权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

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

在平移和旋转不变性条件下，聚合物混合物的相分离已被广泛研究。因此，相分离随时间和空间均匀且各向同性地进行。在这项研究中，相分离的混合物组成的二苯乙烯标记的聚苯乙烯（PSS）和聚（乙烯基甲基醚）（PVME）的诱导下，通过使用光强度分布的破胶条件。在浓度波动的平移不变性被打破的实验中，使用具有明确定义的强度梯度的紫外光来诱导相分离。各向异性的形态出现的优选取向几乎垂直于偏振方向（E）。另一方面，利用二苯乙烯的偏振选择性光致异构化作用，利用线偏振光来破坏相分离的旋转不变性，在第一类实验中，通过改变线偏振光的偏振选择性， ...更多信息光强度的梯度倾向于仅沿着垂直于梯度的方向发展。在强度梯度的上游中的相分离以几乎类似于使用均匀强度的情况的动力学进行。另一方面，相分离在较低的流的演变更快的照射时间。沿梯度沿着观察到的相分离动力学是由梯度的大小决定的，并且似乎是普遍的并且与光强度无关。现在，相位分离取决于相对于偏振光方向E的相对取向。结果发现，在这种特殊的情况下，相分离进行最快的沿着方向的E，而它变得非常缓慢沿着垂直方向，结合先前获得的数据与实验使用的温度梯度（Physica D 84，23，1995），在这项研究中获得的结果表明，一种新的和有效的方法来设计聚合物的可控梯度结构。少