以AOT 逆微胞系統製備有機凝膠及二氧化鈦奈米粒子之結構與性質研究

Structures and properties of organogels and TiO2 nanoparticles prepared using AOT reverse micelles

賴柏翔(Po-Hsiang Lai)

指導教授 ： 賴偉淇

淡江大學/工學院/化學工程與材料工程學系碩士班/碩士(2010年)

https://doi.org/10.6846/TKU.2010.00290

摘要

本研究分二部份，首先探討高濃度丁二酸二辛酯磺酸鈉(AOT)/油性溶劑/水 逆微胞(reverse micelles)的相行為、流變性質及結構；接著將AOT 逆微胞視為微型反應器，使四異丙氧基鈦烷(TTIP)在逆微胞水相進行反應，製備二氧化鈦奈米粒子並應用於光觸媒。
高濃度AOT 溶於正己烷，並加入水，形成逆微胞系統。改變AOT 濃度、水含量(wo 值)及不同碳數的油相溶劑，觀察系統相行為與利用流變儀、SAXS 與OM 儀器分析並探討系統的性質及結構。經由結果得知，18 m AOT〜72 m AOT(wo=2)為半透明gel-like，經由流變頻率掃描顯示為多重鬆弛模數(Multi relaxation model)，其結構為圓柱體六角最密堆積結構，然而AOT 濃度越高，圓柱體的半徑會越小，而且gel-like 的黏彈性質也越強。固定AOT 濃度為72 m，當wo=2〜6 時，結構皆為圓柱體六角最密堆積結構，而wo 值越高，圓柱體半徑就會越大，gel-like 的黏彈性質會變弱；當wo=7〜11 時，相態為透明gel-like，而多重鬆弛模數會轉換成單一鬆弛模數(Single relaxation model；Maxwell model)，結構則是圓柱體六角最密堆積和層狀的共存結構；當wo 值超過12，則會形成高黏性流體，是層狀結構。固定72 m AOT(wo=2)，改變不同碳數的油相溶劑，皆是半透明gel-like 且結構為圓柱體六角最密堆積排列，圓柱體半徑也無明顯差異，只是gel-like 的黏彈性質會改變。
四乙丙氧基鈦烷(TTIP)在AOT 逆微胞中進行水解縮合反應製備二氧化鈦奈米粒子，經過不同高溫燒結形成結晶性二氧化鈦，然後利用TGA、FTIR、XRD、BET及SEM 分析二氧化鈦的性質與結構，並且對於亞甲基藍進行光催化實驗。經由結果得知，燒結溫度800 oC 具有銳鈦礦與金紅石共存的結晶型態，而且相同燒結溫度下，wo=1 有最大比表面積，使的燒結溫度800 oC 與wo=1 的組合，具有最好的光催化性質。

關鍵字

丁二酸二辛酯磺酸鈉 ； 逆微胞 ； 小角度X 光散射儀 ； 麥斯威爾模數

並列摘要

We study the phase behavior, rheology and structure by adding water to organic solutions of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) at high concentrations. We regard the AOT reverse micelles as microreactor, and then titanium dioxide (TiO2) particles has been produced by the reaction of titanium isopropoxide (TTIP) in AOT reverse micelles and applied to photocatalyst.
High concentration AOT in hexane mixes with water to form reverse micelles. Change in AOT concentration, water content (wo value) and different number of carbon chain solvent. We observed the behavior and used rheometer, SAXS and OM analyze properies and structures. By the result, 18 m AOT〜72 m AOT(wo=2) show translucent gel-like, multi relaxation model, and hexagonally closed-packed cylindrical structure. With the increase of AOT concentrations, the radius of cylinder decrease and the viscoelastic properties of gel-like becomes strongly. As AOT concentration is a constant, wo=2〜6, the structures are hexagonally closed-packed cylindrical structure. With value of wo increasing, the radius of cylinder increases and the viscoelastic properties of gel-like becomes weakly, wo = 7〜11, show transparent gel-like, maxwell model, and the structure is coexistence of hexagonally closed-packed cylindrical and lamellae structure. The value of wo is more than 12, the gel-like is converted into a high viscosity solution, which belong lamellae structure. In different number of carbon chain solvent, we found these gel-like are translucent and the structure belonged to hexagonally closed-packed cylindrical structure. However, the radius of cylinder was no significant difference, but the viscoelastic properties were different.
TiO2 nanoparticles were prepared by hydrosis and condensation of TTIP in the AOT reverse micelles. TiO2 at different calcination temperature, their properties have been investigated by TGA, FTIR, XRD, BET and SEM. In this research, as wo=1, TiO2 have coexistence of anatase and rutile in calcination temperature at 800 oC and the largest specific surface area, so its have best photocatalytic properties.

並列關鍵字

AOT ； reverse micelle ； SAXS ； maxwell model

參考文獻

5. A. I. Oper, A. B. Holmes, Adv Mater, 11, 1270 (1999).

6. V. Arcoleo, V. T. Liveri, Chem Phys Lett, 258, 33 (1996).

7. F. J. Arriagada, K. Osseoasare, Colloid Suface A, 154, 311 (1999).

13. X. X. Zhu, K. Banana, R. Yen, Macromolecules, 30, 3031 (1997).

15. Q. Sunqing, D. Junxiu, C. Guoxu, J Colloid Interf Sci, 216, 230 (1999).