On the nature of the perforated layer phase in undiluted diblock copolymers

被引:59
作者
Qi, SY
Wang, ZG
机构
[1] CALTECH,DIV CHEM & CHEM ENGN,PASADENA,CA 91125
[2] CALTECH,DIV PHYS MATH & ASTRON,PASADENA,CA 91125
关键词
D O I
10.1021/ma970206t
中图分类号
O63 [高分子化学(高聚物)];
学科分类号
070305 ; 080501 ; 081704 ;
摘要
The nature, stability, and mechanism of formation of the block copolymer perforated lamellar structure are elucidated. This structure is shown to develop from the anisotropic fluctuations of the lamellar phase when it reaches its spinodal. It is proposed that there can be two different perforated lamellar structures, one based on a hexagonal close packed (hcp) lattice and one based on a body-centered cubic (bcc) lattice, with nearly degenerate free energy. In the framework of a Leibler-type free energy functional, it is shown that the perforated lamellar structure is only pseudostable (corresponding to a saddle point in the free energy surface) in the weak-segregation limit but can become metastable in the intermediate-segregation regime, Calculation of the fluctuation spectrum of metastable perforated lamellar structures enables us to explain in a simple and consistent manner several puzzling structural data from small-angle neutron scattering studies.
引用
收藏
页码:4491 / 4497
页数:7
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