Hoshino Taiki, Nakayama Masanari, Hosokawa Yoshihiro, Mochizuki Kohei, Kajiyama Satoshi, Kohmura Yoshiki, Kato Takashi
International Center for Synchrotron Radiation Innovation Smart (SRIS), Tohoku University 2-1-1 Katahira, Aoba-ku Sendai 980-8577 Japan
RIKEN SPring-8 Center 1-1-1, Kouto, Sayo-cho, Sayo-gun Hyogo 679-5148 Japan.
Nanoscale Adv. 2023 May 19;5(14):3646-3654. doi: 10.1039/d3na00183k. eCollection 2023 Jul 11.
Self-organized supramolecular assemblies are widespread in nature and technology in the form of liquid crystals, colloids, and gels. The reversible nature of non-covalent bonding leads to dynamic functions such as stimuli-responsive switching and self-healing, which are unachievable from an isolated molecule. However, multiple intermolecular interactions generate diverse conformational and configurational molecular motions over various time scales in their self-assembled states, and their specific dynamics remains unclear. In the present study, we have experimentally unveiled the static structures and dynamical behaviors in columnar colloidal liquid crystals by a coherent X-ray scattering technique using refined model samples. We have found that controlling the size distribution of the colloidal nanoplates dramatically changed their static and dynamic properties. Furthermore, the resulting dynamical behaviors obtained by X-ray photon correlation spectroscopy have been successfully decomposed into multiple distinct modes, allowing us to explore the dynamical origin in the colloidal liquid-crystalline state. The present approaches using a columnar liquid crystal may contribute to a better understanding of the dynamic nature of molecular assemblies and dense colloidal systems and bring valuable insights into rational design of functional properties of self-assembled materials such as stimuli-responsive liquid crystals, self-healing gels, and colloidal crystals. For these materials, the motion of constituent particles and molecules in the self-assembled state is a key factor for structural formation and dynamically responsive performance.
自组装超分子聚集体以液晶、胶体和凝胶的形式广泛存在于自然界和技术领域。非共价键的可逆性导致了诸如刺激响应切换和自我修复等动态功能，而这些功能是单个分子无法实现的。然而，多种分子间相互作用在其自组装状态下的不同时间尺度上产生了多样的构象和构型分子运动，其具体动力学仍不明确。在本研究中，我们通过使用精制模型样品的相干X射线散射技术，实验揭示了柱状胶体液晶中的静态结构和动力学行为。我们发现，控制胶体纳米片的尺寸分布会显著改变其静态和动态性质。此外，通过X射线光子相关光谱获得的动力学行为已成功分解为多个不同模式，这使我们能够探索胶体液晶态的动力学起源。使用柱状液晶的当前方法可能有助于更好地理解分子聚集体和致密胶体系统的动态性质，并为合理设计自组装材料（如刺激响应液晶、自我修复凝胶和胶体晶体）的功能特性带来有价值的见解。对于这些材料，自组装状态下组成颗粒和分子的运动是结构形成和动态响应性能的关键因素。
