Soft materials of europium β-diketonate complexes constructed in lyotropic liquid crystals (LLCs) mediated by ionic liquids (ILs) are impressive for their excellent luminescence performance and stability. For the aim to further improve their mechanical processability and luminescent tunablility, the polyoxyethylene phytosterols (BPS-n) were introduced here as structure directing agents to prepare relatively “rigid” lamellar luminescent LLCs in 1-butyl-3-methyl-imidazolium hexafluorophosphate by doping europium β-diketonate complexes with different imidazolium counterions. As a result of the solvophobic sterol ring structure of BPS-n, the more effective isolation and confinement effects of europium complexes could be achieved. The longest fluorescence lifetime and the highest quantum efficiency reported so far for europium containing lyotropic organized soft materials were thus obtained. Changing the molecular structures of BPS-n with different oxyethylene chains or doped complexes with imidazolium counterions of different alkyl chain lengths, the spacings of lamellar LLC matrixes and position of dispersed complexes became tunable. The measured luminescent and rheological properties for such composite LLCs showed a dependence on the rigidity and isolation capability afforded by sterol molecules. It was also found that the increase of counterion alkyl chain length would weaken the LLC matrix’s confinement and isolation effects and therefore exhibit the deteriorated luminescence performance. The enhanced luminescence efficiency and stability of doped BPS-n LLCs reflected the excellent segregation of europium complexes from each other and therefore the reduced self-quenching process. The obtained results here present the designability of LLC matrixes and their great potential to promote achieving the luminescence tunability of soft materials.

中文翻译：

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“刚性”发光软质材料：基于聚氧乙烯植物甾醇和离子液体的含L溶致液晶

由离子液体（IL）介导的溶致液晶（LLC）中构造的β-二酮ike化complex复合物的柔软材料以其出色的发光性能和稳定性而令人印象深刻。为了进一步改善其机械加工性能和发光性，本文引入聚氧乙烯植物甾醇（BPS- n）作为结构导向剂，通过掺杂在1-丁基-3-甲基咪唑鎓六氟磷酸盐中制备相对“刚性”的层状发光LLC。 β-二酮化im与不同咪唑鎓抗衡离子的配合物。由于BPS- n的疏溶剂固醇环结构，可以实现effective络合物的更有效的分离和封闭作用。因此获得了迄今为止报道的含euro的溶致组织的软材料的最长的荧光寿命和最高的量子效率。改变BPS- n的分子结构如果使用不同的氧乙烯链或具有不同烷基链长度的咪唑鎓抗衡离子掺杂的络合物，则层状LLC矩阵的间距和分散的络合物的位置变得可调。此类复合LLC的实测发光和流变性能显示出对甾醇分子提供的刚性和隔离能力的依赖性。还发现抗衡离子烷基链长度的增加会削弱LLC基质的封闭和隔离效果，因此显示出劣化的发光性能。掺杂BPS- n的增强的发光效率和稳定性有限责任公司反映出the络合物之间的出色隔离，因此减少了自淬灭过程。此处获得的结果表明了LLC矩阵的可设计性及其促进实现软材料的发光可调性的巨大潜力。