Department of Bio- and Material Photonics, Chitose Institute of Science and Technology, Chitose, Hokkaido, Japan.
Langmuir. 2012 Mar 13;28(10):4811-4. doi: 10.1021/la204789g. Epub 2012 Feb 29.
The homogeneous alignments of helical rod-like polysilanes on a rubbed polyimide alignment layer were investigated by polarized optical microscopy (POM) and atomic force microscopy (AFM) analyses. The POM and AFM observations determined that polysilanes with a series of aliphatic side chains helically arranged around the main chains were tilted to the right and left by 33° from the rubbing direction when the handedness of the side-chain helical array is left and right, respectively. It is interesting to note that the side-chain arrays run perpendicular to the rubbing direction on the polyimide surface, which is different from intuitive "knob and hole" packing of the extended polyimide chain and the helical grooves between the side-chain arrays surrounding the polysilane backbone. More surprisingly, both right- and left-tilting smectic domains were simultaneously observed with an equal probability for an achiral polysilane, which apparently has the interconverting right- and left-handed helical segments separated by helical reversals. This might be the first observation of the chiral segregation of dynamic helical polymers.
通过偏光显微镜（POM）和原子力显微镜（AFM）分析研究了螺旋棒状聚硅烷在摩擦聚酰亚胺取向层上的均匀排列。POM 和 AFM 观察结果表明，当侧链螺旋排列的手性分别为左旋和右旋时，具有一系列脂肪族侧链围绕主链螺旋排列的聚硅烷相对于摩擦方向向右和向左倾斜 33°。有趣的是，注意到侧链排列在聚酰亚胺表面上垂直于摩擦方向，这与延伸聚酰亚胺链的直观“凸块和凹坑”包装以及围绕聚硅烷主链的侧链排列之间的螺旋凹槽不同。更令人惊讶的是，对于手性聚硅烷，同时以相等的概率观察到右倾斜和左倾斜的近晶畴，显然，它具有由螺旋反转分开的互变的右手和左手螺旋段。这可能是动态螺旋聚合物手性分离的首次观察。
