中特定性質的表現與表面的功能性展現;而藉由表面化學的多樣化,材料最表層的特性便可以透過多種不同的方法改變或給予特定的功能性。儘管目前的技術可以提供有效的材料表面性質修飾,但由於在表面單分子層的二維空間分佈及其組成的控制上仍具有挑戰,使得製作組成均勻且於空間上可調節表面分子環境的方法仍然十分有限。由於巨觀下的材料性質仰賴微觀中表層分子的組成,因此掌握精準調節分子層的技術對於控制基材的呈現性質特別重要。在本篇論文中,我們利用化學拔除法來調控基材表面單分子層的分子環境;利用活化的印章與表面分子的接觸化學反應,使部分的表面分子隨印章脫離表面而被拔除,製造出分布均勻的分子層人造缺陷。接著再利用回填插入的方式,將具有相異功能的分子修飾於先前被拔除的表面區域,因而可達到在特定位置調控分子層的組成,進一步改變基材的呈現性質。以表面潤濕性的調節為例,應用化學拔除法先行圖案化表面基材的親水性羥基硫醇單分子層,緊接著填入末端含氟的硫醇分子於先前被拔除的區域,便可製造出乘載不同表面親疏水性質的不同區域。後續在進行不連續去濕的過程中,藉由兩個表面區域間明顯的性質差異,便可使液體流經基材表面時殘留於親水區域,最終形成單一分離的微液珠。藉由此法,我們的基材不僅對於水溶液,連低表面張力的有機液體都可以在由化學拔除法調控產生的分子層結構上產生微液珠陣列。為提高此研究的實用性,我們進一步應用這些微液珠陣列去引導溶液中所帶材料於此種表面上之排列行為,以製備有效的分析乘載平台。例如,引導具酸鹼值感測功能的微粒子在不連續去濕過程中排列成二維感測器陣列,以作為高通量檢測的偵檢平台。此外,藉由此法可簡易控制液珠大小的特性,讓基質輔助雷射脫附/電離質譜法中分析物與基質的共結晶步驟發生區域小於檢測時所用激發雷射光點之尺寸,避免傳統操作方法中之咖啡環效應,以有效改善此類技術於偵測時的訊號不穩定性,並大幅提升分析定量的精確度。藉由這些實驗結果可知,利用化學拔除法於二維空間上操控表面分子的分布與組成可控制及調整材料表面的呈現性質;而進一步藉由不連續去濕過程所產生的微液滴陣列除能提供大量的統計信號輸出,並可大幅減小數據的相對標準偏差,成功拓展表面分子層控制技術的應用性。 Local molecular environment governs material interface properties, especially in large area substrate exposing behavior and functionality expression. Diverse capability of surface chemistry can modulate material top-layer characteristics and alter or deliver specific functionalities with various approaches. Although current techniques can provide efficient surface property modification, strategies giving homogeneous and finely tunable molecular environment are still limited due to challenges in molecule spatial distribution and composition controls. This management is especially important on adjusting substrate properties, since macro scale material behavior relies on the averaged top-layer composition. In this report, Au-thiolate rupturing operation in chemical lift-off lithography (CLL) is used to manipulate substrate interface molecular environment. Creation of randomly distributed artificial self-assembled monolayer (SAM) defects generates vacancies for substrate property modification through back-insertion of molecules with opposite functionalities. Surface wettability adjustment is utilized as the example, where well-controllable molecule distribution provides finely tunable substrate hydrophobicity toward different liquids. Integration of well-defined molecular patterns supported by CLL operation, rigid boundaries composed of spatially patterned hydroxyl-terminated alkanethiols next to fluorinated molecules are created. The distinct property difference between two surface regions assist microdroplets formation when liquids flow through, where not only water solution but also low-surface-tension organic liquids, such as ethanol, isopropanol, and tetrahydrofuran can all produce isolated droplets. These microdroplet arrays can be used as a template to guide material assembly in the formation process. For example, functional microparticle can be concentrated within specific areas on a substrate and act as pH sensitive platforms for high-throughput detection. Furthermore, the finely tunable property of molecular patterns in this approach can help to overcome coffee ring effect induced reproducibility problems in matrix-assisted laser desorption/ionization mass spectrometry by creating smaller sample/matrix crystallization occasion size than the excitation laser spot. The large area repeating signal output units and associating reduced data standard deviations confirm the practical usage of these microdroplet arrays. Two-dimensional molecular manipulation provided by Au-thiolate removal in CLL operation therefore withholds capability toward homogeneous material property controls and exhibiting behavior adjustments. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/77567 |
DOI: | 10.6342/NTU201802583 |
Fulltext Rights: | 未授權 |
Appears in Collections: | 化學系 |
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ntu-107-R05223147-1.pdf Restricted Access | 2.12 MB | Adobe PDF |
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