受限薄膜中不对称两嵌段共聚高分子的微相形态

Microphases of Asymmetric Diblock Copolymers in Confined Thin Films

用强分凝理论方法研究了组分不对称 (f≈ 0 2 5 )的两嵌段共聚高分子在受限薄膜中的微相形态———层状相、平行柱状相和垂直柱状相 .发现对中性基底 ,无论薄膜厚度为多少 ,垂直柱状相总是最稳定的相 ;而对亲少数相的基底 ,嵌段高分子的平均组成以及基底和两嵌段之间的相互作用能对薄膜体系的相行为有决定性影响 .随着薄膜厚度的增加 ,层状相 (包括奇数和偶数层数 )。

Microphase formation of an asymmetric diblock copolymer (with f approximate to 0.25) confined in a thin film was investigated by using strong segregation theory. The stability of microphases, such as surface-parallel lamella, surface-parallel and surface-perpendicular cylinders, was determined. It was found that for neutral substrates the surface-perpendicular cylinders are always stable as the film thickness is varied. However, for substrates that prefer the minor component, the stability of these microphases is crucially influenced by the composition of the diblock and the surface interactions between the diblock and the two substrates. Therefore, varying the thickness of the thin film, surface-parallel lamella, including both odd and even layers, surface-parallel and surface-perpendicular cylinders could alternatively exist.