铁电向列相液晶的光响应能力

Optical response of ferroelectric nematic liquid crystals

以有机分子RM734为代表的液晶体系是一种具有铁电特性的向列相液晶。为了探究其光刺激响应能力,本文对该液晶分子进行了紫外-可见吸收光谱测量以及UV光照实验。结果表明,当处于低温铁电向列相时,液晶分子在357 nm处有吸收峰,峰值吸光度高达1.74。光照实验现象说明其在365 nm波段的UV光诱导下进行光降解反应的同时能够发生等温相变,从低温铁电向列相相变为高温传统向列相,这种相变行为是可重复的。进一步实验结果显示,改变入射线偏振光的偏振方向或者光强大小能够调控相变速度。具有光响应能力的铁电向列相液晶一定程度上具有可控性,这扩宽了铁电液晶的应用范围,为其光学器件的应用提供了新思路。

The liquid crystal system represented by the organic molecule RM734 is a nematic liquid crystal with ferroelectric properties.In order to explore its response to light stimulation,the UV-visible absorption spectrum measurement and UV illumination experiment were carried out on the liquid crystal molecule.The results show that when the liquid crystal molecule is in the low temperature ferroelectric nematic phase,there is an absorption peak at 357 nm,and the peak absorbance is up to 1.74.The experimental phenomenon of illumination shows that it can undergo isothermal phase transformation when conducting photodegradation reaction under the UV light induction of 365 nm wave band,from low temperature ferroelectric nematic phase to high temperature traditional nematic phase,and this phase transformation behavior is repeatable.Further experimental results show that changing the polarization direction or intensity of the incoming polarized light can control the phase transition speed.In general,ferroelectric nematic liquid crystals with optical response ability are controllable to a certain extent,which broadens the application range of ferroelectric liquid crystals and provides new ideas for the application of their optical devices.