Copolymer-homopolymer mixtures in a nanopore

• Published in: Chinese physics B 2013-09, Vol.22 (9), p.525-533
• Main Author: 张玲翠 孙敏娜 潘俊星 王宝凤 张进军 武海顺
• Format: Article
• Language: English
• Subjects: Copolymers; Cylinders; Dynamic tests; Dynamics; Ginzburg-Landau理论; Monomers; Morphology; Nanostructure; Porosity; Simulation; 二嵌段共聚物; 动力学仿真; 均聚物; 混合物; 纳米孔; 结构效应; 表面效应
• ISSN: 1674-1056; 2058-3834; 1741-4199
• DOI: 10.1088/1674-1056/22/9/096401

We have performed the cell dynamics simulation with the time-dependent Ginzburg-Landau theory to study the self- assembled morphology of A-B diblock copolymers and C homopolymers in a neutral nanopore. The nanopore diameter and length are systematically varied to examine their effects on the structures of various morphologies and their phase transition. From the simulation, it is observed that the equilibrium morphology of the confined system is sensitive to pore diameter D and pore length Lpore, the phase behavior in neutral nanopores is due to an interplay of two factors： the surface effect and the extension effect. When the nanopore length and the lamellae spacing are not commensurate, the surface effect prevails at small nanopores （small diameters or short lengths）, the extension effect takes over at larger nanopores （large diameters or long lengths）. When the nanopore length and the lamellae spacing are commensurate, the surface effect dominates. Furthermore, the interactions between different monomers are also discussed and we obtain a transition from a tilted pancakes/cylinder structure （Ltilted） to a concentric cylindrical structure with defects and to a concentric cylindrical structure （L｜｜）. We also investigate the effect of the relative concentrations of diblock copolymer-homopolymer and obtain a transition in which the position of the C blocks changes from the outer of the cylinder to the middle of the cylinder and then to the inner of the cylinder with the concentration of the C blocks decreasing.