Mechanism of Phase Separation of Polymar Blends Induced by a Gradient of Light Intersity

光强度梯度诱导聚合物共混物相分离的机理

基本信息

批准号：
11650932
负责人：
SAKAI Wataru
金额：
$ 2.24万
依托单位：
Kyoto Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

项目摘要

Phase separation of polymer mixtures has been extensively studied under conditions of translational and rotational invariance. As a consequence, phase separation proceeds homogeneously and isotropically with time and space. In this study, phase separation of a mixture composed of stilbene-labeled polystyrene (PSS) and poly (vinyl methyl ether)(PVME) was induced under symmetry-breaking conditions by using a distribution of light intensity. In the experiments where the translational invariance of concentration fluctuations was broken, uv light with a well-defined intensity gradient was used to induce the phase separation. Anisotropic morphology emerge with the preferred orientation almost perpendicular to the polarization direction (E). On the other hand, linearly polarized light was used to brake the rotational invariance of phase separation by taking advantages of the polarization-selective photoisomerization of stilbene.In the first kind of experiments, the morphology induced by a gra … More dient of light intensity tends to develop exclusively along the direction perpendicular to the gradient. The phase separation in the upper stream of the intensity gradient proceeds with the kinetics almost similar to the case of using homogeneous intensity. On the ther hand, phase separation in the lower stream evolves much faster with irradiation time. The phase separation kinetics observed along the gradient is determined by the magnitude of the gradient and seems to be universal and independent from the light intensity.In the second kind of experiments, linearly polarized light was used to produce an orientation distribution of the light intensity. The phase separation depends, now, on the relative orientation with respect to the direction E of the polarized light. It was found, in this particular case, that the phase separation proceeds fastest along the direction of E, whereas it becomes very slow along the perpendicular direction.Combined with the data obtained previously with experiments using a temperature gradient (Physica D 84, 23, 1995), the results obtained in this study suggest a new and efficient way to design polymers with controllable graded structures. Less

在翻译和旋转不变性的条件下，已经对聚合物混合物的相分离进行了广泛的研究。结果，相位分离随时间和空间均匀地进行。在这项研究中，通过使用光强度的分布，在对称性条件下诱导了由Silbene标记的聚苯乙烯（PSS）和聚（乙烯基甲基醚）（PVME）组成的混合物的相分离。在破坏浓度波动的平移不变性的实验中，使用定义明确的强度梯度的紫外线来诱导相位分离。优选方向几乎垂直于极化方向（E），各向异性形态的出现。另一方面，通过利用Silbene的极化选择性的光异构化，使用线性极化的光来制动相位分离的旋转不变性。在第一种实验中，GRA引起的形态……更大的光强度倾向于倾向于沿梯度直至始终发展。强度梯度上流流中的相位分离以几乎与使用均匀强度的情况相似的动力学进行。在手上，下层流中的相位分离随着辐照时间的变化速度更快。沿梯度观察到的相分离动力学由梯度的幅度确定，并且似乎是通用的，并且与光强度独立。在第二种实验中，使用线性极化光线来产生光强度的方向分布。相对于极化光的方向E，相位分离取决于相对方向。在这种特殊情况下，发现相位分离沿E方向进行最快，而沿垂直方向变得非常缓慢。c.com.com以先前使用温度梯度进行实验获得的数据（Physica d 84，23，1995），这项研究在这项研究中获得的结果提出了一种具有控制级别结构的设计的新方法。较少的