期刊論文

標題 New Phases Found in Reverse Micelle Systems with High Concentrations of AOT
學年 102
學期 1
出版(發表)日期 2013/08/01
作品名稱 New Phases Found in Reverse Micelle Systems with High Concentrations of AOT
作品名稱(其他語言)
著者 Lai, Wei-Chi; Lai, Po-Hsiang
單位 淡江大學化學工程與材料工程學系
出版者 Washington: American Chemical Society
著錄名稱、卷期、頁數 The Journal of Physical Chemistry B 117(32), pp.9568-9575
摘要 This paper discusses the phase behavior, rheology, and structure of self-assembled sodium bis(2-ethylhexyl) sulfosuccinate (AOT) reverse micelle systems at high AOT concentrations. When the amount of AOT and wo (the molar ratio of water to AOT) were changed, many different phases were found, a fact which is not discussed in the literature. Opaque gel-like phase (phase separation) occurred with high concentrations of AOT in organic solvents without water. When the AOT concentration and wo were increased to 18–72 m and 2, respectively, the samples were gel-like and translucent. Dynamic rheological results indicate that the viscoelastic transition agreed with a multirelaxation time model. Small-angle X-ray scattering (SAXS) results imply that these samples showed a hexagonally close-packed cylindrical structure in which the diameter of a cylinder was 2.5–3.0 nm, depending on the water contents. Moreover, these AOT cylinders self-assembled into fiber bundles with a diameter of 1–10 μm, as determined using a polarized optical microscope. As wo was increased to 2–6 in 72 m AOT samples, similar rheological and SAXS results were obtained. However, a different type of viscoelastic transition occurred, from multirelaxation to single-relaxation, when wo was increased to 7–11. The samples were in the transparent gel-like phase, and the structures determined by SAXS were a combination of hexagonally packed cylindrical and lamellar structure. The close-packed cylindrical structures had larger radii and shorter lengths with increasing wo. Furthermore, when wo was increased to 12, the gel-like phase disappeared and a highly viscous solution was observed. This is because all the cylindrical structures collapsed and transformed into lamellar structures when the amount of water was further increased.
關鍵字
語言 英文(美國)
ISSN 1520-6106;1520-5207
期刊性質 國外
收錄於 SCI;EI;
產學合作
通訊作者 Lai, Wei-Chi
審稿制度
國別 美國
公開徵稿
出版型式 ,電子版,紙本