奈米金粒子於油水界面自組成之研究

Colloidal Au Nanoparticle Self-Assembly from Oil/Water Interfaces

林恩慈(En-Tzu Lin)

指導教授 ： 許經夌

中原大學/理學院/物理研究所/碩士(2010年)

https://doi.org/10.6840/cycu201000996

摘要

本論文主要探討界面活化溶液─乙醇，對於水相奈米金粒子反應
至油水界面自組成的影響。在此藉由加入可降低溶液界面張力，且能降低奈米金粒子表面電荷的乙醇，因乙醇在膠體金溶液中，傾向在溶液界面保持較高濃度，且當其與奈米金粒子接觸，會改變粒子外部之檸檬酸根離子分布，降低金粒子整體的表面電荷，使粒子具有類似界面活性劑的性質，因而能夠同時將粒子反應至油水界面自組形成奈米金粒子薄膜。
本實驗以UV-Vis 光譜儀分析改變乙醇溶液比例，膠體金溶液於
反應後的透光率變化，推估奈米金粒子反應至油水界面的數量。發現當乙醇比例提高，穿透光強度亦有增強的趨勢，顯示奈米金粒子轉移至界面的幅度有增高的行情，故推測乙醇對於奈米金粒子反應至界面的程度具有一定影響力。此外， 本實驗亦藉由Dynamic Light Scattering(DLS)、UV-Vis 光譜儀、Atomic Force Microscopy(AFM)、
Scanning Electron Microscopy(SEM)驗證奈米金粒子的大小與成膜後之表面形貌。其中，奈米金粒子的排列呈現幾近單層結構的形貌，且粒子間呈現線性的連結方式。而經接觸角量測儀分析的結果，推測奈米金薄膜上層附著部分油相溶液，造成此薄膜的疏水性提高，導致接觸角大於一般奈米金粒子薄膜的接觸角度。

關鍵字

自組成

並列摘要

Self-assembly of Au nanoparticles from water phase to oil/water interface is caused by adding ethanol into oil/water system, which reduce not only the surface tension of oil/water interface but the surface charge of Au nanoparticles. In our assumption, some parts of radicals of citrate
acid around Au nanoparticles would replaced by ethanol, so that the Au nanoparticles could emerge to oil/water interface with ethanol, which
tend to keep higher concentration at interface of colloid Au solution. This phenomenon was discussed by measuring the change of transmission intensity before and after the addition of ethanol by UV-Vis spectroscopy, and we found that the transmission intensity enhanced with increasing the volume percentage of ethanol in colloid Au solution.
Besides, we also examined the particle size of original colloid Au solution by Dynamic Light Scattering(DLS), and analyzed the structures of Au nanoparticle film by Atomic Force Microscopy(AFM)and Scanning Electron Microscopy(SEM). We found that the particle size would not change after react, and the self-assembly of Au nanoparticles seems likely linear aggregation. On the other hand, we know that the Au nanoparticle films were covered with some oil phase solution because the contact angle of films were so large.

並列關鍵字

self-assembly

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