The Phase Behaviors Of The Polymer System Under Cylindrical Nanopore Confinement

With the self-assembly field of soft materials expanding and in-depth, the investigation of phase behaviours for the polymerconfined system has become a hot research topic. The geometry ofthe confinement and surface-polymer interaction influence theself-assembly process and can generate novel microstructures thatmay have potential novel applications. Therefore, the blockcopolymer self-assembly under confinement has a strong practicaland theoretical value.In this thesis, by using cell dynamical system (CDS) method, weInvestigate the domain morphology of the complex polymers in acylindrical nanopore and cylindrical constrained block-copolymersin the field-induced.Firstly, we study the phase behaviour of copolymer-homopolymermixtures in a cylindrical nanopore. It is observed that theequilibrium morphology of the confined system depends sensitivelyon the pore diameter, pore length, the affinity of pore suface tocopolymer, the interactions between different monomers, and therelative concentrations of diblock copolymer-homopolymer, and themorphological transitions between different structures are also discussed. Our model provides a simple way to controlself-assembly structures of soft material.Secondly, we investigate the orientational order transition ofdiblock copolymer confined system in the presence of periodicoscillatory particles. Under suitable conditions, by changing theoscillatory amplitude and frequency, we observe the orientationalorder transition of a lamellar microphase structure from theisotropic state to a state parallel to the oscillatory direction, andthen from the parallel state to a state perpendicular to theoscillatory direction. This model system may provide a simple wayto realize orientational order transition of soft materials bychanging the oscillatory field. The formation of the new structuregive some guiding significance on the synthesis of new materialsexperimentally.Through these studies, we learn that the polymers confinedsystem will form a variety of self-assembled structures, which willprovide a useful reference in our experimental system to achievethe ordered structure of soft materials.