The influence of flexible segments on liquid crystalline properties in terms of solubility parameters. An attempt at quantitative interpretation
The influence of flexible segments on liquid crystalline properties in terms of solubility parameters. An attempt at quantitative interpretation
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DOI：
10.1021/jp0536448
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发表时间：
2006-02-16
影响因子：
3.3
通讯作者：
Bialecka-Florjanczyk, E
中科院分区：
文献类型：
--
作者：
Bialecka-Florjanczyk, E
本文综述了棒状嵌段分子的相行为与组成链段极性的关系。结果发现，中间相形成的能力与柔性链和刚性核之间的极性特征的差异有关。因此，与极性刚性核连接的极性聚（环氧乙烷）基团降低了中间相稳定性，但当与一些非极性结构单元放在一起时是有利的。本文还尝试用汉森溶度参数δ和Flory相互作用参数chi定量估计分子不同部分的不相容性。在chi参数的基础上，计算了这些链段的混合吉布斯自由能。吉布斯自由能的变化反映了链段的相容性和它们的相分离倾向，以及介晶刚性核的体积分数反映了它们在一个方向上排列的能力，这在中间相形成的类型方面似乎是至关重要的。
The phase behavior of some rodlike block molecules has been reviewed with reference to the polarity of constituent segments. It was found that the ability of the mesophase formation is connected with differences in polar character between the flexible chains and rigid cores. Thus the polar poly(oxyethylene) group connected with the polar rigid core reduces mesophase stability but is advantageous when put together with some apolar building blocks. An attempt at quantitative estimation of the incompatibilities of different parts of molecules by means of Hansen solubility parameters delta and Flory interaction parameters chi has also been made. On the basis of chi parameters the Gibbs free energies of mixing of these segments were calculated. The changes of Gibbs free energy reflecting the compatibility of segments and their tendency to the phase separation and the volume fraction of mesogenic rigid core reflecting their ability to arrangement in one direction appear to be crucial in terms of type of the mesophase formation.