Ma Xu, Han Yucen, Zhang Yan-Song, Geng Yong, Majumdar Apala, Lagerwall Jan P F
Experimental Soft Matter Physics group, Department of Physics & Materials Science, University of Luxembourg, 1511, Luxembourg, Luxembourg.
Department of Mathematics and Statistics, University of Strathclyde, Glasgow, United Kingdom.
Nat Commun. 2024 Feb 15;15(1):1404. doi: 10.1038/s41467-024-45674-5.
Multiple emulsions are usually stabilized by amphiphilic molecules that combine the chemical characteristics of the different phases in contact. When one phase is a liquid crystal (LC), the choice of stabilizer also determines its configuration, but conventional wisdom assumes that the orientational order of the LC has no impact on the stabilizer. Here we show that, for the case of amphiphilic polymer stabilizers, this impact can be considerable. The mode of interaction between stabilizer and LC changes if the latter is heated close to its isotropic state, initiating a feedback loop that reverberates on the LC in form of a complete structural rearrangement. We utilize this phenomenon to dynamically tune the configuration of cholesteric LC shells from one with radial helix and spherically symmetric Bragg diffraction to a focal conic domain configuration with highly complex optics. Moreover, we template photonic microparticles from the LC shells by photopolymerizing them into solids, retaining any selected LC-derived structure. Our study places LC emulsions in a new light, calling for a reevaluation of the behavior of stabilizer molecules in contact with long-range ordered phases, while also enabling highly interesting photonic elements with application opportunities across vast fields.
多重乳液通常由两亲性分子稳定，这些分子结合了相互接触的不同相的化学特性。当其中一相为液晶（LC）时，稳定剂的选择也决定了其构型，但传统观点认为LC的取向有序对稳定剂没有影响。在此我们表明，对于两亲性聚合物稳定剂的情况，这种影响可能相当大。如果将液晶加热到接近其各向同性状态，稳定剂与液晶之间的相互作用模式就会改变，从而引发一个反馈回路，以完全结构重排的形式在液晶上产生回响。我们利用这一现象动态地将胆甾型液晶壳的构型从具有径向螺旋和球对称布拉格衍射的构型调整为具有高度复杂光学特性的焦锥域构型。此外，我们通过将液晶壳光聚合为固体来制备光子微粒模板，保留任何选定的源自液晶的结构。我们的研究使液晶乳液有了新的认识，需要重新评估稳定剂分子与长程有序相接触时的行为，同时还能实现极具趣味性的光子元件，并在广泛领域具有应用机会。
