聚電解質與界面活性劑之熱力學性質探討

A Study on the Thermodynamic Properties of Interaction between Polyelectrolyte and Surfactants

顏孝耘(Hsiao-Yun Yen)

指導教授 ： 陳立仁

國立臺灣大學/工學院/化學工程學研究所/碩士(2011年)

https://doi.org/10.6342/NTU.2011.02356

摘要

本研究的第一部份是利用毛細管動黏度實驗裝置研究聚丙烯酸 (PAA) 溶液在溫度 25℃ 和 35℃ 之濃度區間，觀察不同分子量之聚丙烯酸在相同濃度下，屬於哪個濃度區間。而實驗結果發現在PAA 分子量大於25000 g/mol 時，可界定出四個黏度區間，分子量450000 與250000g/mol 圖型幾乎重疊，而隨著分子量的下降，會看到半稀釋未纏繞區間變窄。而在PAA 分子量小於5000g/mol 後溶液性質會從稀釋區間直接轉變成半稀釋纏繞區間。

第二部份利用恆溫滴定熱卡計，測得在25℃下聚電解質不同濃度的聚丙烯酸與陽離子型界面活性劑十四烷基硫磺酸鈉烷基三甲基溴化銨 (C14TAB) 形成混微胞之各個轉折濃度及焓變化。此系統一開始會因為強烈的靜電吸引力形成混微胞而造成一放熱反應，PAA 吸附達飽和後才會形成C14TAB 的自由微胞。高濃度的 PAA/C14TAB系統中則不會看到此吸附飽和與再形成自由微胞這兩階段分開的現象。

第三部份以恆溫滴定熱卡計，研究電解質聚丙烯酸與陰離子型界面活性劑十二烷基硫磺酸鈉 (SDS) 系統形成混微胞之各個轉折濃度及焓變化。在PAA 的水溶液中加入了 SDS ，會造成 PAA 的對離子凝聚效應變強，使得 PAA 鏈段上產生更多疏水的區域，而使 SDS 能順利的克服靜電斥力以疏水的方式和 PAA 形成混微胞。使PH值隨濃度上升而增加，而表面張力的測量可協助判定SDS 形成自由微胞的濃度。

第四部份以恆溫滴定熱卡計和表面張力儀，研究電解質聚丙烯酸與非離子型界面活性劑四聚乙二醇單辛醚系統形成混微胞之各個轉折濃度及焓變化，。探討25℃ 下不同濃度的聚丙烯酸，對於聚丙烯酸/四聚乙二醇單辛醚 (C8E4) 系統之影響。而顯示加入PAA 使C8E4 形成自由微胞的濃度下降，隨著C8E4 濃度上升才開始與聚丙烯酸
形成混微胞，並使溶液由透明轉為白色混濁。

關鍵字

聚電解質 ； 聚丙烯酸 ； 界面活性劑 ； 混微胞 ； 表面張力 ； 恆溫滴定熱卡計 ； 十四烷基硫磺酸鈉烷基三甲基溴化銨 ； 十二烷基硫磺酸鈉 ； 四聚乙二醇單辛醚

並列摘要

In the first part of this study, we examine the concentration regimes of poly(acrylic acid) (PAA) solution by capillary viscometer. Through the capillary viscometer, we find that under specific concentration (0.05 wt%), the solution will be in the semidilute-unentangled regime as the PAA Mw equals to 4500000 or 2500000 while it will be the dilute regime as the PAA Mw equals to 5000 or 1800.
In the second part, the interaction between anionic polyelectrolyte, poly(acrylic acid) and cationic surfactant, Tetratrimethylammonium bromide (C14TAB) has been investigated by isothermal titration calorimetry measurements. We found that in the different viscosity regime will affect the system.
In the third part, the interaction between anionic polyelectrolyte, poly(acrylic acid) and anionic surfactant, sodium dodecyl sulfate (SDS) has been investigated by isothermal titration calorimetry measurements, PH meter, and tensiometer. Poly(acrylic acid) chain becomes more hydrophobic by adding sodium dodecyl sulfate into poly(acrylic acid) solution. Then sodium dodecyl sulfate can form micelles on poly(acrylic acid) chain due to hydrophobic effect.
In the fourth part, the interaction between anionic polyelectrolyte, poly(acrylic acid) and nonionic surfactant, n-Octyltetraoxyethylene (C8E4) has been investigated by isothermal titration calorimetry measurements and tensiometer. N-Octyltetraoxyethylene can form micelles on poly(acrylic acid) chain due to hydrophobic effect.

並列關鍵字

polyelectrolyte ； PAA ； surfactants ； mixed micelle ； surfacetension ； isothermal titration calorimeter ； SDS ； C14TAB ； C8E4

參考文獻

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