Self-assembled morphologies of diblock copolymers confined in nanochannels: effects of confinement geometry.
Self-assembled morphologies of diblock copolymers confined in nanochannels: effects of confinement geometry.
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DOI：
10.1063/1.2735626
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发表时间：
2007-05
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影响因子：
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通讯作者：
Bin Yu;Pingchuan Sun;Tiehong Chen;Q. Jin;D. Ding;Baohui Li;A. Shi
中科院分区：
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作者：
Bin Yu;Pingchuan Sun;Tiehong Chen;Q. Jin;D. Ding;Baohui Li;A. Shi
采用模拟退火技术和“单位点键涨落”模型研究了嵌段共聚物在不同截面形状通道中的自组装行为。在本体中，在本研究中使用的不对称二嵌段共聚物形成六方填充的圆柱体与周期L0。限制通道的横截面具有不同的形状，包括正三角形、矩形、正方形、正六边形、正八边形和椭圆形。对于给定的几何形状，通道尺寸（由一个或两个长度表征）从非常小到L0的几倍不等。结果发现，限制通道的几何形状和尺寸有很大的影响的结构和对称性的自组装形态。对于三角形、矩形和正方形等低对称性截面，多个填充圆柱与约束通道的对称性是主要的形态。当限制通道成形为诸如正六边形、正八边形或椭圆形时，自发地形成更复杂的结构，诸如螺旋或堆叠的环形。自组装结构的畴间距可以通过限制通道的形状和尺寸来改变。我们的结果与现有的实验是一致的。这些结果表明，嵌段共聚物的自组装结构可以通过限制通道的形状来控制。
The self-assembly of diblock copolymers confined in channels of various shaped cross sections is studied using a simulated annealing technique with the "single-site bond fluctuation" model. In the bulk, the asymmetric diblock copolymers used in this study form hexagonally packed cylinders with period L0. The cross sections of the confining channels are of different shapes including regular triangles, rectangles, squares, regular hexagons, regular octagons, and ellipses. For a given geometry, the channel size (characterized by one or two lengths) is varied from very small to several times of L0. It is found that the geometry and size of the confining channels have a large effect on the structure and symmetry of the self-assembled morphologies. Multiple packed cylinders with the symmetry of the confining channels are the major morphologies for low-symmetry cross sections such as triangle, rectangle, and square. More complex structures such as helices or stacked toroids spontaneously form when the confining channels are shaped such as a regular hexagon, a regular octagon, or an ellipse. The domain spacing of the self-assembled structures can be altered by the shape and size of the confining channels. Our results are consistent with available experiments. These results indicate that the self-assembled structures of block copolymers can be manipulated by the shape of the confining channels.