标题: 使用模板法制备之多孔性与豌豆形高分子奈米材料
Fabrication of Porous and Peapod-like Polymer Nanomaterials by Using the Template Method
作者: 魏慈慧
Wei, Tzu-Hui
陈俊太
Chen, Jiun-Tai
应用化学系硕博士班
关键字: 阳极氧化铝;相分离;多孔性高分子奈米结构;高分子奈米豌豆;雷利不稳定性;Anodic aluminum oxide;Phase separation;Porous polymer nanostructures;Polymer nanopeapods;Rayleigh instability
公开日期: 2012
摘要:   由于一维高分子奈米结构可以应用在太阳能电池或是生物感测器等方面的研究,所以近年来引起了相当大的注意。其中一种被广泛用来制作一维高分子奈米结构的方法为模板法,在此方法中,模板被当作支架使用。虽然模板法已经被用来制作许多不同种类的高分子奈米结构,但是对这些利用模板而成形的高分子奈米结构来说,其性质和形貌的控制仍然是个很大的挑战。
  此篇论文主要的研究分为两个部分,第一部分在第二章“利用阳极氧化铝表面诱导之相分离制作多孔性高分子奈米结构”中。在这部分的研究里,我们主要探讨阳极氧化铝(Anodic Aluminum Oxide, AAO)模板内多孔性高分子奈米结构的形成,此形成主要是经由高分子溶液的表面诱导式相分离而造成。聚甲基丙烯酸甲酯(poly(methyl methacrylate), PMMA)和四氢呋喃(tetrahydrofuran, THF)在此被用来研究表面诱导式相分离的转变过程。随着AAO模板浸泡在高分子溶液中的时间变长,富含溶剂微滴的大小会因为粗化的过程而变大,造成多孔性高分子奈米结构的形成。我们还改变了浸泡时间、高分子的浓度、高分子的分子量、以及溶剂的质量等实验参数来进一步判断粗化过程的机制。
  此篇论文主要研究的第二个部分在第三章“在阳极氧化铝模板内利用双溶液润湿法制作高分子奈米豌豆”中。在此部份的研究里,我们探讨了在AAO模板的奈米孔洞内利用双溶剂策略而制得的豌豆形高分子奈米结构。首先,我们先将聚苯乙烯(polystyrene, PS)与二甲基甲醯胺(dimethylformamide, DMF)的溶液导入AAO模板的奈米孔洞内,接着再将此样品浸泡在PMMA与乙酸(acetic acid)的溶液中。因为乙酸和AAO模板的管壁表面有较强的作用力,所以PMMA溶液将会占据在PS溶液和AAO模板的管壁之间,而PS溶液则会聚集在奈米孔洞的中间区域。在溶剂挥发之后,就可得到类似豌豆形状的PS/PMMA复合奈米结构。为了进一步确认豌豆形高分子奈米结构的生成,我们还利用了环己烷(cyclohexane)来选择性移除PS以及乙酸来移除PMMA。此奈米结构的形成过程和雷利不稳定性(Rayleigh instability)有很大的关联,我们也藉由改变高分子浓度或分子量等实验参数来研究此结构的形成。此工作不仅提供了一个简单的方法来制作高分子复合奈米材料并且控制其形貌和尺寸,对于在受限的几何形状中高分子和溶剂的作用,也提供了更深入的了解。
  One-dimensional polymer nanostructures have attracted great attention because of their applications in different areas such as solar cells or biosensors. To fabricate one-dimensional polymer nanostructures, one of the extensively used methods is the template method, in which the template is used as a scaffold. Although various polymer nanostructures have been prepared by using the template method, it is still a great challenge to control the properties and morphologies of template-based nanostructures.
  This thesis is divided into two main parts. The first part is included in chapter 2. We study the formation of porous polymer nanostructures fabricated by surface-induced phase separation of polymer solutions in anodic aluminum oxide (AAO) templates. Poly(methyl methacrylate) (PMMA) and tetrahydrofuran (THF) are used to study the evolution process of the surface-induced phase separation. With longer immersion times of the AAO templates in the polymer solutions, the sizes of the solvent-rich droplets are increased by the coarsening process, resulting in the formation of porous polymer nanostructures. The coarsening mechanism is further confirmed by adjusting the experimental parameters including the immersion time, the polymer concentration, the polymer molecular weight, and the quality of solvent.
  The second part of this thesis is included in chapter 3. We investigate the formation of core-shell polymer nanostructures by using a double solution strategy in the nanopores of anodic aluminum oxide (AAO) templates. A polystyrene solution in dimethylformamide (DMF) is first introduced into the nanopores of the AAO templates. Then the sample is later introduced into a PMMA solution of acetic acid. Because acetic acid has a stronger interaction to the wall surface of the AAO template, the PMMA solution can occupy the place between the PS solution and the walls of AAO templates. The polymer solution is isolated in the center of the nanopores. After the evaporation of the solvent, peapod-like PS/PMMA composite nanostructures are obtained.
  The peapod-like polymer nanostructures are confirmed by selective removal of the PS using cyclohexane or the PMMA using acetic acid. The formation process of the polymer nanostructures is related to the Rayleigh-instability-type transformation and is further investigated by varying the experimental parameters such as the polymer concentration or the polymer molecular weight. This work not only offers a simple approach to prepare polymer nanocomposites with controllable morphologies and sizes, but also provides a deeper understanding of polymer-solvent interactions in confined geometries.
URI: http://140.113.39.130/cdrfb3/record/nctu/#GT070052534
http://hdl.handle.net/11536/72207
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