Magnetic liquid crystalline hybrid materials: Synthesis of anisotropic, magnetic hybrid materials by organised integration of nanoparticles in liquid crystalline matrices

通过在复杂的液晶基质中稳定磁性纳米颗粒，我们的目标是制备具有有趣磁光性能的杂化材料。纳米磁性粒子的集成导致了粒子与液晶分子之间的复杂相互作用，从而产生了具有新结构和性能的各向异性、柔软的杂化材料。在之前的资助期间，我们合成了各种球形和棒状的铁氧体纳米粒子。通过将磁性纳米颗粒与DIVERS(PRO)介晶配体功能化，磁性纳米颗粒的表面性质被专门设计成稳定的液晶杂化产物，例如在4-氰基-4‘-戊基联苯(5CB)中。为此，我们合成了DIVERS(PRO)介晶配体，它包含一个介晶单元(即氰基联苯、辛基联苯)和一个磁性纳米颗粒的结合基团，两者都通过不同长度的烷基相连。这种杂化材料表现出了有趣的磁光性质。基于我们之前的研究结果，我们计划合成并使用树枝状(PRO)介晶配体来稳定较大的各向异性磁性纳米颗粒在液晶基质中，从而进一步改善其磁光性能。特别是，我们想要开发形状各向异性磁性纳米颗粒的潜力来控制中间相的有序参数。与优先计划中的其他小组合作，我们计划对磁光和流变学性质进行基础研究。这一结果将为进一步的理论研究奠定基础。

By stabilizing magnetic nanoparticles in complex, liquid crystalline matrices, we aim at the preparation of hybrid materials with interesting magneto-optical properties. The integration of nanoparticulate magnetic particles leads to complex interactions between the particles and the liquid crystal molecules and to anisotropic, soft hybrid materials with novel structures and properties. Within the previous funding periods, we synthesized a variety of spherical and rod-shape ferrite nanoparticles. Via the functionalization of the magnetic nanoparticles with divers (pro)mesogenic ligands, the surface properties of the magnetic nanoparticles were specifically engineered to yield stable, liquid crystalline hybrids, e.g. in 4-cyano-4‘-pentylbiphenyl (5CB). For this purpose, we synthesized divers (pro)mesogenic ligands, which contained a mesogenic unit (i.e. cyanobiphenyle, octylbiphenyle) and a binding group for the magnetic nanoparticles both linked by an alkyl group of varying length. The hybrid materials revealed interesting magneto-optical properties. Based on our previous results, we plan to synthesize and use dendritic, (pro)mesogenic ligands for the stabilization of larger and anisotropic magnetic nanoparticles in the liquid crystalline matrix, further improving the magneto-optical properties. In particular, we would like to exploit the potential of shape anisotropic magnetic nanoparticles to control the order parameters of the mesophase. In cooperation with other groups in the priority program we plan to do fundamental investigations on the magneto-optical and rheological properties. The results will serve as a basis for further theoretical investigations.