Rešetič AndraŽ, Milavec Jerneja, Domenici Valentina, Zupančič BlaŽ, Bubnov Alexej, Zalar Boštjan
J. Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia.
Phys Chem Chem Phys. 2020 Oct 21;22(40):23064-23072. doi: 10.1039/d0cp04143b.
Polymer-dispersed liquid crystal elastomers have been recently introduced as a thermomechanically active composite material, consisting of magnetically oriented liquid crystal elastomer particles incorporated in a cured polymer matrix. Their thermomechanical properties are largely governed by the degree of imprinted particle alignment, which can be assessed by means of deuterium perturbed 2H-NMR. Spectra of samples with various degrees of imprinted particle alignment were recorded and the results simulated using the discrete reorientational exchange model developed for determining the dispersion of liquid crystal elastomer's domain orientational distribution. We show that the model can be applied to measure the orientational distribution of embedded liquid crystal microparticles and successfully determine the orientational order parameter in the composite system. Thermomechanical measurements correlate well with the obtained results, thus additionally confirming the validity of the applied method.
聚合物分散液晶弹性体最近作为一种热机械活性复合材料被引入，它由掺入固化聚合物基体中的磁取向液晶弹性体颗粒组成。它们的热机械性能在很大程度上由印记颗粒排列程度决定，这可以通过氘扰动2H-NMR来评估。记录了具有不同印记颗粒排列程度的样品的光谱，并使用为确定液晶弹性体畴取向分布的离散重取向交换模型对结果进行了模拟。我们表明，该模型可用于测量嵌入液晶微粒的取向分布，并成功确定复合体系中的取向序参数。热机械测量结果与所得结果相关性良好，从而进一步证实了所应用方法的有效性。
