研究生: |
張簡上煜 |
---|---|
論文名稱: |
應用液膜固化技術觀測凱爾文-荷姆霍茲不穩定性動態產生之奈米液珠 Visualization of Nano Droplets Formed by Kelvin-Helmholtz Instability Using Liquid Film Curing Technique |
指導教授: | 曾繁根 |
口試委員: | |
學位類別: |
碩士 Master |
系所名稱: |
工學院 - 奈米工程與微系統研究所 Institute of NanoEngineering and MicroSystems |
論文出版年: | 2008 |
畢業學年度: | 96 |
語文別: | 中文 |
論文頁數: | 84 |
中文關鍵詞: | 液膜固化 、凱爾文-荷姆霍茲不穩定性 、奈米液珠 |
相關次數: | 點閱:59 下載:0 |
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本實驗主要利用微機電製程技術來製作微流道裝置,並以該元件
配合流體的操控,改變不同的流體速度及流體性質來進行測試,利用
兩不相溶流體界面間的凱爾文-荷姆霍茲不穩定性,成功地產生了直
徑大小在奈米等級的液珠。
為了瞭解奈米液珠產生的機制,本實驗利用固化液膜之技術,將
凱爾文-荷姆霍茲不穩定性的動態過程固化,固化液膜的樣貌證實了
連續相流體和分散相流體界面間凱爾文-荷姆霍茲不穩定性的確存在,且因此導致液膜最終破碎而形成奈米液珠。
定量分析不同流率下所產生的液珠尺寸,發現不同流體速度產生
的平均液珠尺寸差異不大,且液珠尺寸分布的峰值相同,這是因為在
奈米尺度下,表面張力效應才是影響液珠尺寸的主要因素,而在利用
添加不同比例界面活性劑以改變兩相流體的界面張力值的實驗中,
也證實了此一觀點,界面活性劑添加量過少時,兩相流體界面以及所
產生的液珠界面容易不穩定,因此分散相液膜容易破碎形成奈米液
珠,但此等小液珠也容易合併在一起形成較大尺寸的液珠,當界面活
性劑的量到達一定值,兩相流體界面一旦能夠穩定,較大尺寸的液珠
數量將銳減,且此時再加入更多的界面活性劑也對所產生的液珠大小
影響不大。
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