Elucidation of the Mechanism of Stress-Induced Circular Dichroic Inversion of Cellulosic/Polymer Liquid Crystalline Composites
Elucidation of the Mechanism of Stress-Induced Circular Dichroic Inversion of Cellulosic/Polymer Liquid Crystalline Composites
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DOI：
10.1021/acs.macromol.9b02741
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发表时间：
2020-04-28
期刊：
影响因子：
5.5
通讯作者：
Teramoto, Yoshikuni
中科院分区：
文献类型：
--
作者：
Miyagi, Kazuma;Teramoto, Yoshikuni
我们通过建模方法揭示了通过施加压应力诱导纤维素/聚合物胆甾型液晶（ChLC）复合材料圆二色性反转的机制。我们研究了一个简单系统的圆二色性行为，该系统是与压缩的非 ChLC 复合材料叠加的 ChLC 复合材料，以避免 ChLC 的结构变化。根据压缩样品双折射的模型计算了叠加复合材料的理论圆二色光谱，结果与实验光谱吻合良好。因此，发现应力引起的圆二色性反转是由复合材料的组分聚合物由于压缩而线性取向引起的。通过热处理恢复原始圆二色性也可以用线性取向组分聚合物的弛豫来解释。
We revealed the mechanism of circular dichroic inversion of cellulosic/polymer cholesteric liquid crystalline (ChLC) composites induced by applying compressive stress through a modeling approach. We examined the circular dichroic behavior of a simple system, which is a ChLC composite superimposed with compressed non-ChLC composite, to avoid structural change in ChLC. Theoretical circular dichroism spectra of the superimposed composites were calculated from the model based on the birefringence of the compressed sample and showed good agreement with experimental spectra. Hence, the stress-induced circular dichroic inversion was found to be caused by the linear orientation of component polymers of composites due to compression. Recovery of original circular dichroism by thermal treatment was also explained in terms of the relaxation of the linearly oriented component polymers.