Abstract.

Temperature variation of the splay elastic modulus (K₁₁) and rotational viscosity (\( \gamma_{1}\)) have been measured throughout the entire nematic (N phase of a binary liquid crystal system comprising of host calamitic compound, 4^′-octyloxy-4-cyanobiphenyl (8OCB) and small amount of a hockey stick-shaped mesogen, 4-(3-decyloxyphenyliminomethyl) phenyl 4-decyloxycinnamate (SF7). Two different structural conformations play a significant role in the phase behavior leading to a noticeable shrinkage in the nematic width. During cooling in the nematic phase, both K₁₁ and \( \gamma_{1}\) enhance monotonically and divulge an evidence of pretransitional fluctuation near the Smectic-A (Sm-A) transition. With increase in the dopant concentration, the slope of the temperature-dependent K₁₁ and \( \gamma_{1}\) becomes uniformly steeper. The observed variations are explained in accordance with the formation of smectic-like clusters in the nematic phase. A representative model of the smectic-like clusters in the nematic phase is presented. However, the obtained values of \( \gamma_{1}\) have found to be between that of conventional calamitics and typical bent-core mesogens. Measurement of the temperature-dependent orientational order parameter (〈P₂〉 ) and activation energy (E_a) has also been carried out for all the studied mixtures, exhibiting a small augmentation due to the addition of a hockey stick-shaped compound. This indicates an enhancement in intermolecular packing within the mixtures which further influences the molecular motions.

Graphical abstract

中文翻译：

---

在曲棍球棒状和cal状介晶的二元体系中测量粘弹性质。

摘要。

展曲弹性模量（K温度变化₁₁）和旋转粘度（\（\ gamma_ {1} \） ）已经被在整个向列（测量Ñ包括主机棒状化合物，4的二元液晶体系的相^' -辛氧基-4-氰基联苯（8OCB）和少量曲棍球状的液晶元4-（3-癸氧基苯基亚氨基甲基）苯基4-癸氧基肉桂酸酯（SF7）。两种不同的结构构象在相行为中起着重要作用，导致明显的相行为在向列相冷却期间，K ₁₁和\（\ gamma_ {1} \）都单调增强，并在近晶相附近泄漏了过渡前波动的证据。甲（SM-甲）过渡。随着掺杂剂浓度的增加，与温度有关的K ₁₁和\（\ gamma_ {1} \）的斜率均匀变陡。根据向列相中近晶状簇的形成来解释观察到的变化。提出了向列相中近晶状簇的代表性模型。但是，已发现\（\ gamma_ {1} \）的值介于常规的折光法和典型的弯芯液晶元之间。测量与温度有关的取向顺序参数（〈P ₂〉）和活化能（E _a）还对所有研究的混合物进行了测试，由于添加了曲棍球棒状化合物，因此表现出很小的增强。这表明混合物中分子间堆积的增强，这进一步影响了分子运动。

图形概要