Aoyagi Noboru, Motokawa Ryuhei, Okumura Masahiko, Ueda Yuki, Saito Takumi, Nishitsuji Shotaro, Taguchi Tomitsugu, Yomogida Takumi, Sazaki Gen, Ikeda-Ohno Atsushi
Advanced Science Research Centre (ASRC), Japan Atomic Energy Agency (JAEA), Tokai-mura, Ibaraki, 319-1195, Japan.
Materials Sciences Research Centre (MSRC), Japan Atomic Energy Agency (JAEA), Tokai-mura, Ibaraki, 319-1195, Japan.
Commun Chem. 2024 Jun 12;7(1):128. doi: 10.1038/s42004-024-01199-y.
Dissipative structures often appear as an unstable counterpart of ordered structures owing to fluctuations that do not form a homogeneous phase. Even a multiphase mixture may simultaneously undergo one chemical reaction near equilibrium and another one that is far from equilibrium. Here, we observed in real time crystal seed formation and simultaneous nanocrystal aggregation proceeding from Ce complexes to CeO nanoparticles in an acidic aqueous solution, and investigated the resultant hierarchical nanoarchitecture. The formed particles exhibited two very different size ranges, resulting in further pattern formation with opalescence. The hierarchically assembled structures in solutions were CeO colloids, viz. primary core clusters (1-3 nm) of crystalline ceria and secondary clusters (20-30 nm) assembled through surface ions. Such self-assembly is widespread in multi-component complex fluids, paradoxically moderating hierarchical reactions. Stability and instability are not only critical but also complementary for co-optimisation around the nearby free energy landscape prior to bifurcation.
由于波动不会形成均匀相，耗散结构通常表现为有序结构的不稳定对应物。即使是多相混合物也可能同时在接近平衡的状态下进行一种化学反应，以及在远离平衡的状态下进行另一种化学反应。在这里，我们实时观察到在酸性水溶液中从铈络合物到CeO纳米颗粒的晶种形成和同时发生的纳米晶体聚集，并研究了由此产生的分级纳米结构。形成的颗粒呈现出两个非常不同的尺寸范围，导致进一步形成具有乳光的图案。溶液中的分级组装结构是CeO胶体，即结晶二氧化铈的初级核心簇（1-3纳米）和通过表面离子组装的次级簇（20-30纳米）。这种自组装在多组分复杂流体中很普遍，矛盾的是，它缓和了分级反应。稳定性和不稳定性不仅至关重要，而且在分叉之前围绕附近的自由能景观进行共同优化时是互补的。
