Sagnelli Domenico, Rippa Massimo, D'Avino Amalia, Vestri Ambra, Marchesano Valentina, Petti Lucia
Institute of Applied Sciences and Intelligent Systems of CNR, 80072 Pozzuoli, Italy.
Micromachines (Basel). 2022 Oct 3;13(10):1665. doi: 10.3390/mi13101665.
Azobenzene is one of the most investigated photo-responsive liquid crystalline molecules. It can isomerize between two different isoforms, trans (E) and cis (Z) configurations, when stimulated by light. It is used as a molecular engine in photo-mobile materials (PMPs). The use of liquid crystals (LCs) as building blocks enhances the mechanical properties of the PMPs. It is not easy to obtain PMPs with monodomain configurations when the LCs are 100% azobenzene. In this work, we studied three LC mixtures, describing the thermo/mechanical phenomena that regulate the actuation of such materials. The nematic temperature of the LC elastomers was measured and the PMPs carefully characterized for their bending and speed capability. Our finding suggests that the ratio between linear and cross-linker monomer greatly influences the nematic temperature of the mixture. Furthermore, 100% azobenzene materials polymerized using dicumyl peroxide can be useful to design polarization-selective switches.
偶氮苯是研究最为深入的光响应液晶分子之一。受到光照刺激时，它能够在反式（E）和顺式（Z）两种不同异构体构型之间发生异构化。它被用作光驱动材料（PMPs）中的分子引擎。将液晶（LCs）用作构建单元可增强PMPs的机械性能。当液晶为100%偶氮苯时，要获得具有单畴构型的PMPs并不容易。在这项工作中，我们研究了三种液晶混合物，描述了调节此类材料驱动的热/机械现象。测量了液晶弹性体的向列相温度，并对PMPs的弯曲和速度能力进行了仔细表征。我们的研究结果表明，线性单体与交联剂单体的比例对混合物的向列相温度有很大影响。此外，使用过氧化二异丙苯聚合的100%偶氮苯材料可用于设计偏振选择性开关。
