Study On Self-assembly Behaviof Of Polymer/Nanorod Composite System

Polymer/nanorod composite system is controlled by doping,substrate induced,space limited,chemical reaction induced and applied shear field,flow field,electric field,temperature field,magnetic field and so on.Able to self-assemble to form a variety of novel structures and have better mechanical and optical properties.The self-assembly behavior of polymer/nanorod composite system was studied by cell dynamics and Brownian kinetic method based on Ginzburg-Landau theory.Firstly,we briefly describe the thermodynamics and kinetics of soft matter,polymer nanocomposites,polymer composite system and phase separation in the first chapter.Second,we investigate bulk self-assembly of nanorod /diblock copolymer/ homopolymer composite system in the second chapter.We have systematically studied the effects of number,length,composition ratio,rod-rod interaction,infiltration properties and length of nanorods at the same volume fraction of NRs on the self-assembly of the composites and the phase transitions occurring in the material.An analysis of the phase diagram has been carried out to obtain the formation conditions of the sea island structure nanorod-based aggregate(SI-G),sea island structure nanorod-based dispersion(SI-D),lamellar structure nanorod-based multilayer arrangement(L-MP)and nanowire structure(L-SP).Further analysis of the evolution of domain sizes and the distribution of nanorods angle microphase structure was performed.Our simulation provides a theoretical guidance for the preparation of ordered nanowire structures and a reference for how to improve the function of a polymer nanocomposite material.Third,we study Self-assembled phase behavior of nanorod / block copolymer /homopolymer composite system driven by electric field.We discuss the effects of infiltration properties,length,nanorods infiltration intensity and electric field strength on the behavior of self-assembled phase of polymer mixed system.The results show that the when C-affinity nanorods for longer lengths(L=13).As the change of infiltration intensity and electric field strength,the phase transition of lamellar structure/nanorod bending structure nanowire structure and disordered structure was observed in the polymer mixed system.When the length of the rod is moderate(L=9),it changes with thewetting strength and electric field intensity.The polymer mixed system resulted in the phase transition of the elongated sea(block copolymer AB phase)/island(homopolymer C phase)structure,nanowire structure and disorder structure.When the length of rod is short(L=5),with the change of wetting strength and electric field strength,the self-assembled structure of the polymer mixed system is consistent with the sea-island structure formed by the self-assembly of the system.When nanorods infiltrate component A or B,the effect of electric field on the self-assembled phase structure of polymer mixed system is not obvious.Our simulation results provide theoretical guidance for the experimental preparation of nanowire ordered structures,and provide a new idea for improving the functional properties of polymer nanocomposites in the future.Finally,in the fourth chapter,we summarize the main conclusions of this paper,and hope to provide some reference for the future research work.