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    Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/4030


    Title: 界面活性劑溶液濕潤疏水表面之行為;Wetting Behavior of Surfactant Solutions on Hydrophobic Surfaces: Copper and Teflon
    Authors: 洪庭旭;Ting-Syu Hong
    Contributors: 化學工程與材料工程研究所
    Keywords: 界面活性劑;接觸角;surfactant;contact angle
    Date: 2007-05-31
    Issue Date: 2009-09-21 12:28:59 (UTC+8)
    Publisher: 國立中央大學圖書館
    Abstract: 水滴濕潤(drop wetting)物質表面,決定於楊氏方程式(Young’s equation)熱力學平衡,氣-固(gas-solid)張力、固-液(solid-liquid)張力、液-氣(liquid-gas)張力,三個方向的張力維持平衡,進而在表面上液體跟固體之間表現出一個角度,此角度稱為接觸角(contact angle)。 本研究利用不同的界面活性劑(surfactant)水溶液,在銅和鐵氟龍(Teflon)這兩種不同的疏水表面,研究其水滴濕潤行為的探討,在接觸角的部分,發現無論是陽離子型(cationic)或陰離子型(anionic)的單尾鏈(one tail)界面活性劑,並不會由於疏水端碳數的增加,使其接觸角下降,而在表面張力(surface tension)方面,不管是哪一種帶電離子型的界面活性劑,也不會因疏水端的碳數增加,而造成表面張力下降的幅度特別低,但由不同尾鏈數目來比較,接觸角及表面張力都比單尾鏈的帶電離子型的界面活性劑,所表現還要低,在非離子型的界面活性劑方面,本研究發現使用擁有疏水端十二個碳數的界面活性劑和有苯環的疏水端比較,發現擁有苯環的疏水端對疏水表面有低的接觸角,而表面張力也相對的比較低。 在實驗中發現,界面活性劑在濕潤固體表面時,跟固體本身的帶電荷性質有關係,我們將濃度增加到臨界微胞濃度(Critical micelle concentration)CMC時,無論是離子型或非離子型,表面張力開始維持定值,但離子型濃度達到CMC約五倍時,又繼續下降,我們根據加入鹽類於溶液中,證明單尾鏈離子型界面活性劑,當達到高濃度時,會因靜電吸引關係使溶液中的界面活性劑相互之間的距離更為緊密,進而讓表面張力繼續下降,在接觸角方面,當濃度達到了CMC時,在疏水銅表面上,非離子型和單尾鏈陽離子型接觸角都約維持定值,但單尾鏈陰離子型達到約5倍CMC時,因表面張力的下降關係,而接觸角持續下降,在鐵氟龍表面上,只有非離子型的界面活劑,達到CMC,接觸角維持定值,而單尾鏈陰離子和陽離子型濃度到達5倍CMC時,接觸角隨表面張力下降因素,造成接觸角度下降,而雙尾鏈帶電離子界面活性劑方面,無論在疏水銅表面或鐵氟龍接觸角的水滴角濕潤現象,可能隨濃度增加在表面上因結構排列的不同,因而濕潤接觸角度跟著濃度的增加,呈現直線下降。 Drop wetting on material surface that is decided by Young’s equation. Gas-solid tension, solid-liquid tension and liquid-gas tension are balance on wetting substrate. Between liquid and solid is display a angle that the angle is call: “Contact Angle”. In the research, steady of wetting behavior of surfactant solutions on the hydrophobic surfaces: Copper and Teflon. We know that have low γsg (Cu=21.2mN/m,Teflon=6.78mN/m) and high contact angle (Cu~100°,Teflon~130°) on Cu and Teflon surfaces. Because of hydrophobic property surfaces, therefore use surfactant solutions to decrease γgl,γsl and contact angle for achieve wetting effectiveness. We find out contact angle of nonionic surfactants are not change when reach CMC, but contact angle of anionic surfactants are continue decrease when reach high CMC on Cu and Teflon surfaces. Contact angle of cationic surfactants are not change on Cu surface, but that continue decrease when reach concentration on Teflon surface. However, contact angle of two tail ionic surfactants are always continue decrease with concentration increase on Cu and Teflon surfaces.
    Appears in Collections:[化學工程與材料工程研究所] 博碩士論文

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