Self-organizing Mechanism For Confined Polymer And Polymer/colloid System

Self-assembly/self-organization is one of main properties of soft matter or complex fluids,and now has become a major challenge in understanding the structure and phase transition of soft condensed matter. Therefore,how to understand the structure and phase behavior of many complicated systems in soft matter is an interesting subject .in this thesis,we mainly study the self-assembly behavior of soft materials including diblock copolymer,colloid/polymer films.In chapter 1,we briefly introduced what soft matter is and why we need to study them ?The ordered nanosized structures which are obtained from self-assembly of polymers and polymer-colliod systems can be used as novel functional materials,which play more and more important roles in materials science.Furthermore,there exist many types of soft matters in life organisms,such as biomembranes,DNA,and proteins.The study of such materials is significant not only to scientific research but also to understanding of our life .Now more and more researchers from biology,physics and chemistry have involved in the study of organization in biomaterials.In chapter 2,we firstly describe some useful methods in the study of polymer systems.Then we introduce the self-consistant field theory(SCFT) in detail ,which has been proven to be powerful in calculating equilibrium morphologies in polymers.In SCFT ,the Gauss model includes the conformational entropy of a polymer ,which is represented by a space curve ,it can be used to be predict equilibrium structures ,and analysis the stability of them .Moreover,we also introduce a coarse-graining method for studying the dynamic systems,which is the time depended Ginzburg-Landau equation (TDGL),and use it to study the growth dynamics of polymer domains in phase separating systems.In chapter 3, diblock melts has received great attention in recent years. lamellar,hexagonal are the main structures about them. In a physically confined environment, AB copolymers usually assemble into lamellar structures. Through varying the topology of the substrate, we successfully realize lamellar-hexagonal transitions, lamellar-hexagonal/lamellar transitions and the reentrant of lamellar and hexagonal structures, according to the self-consistent field theory (SCFT). The results provide a new way to control the structures of copolymersIn chapter 4, Using Ginzburg-Landau equation for study of the dynamics process of phase separation of binary mixtures and particle system,the results found that the coupling strength and phase separation kinetics between polymer and particles are key factors in domain structure. It also qualitativly gives a relation between the coupling strength and domain size . This provides an effective way to control polymer particle system with coherent structures.