Development of Novel Scattering and Reflection Techniques for the Study of Dynamics in Polymer Assemblies at Interfaces

为了检测和澄清聚合物在界面上的特定动力学，特别是水面上的聚合物单分子层，我们开发了一种新型的仪器--表面动态光散射(SDLS)。首先，我们利用X射线反射仪研究了水上聚合物单分子膜的纳米结构。用来制备单层膜的聚合物是我们实验室合成的聚(硅环丁烷)-b-聚甲基丙烯酸。结果发现，水面下的亲水层不是一个简单的刷层，而是由两层组成，即高密度的地毯状刷层和聚合物刷层。地毯层被认为是为了避免疏水层与水接触而形成的。其厚度几乎为15Å，与聚合物链长和表面压力无关。这是一个相当新奇的发现。在高pH条件下，电刷层变厚。此外，还研究了盐效应对刷层结构的影响。SDLS仪器为De…更多地签署了外差光学系统的原理。通过反复试验，我们发现利用光栅分束是SDLS光学最好的方法。接下来，我们发现仪器工作台的小振动对SDLS数据有很大的影响。为此，我们为仪器引入了一种主动隔振台，并证实了这种布置对我们的目的是良好的。在仪器中安装了一个压电绝缘体，以在水面系统上产生一个小的人工波。典型振幅为1微米，典型频率为100-300赫兹。我们的SDLS清楚地探测到了这一表面波，并得到了振荡的时间关联函数。这种振荡是聚合物单分子膜对水的响应。当增加100赫兹的频率时，我们观察到100,200,300赫兹的响应频率。而当压电体加入200赫兹波时，仅观察到100赫兹的响应。这意味着聚合物单分子层具有特征的粘弹性。从而证实了我们研制的SDLS仪器可以用于获取水面单分子膜的定量信息。较少

To detect and clariy the specific dynamics in polymers at interfaces, especially polymer monolayer on water surface, we have developed a novel instrument, Surface Dynamic Light Scattering (SDLS). First, we investigated the nanostructure of polymer monolayer on water by utilizing X-ray reflectometrer. The polymer used for monolayer preparation was poly (silacyclobutane)- b-poly(methacrylic acid), which was synthesized in our laboratory. As a result, we found that the hydrophilic layer under water surface is not a simple brush layer but it composed of two layers, i.e. carpet-like layer with high polymer density and polymer brush layer. The carpet layer is thought to be formed to avoid contact between hydrophobia layer and water. Its thickness was almost 15Å independent the polymer chain length and surface pressure. This is a quite novel finding. The brush layer became thicker under high pH condition. Also, salt effect for brush layer structure was also investigated.SDLS instrument was de … More signed with the principle of heterodyne optical system. By a try-and-error, we found that a beam splitting by grating is the best method for SDLS optics. Next, we found that the small vibration of the instrument table has a large effect for SDLS data. Hence, we introduced an active vibration-isolation table for instrument, and it was confirmed that this arrangement is fine for our purpose. A piezo-insulator was installed in the instrument to produce a small artificial wave on water surface system. Typical amplitude was 1 micrometer and the typical frequency was in the range of 100-300 Hz. This surface wave was clearly detected by our SDLS and we obtained the time correlation function with oscillation. This oscillation is a response from polymer monolayer on water. When the frequency 100Hz was added, we observed response frequency at 100, 200, 300 Hz. However, when 200Hz wave was added by piezo, only 100Hz response was observed. This means that the polymer monolayer has a characteristic viscoelasticity. Hence it was confirmed that the SDLS instrument we have developed can be used to obtain quantitative information for monolayer on water surface. Less