Control of Nanoscale Structures of Amphiphilic Self-Assembly by Physical Factors

物理因素对两亲性自组装纳米结构的控制

基本信息

批准号：
12440200
负责人：
MAEDA Hiroshi
金额：
$ 9.41万
依托单位：
KYUSHU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2002
项目状态：
已结题

项目摘要

(1) Reversible micelle - vesicle transition by changing pH.On protonation of oleyldimethylamine oxides to the degree of 0.5 (the half protonated state), vesicles are formed spontaneously from long fibrous micelles and this change occurs reversibly by changing the pH of the medium. The viscoelastic behavior changes from the Maxwell type characteristic to entangled network of long fibrous micelles to the gel like behavior. The conversion is rather fast and it seems to take place within 2 hours. It takes much longer time (about 14 days), however, for the viscoelastic properties of the vesicle suspension to recover to approximately the same level. The conversion most likely proceeds not in a transition like but in a continuous way.(2) Change of the structures of the films of tetradecyldimethylamine oxides (C14DMAO) at solid/solution interface.2-1. Mica/solution interfaces, hemimicelles or cylinders are formed at nonionic state while bilayers are formed at half- and full-protonated states.2-2. Graphite/solution interfaces. Hemimicelles are formed irrespective of the degrees of protonation.(3) Lamella and vesicle formation of C14DMAO by naphthalene sulfonate (NphS) counterions. This result is not trivial because most surfactant cations with a C16 tail form long fibrous micelles (the packing parameter p close to 0.5). In this study the surfactant cations with a C14 tail form lamella (p close to unity).3-1. The fttll-protonated species form lamella phase on addition of NphS and this separated lamella phase can be dispersed as lamella drops or onions at high temperatures.3-2. The half-protonated species form vesicles on addition of NphS and their charges are reversed as the binding of NphS increases.

(1) 通过改变 pH 值实现可逆的胶束 - 囊泡转变。当油基二甲胺氧化物质子化至 0.5（半质子化状态）时，长纤维状胶束自发形成囊泡，并且通过改变介质的 pH 值可逆地发生这种变化。粘弹性行为从麦克斯韦型特征转变为长纤维胶束的缠结网络，再转变为凝胶状行为。转换速度相当快，大约2小时内就完成了。然而，囊泡悬浮液的粘弹性特性需要更长的时间（约 14 天）才能恢复到大致相同的水平。这种转化很可能不是以类似过渡的方式进行，而是以连续的方式进行。(2)十四烷基二甲基氧化胺(C14DMAO)薄膜在固/溶液界面的结构变化。2-1．云母/溶液界面、半胶束或圆柱体在非离子状态下形成，而双层在半质子化和全质子化状态下形成。2-2．石墨/溶液界面。半胶束的形成与质子化程度无关。(3)萘磺酸盐(NphS)抗衡离子形成C14DMAO的层状和囊泡。这个结果并非微不足道，因为大多数具有 C16 尾部的表面活性剂阳离子形成长纤维状胶束（堆积参数 p 接近 0.5）。在本研究中，具有 C14 尾部的表面活性剂阳离子形成片层（p 接近统一）。3-1。添加 NphS 后，fttll 质子化物质形成片层相，并且这种分离的片层相可以在高温下以片层滴或洋葱形式分散。3-2。添加 NphS 后，半质子化物质形成囊泡，并且随着 NphS 结合的增加，它们的电荷发生逆转。