Formation and Dynamics of Self-Organized Structures in Complex Fluids

在本研究中，我们将自洽场理论（SCF）应用于各种实际问题，这是致密聚合物体系中空间非均质结构理论预测的有用工具。我们还将自洽场论推广到动力学问题。我们首先通过将SCF理论应用于致密聚合物体系中的各种问题来验证其有效性。我们研究了三嵌段共聚物溶液中胶束的形成、嵌段共聚物加入后表面张力的变化、聚合物接枝胶体颗粒之间的相互作用等。我们发现聚合物构象的改变对胶体粒子之间的相互作用和界面性质起着重要的作用。接下来，我们尝试将SCF理论扩展到动力学问题。将SCF理论推广到动力学问题的最简单方法是使用线性扩散的假设，即由化学势的梯度诱导段的电流（菲克斯定律）。利用动态自旋流场理论，我们研究了固体表面上聚合物共混薄膜的畴形成，以及嵌段共聚物共混中微观相和宏观相分离竞争引起的复杂畴形成。我们观察到与现实系统相似的相分离动力学和畴结构。通过与劳斯模型的比较，验证了该模型的有效性。在大变形状态下，当链构象受到外力的极大变形时，上述动力学SCF理论就失效了。为了评估链构象的变形程度，我们引入了非各向同性的键分布函数。通过对聚合物刷系剪切变形的研究，验证了这一新的动态SCF理论。

In this research, we applied the self-consistent field (SCF) theory, which is a useful tool in theoretical predictions of the spatially inhomogeneous structures in dense polymer systems, to various practical problems. We also extended the self-consistent field theory to dynamical problems.We first checked the validity of the SCF theory by applying it to various problems in dense polymer systems. We studied micellar formation in tri-block copolymer solutions, Change in the surface tension by addition of block copolymers, interactions between polymer-grafted colloidal particles, and so on. We found that changes in the polymer conformation play important roles in interactions between colloidal particles and interfacial properties.Next, we tried to extend the SCF theory to dynamical problems. The simplest way of extending the SCF theory to dynamical problems is to use an assumption of the linear diffusion, i.e. a current of the segments is induced by the gradient of the chemical potential (Ficks law). Using this dynamical SCF theory, we studied a domain formation in thin polymer blend film on a solid surface, and complex domain formations induced by a competition between micro-and macro-phase separations in block copolymer blend. We observed similar phase separation dynamics and domain structures as in realistic systems. We also checked the validity of this dynamical model by comparing it with Rouse model.In a large deformation regime where the chain conformation is considerably deformed by external forces, the above dynamical SCF theory breaks down. In order to evaluate the degree of deformation of the chain conformation, we introduced non-isotropic bond-distribution functions. This new dynamical SCF theory is verified by studying a polymer brush system under shear deformation.