We investigate the microphase transition of asymmetric diblock copolymer induced by nanorods of different properties using cell dynamics simulation and Brown dynamics.The results show the phase diagram and representat...We investigate the microphase transition of asymmetric diblock copolymer induced by nanorods of different properties using cell dynamics simulation and Brown dynamics.The results show the phase diagram and representative nanostructures of the diblock copolymer nanocomposite.Various structures such as sea-island structure(SI),sea-island and lamellar structure(SI-L),and lamellar structure(L) are observed in the phase diagram.The system undergoes phase transition from SI-L to SI or from L to SI with increasing length of A-like sites for all numbers of nanorods except 10 and 300,and from SI to L with increasing number of nanorods for all lengths of A-like sites.Notably,the polymer system transforms from a tilted layered structure to a parallel lamellar,perpendicular lamellar,and subsequently sea-island structure with increasing length of A-like sites for a rod number of 240.To gain more detailed insight into these structural formation mechanisms,we analyze the evolution kinetics of the system with various lengths of A-like sites of the rods.The pattern evolution and domain growth of the ordered parallel/perpendicular lamellar structure are also investigated.Furthermore,the effects of the wetting strength,rod-rod interaction,polymerization degree,and length of nanorods on the self-assembled structure of asymmetric diblock copolymer/nanorods are studied.Our simulations provide theoretical guidance on the construction of complex-assembled structures and the design of novel functional materials.展开更多
The different confinement shapes can induce the formation of various interesting and novel morphologies, which might inspire potential applications of materials. In this paper, we study the directed self-assembly of d...The different confinement shapes can induce the formation of various interesting and novel morphologies, which might inspire potential applications of materials. In this paper, we study the directed self-assembly of diblock copolymer confined in irregular geometries with a soft surface by using self-consistent field theory. Two types of confinement geometries are considered, namely, one is the concave pore with one groove and the other is the concave pore with two grooves. We obtain more novel and different structures which could not be produced in other two-dimensional（2D） confinements. Comparing these new structures with those obtained in regular square confinement, we find that the range of ordered lamellae is enlarged and the range of disordered structure is narrowed down under the concave pore confinement.We also compare the different structures obtained under the two types of confinement geometries, the results show that the effect of confinement would increase, which might induce the diblock copolymer to form novel structures. We construct the phase diagram as a function of the fraction of B block and the ratio of h/L of the groove. The simulation reveals that the wetting effect of brushes and the shape of confinement geometries play important roles in determining the morphologies of the system. Our results improve the applications in the directed self-assembly of diblock copolymer for fabricating the irregular structures.展开更多
基金Project supported by the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi(Grant No.2019L0957)the Key Research and Development Project of the Introduction of High-Level Scientific and Technological Talents in Lvliang(Grant No.201701102)the Shanxi Provincial Natural Science Foundation,China(Grant No.201801D221109)。
文摘We investigate the microphase transition of asymmetric diblock copolymer induced by nanorods of different properties using cell dynamics simulation and Brown dynamics.The results show the phase diagram and representative nanostructures of the diblock copolymer nanocomposite.Various structures such as sea-island structure(SI),sea-island and lamellar structure(SI-L),and lamellar structure(L) are observed in the phase diagram.The system undergoes phase transition from SI-L to SI or from L to SI with increasing length of A-like sites for all numbers of nanorods except 10 and 300,and from SI to L with increasing number of nanorods for all lengths of A-like sites.Notably,the polymer system transforms from a tilted layered structure to a parallel lamellar,perpendicular lamellar,and subsequently sea-island structure with increasing length of A-like sites for a rod number of 240.To gain more detailed insight into these structural formation mechanisms,we analyze the evolution kinetics of the system with various lengths of A-like sites of the rods.The pattern evolution and domain growth of the ordered parallel/perpendicular lamellar structure are also investigated.Furthermore,the effects of the wetting strength,rod-rod interaction,polymerization degree,and length of nanorods on the self-assembled structure of asymmetric diblock copolymer/nanorods are studied.Our simulations provide theoretical guidance on the construction of complex-assembled structures and the design of novel functional materials.
基金Project supported by the Specialized Research Fund for the Doctoral Program of Higher Education of China(Grant No.20121404110004)the Research Foundation for Excellent Talents of Shanxi Provincial Department of Human Resources and Social Security+2 种基金Chinathe Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi ProvinceChina
文摘The different confinement shapes can induce the formation of various interesting and novel morphologies, which might inspire potential applications of materials. In this paper, we study the directed self-assembly of diblock copolymer confined in irregular geometries with a soft surface by using self-consistent field theory. Two types of confinement geometries are considered, namely, one is the concave pore with one groove and the other is the concave pore with two grooves. We obtain more novel and different structures which could not be produced in other two-dimensional（2D） confinements. Comparing these new structures with those obtained in regular square confinement, we find that the range of ordered lamellae is enlarged and the range of disordered structure is narrowed down under the concave pore confinement.We also compare the different structures obtained under the two types of confinement geometries, the results show that the effect of confinement would increase, which might induce the diblock copolymer to form novel structures. We construct the phase diagram as a function of the fraction of B block and the ratio of h/L of the groove. The simulation reveals that the wetting effect of brushes and the shape of confinement geometries play important roles in determining the morphologies of the system. Our results improve the applications in the directed self-assembly of diblock copolymer for fabricating the irregular structures.
