表面场诱导线性三嵌段共聚物薄膜的微结构及其转变规律

Microstructures and Transformation of Linear Triblock Copolymer Films Induced by Surface Field

采用实空间自洽场理论研究了ABC对称线性三嵌段共聚物薄膜的自组装结构及其转变规律.选取具有特定聚合物参数的对称线性三嵌段共聚物,对无修饰条纹和有修饰条纹的两类薄膜受限表面情况,通过调节其薄膜表面场强度和薄膜厚度,获得了一系列新颖的聚合物薄膜微结构.研究结果表明,在无修饰条纹的单一薄膜受限情况下,共聚物趋向于形成规整有序的层状或穿孔层状结构;而在有条纹修饰情况下,共聚物在相应的条纹修饰区域下发生微相分离并趋于形成水平柱状结构.

The real space self-consistent field theory was applied to investigate microstructures and transformation of linear triblock copolymer films induced by surface field. We choose symmetric composition of eopolymers fA： fB：fC=0.2： 0.6：0.2 and the incompatibility degrees of copotymers are set aSXAB =XAC =XBc = 30. The thickness of films is set to be 4.5Rg or 9Rs in our simulation. In order to obtain a series of novel microstructures under the above two different thicknesses of films,we study two kinds of thin films with non- modified stripes and modified stripes. And in the process of simulation, we can adjust the surface field strength of the thin films regularly. The strongest surface field strength is set equal to the interaction between copolymers （XiwN = 30 ,i∈A,B ,C）. The surface interaction is increased from the weakest surface interaction （XiwN = 5 ） in turn to the strongest surface field strength, and the gap of adjacent two kinds surface field strength is set as z~（iwN=5. Depending on changing these parameters of simulation, we have obtained a wealth of microstructures. The microstructures show that the copolymers tend to form a regular and ordered lamellar or perforated layer confined thin films with non-modified stripes, while in the case of films with modified stripes, the copolymers tends to self assemble into horizontal struetures in their respective modified stripe areas.