College of Chemistry, Sichuan University, Chengdu 610064, China.
Soft Matter. 2023 Feb 15;19(7):1312-1329. doi: 10.1039/d2sm01402e.
Extensive studies so far have indicated that chirality, anisotropic interactions and spatial confinement play important roles in collective dynamics in active matter systems. However, how the overall interplay of these crucial factors affects the novel phases and macroscopic properties remains less explored. Here, using Langevin dynamics simulations, we investigate the self-organization of a chiral active system composed of amphiphilic Janus particles, where the embedded anisotropic interaction orientation is assumed to be either the same or just opposite to the direction of active force. A wealth of dynamic phases are observed including formation of phase separation, clustering state, homogeneous state, spiral vortex flow, swarm and spatiotemporal oscillation. By tuning self-propelled angular speed and anisotropic interaction strength, we identify the non-equilibrium phase diagrams, and reveal the very non-trivial modulation of both vortex and swarm patterns. Intriguingly, we find that strong chirality-alignment-confinement coupling yields a self-driven spatial and temporal organization periodically oscillating between a counterclockwise vortex and a clockwise one. Our work provides a new understanding of the novel self-assembly arising in such a confined system and enables new strategies for achieving ordered dynamic structures.
迄今为止的广泛研究表明，手性、各向异性相互作用和空间限制在活性物质系统的集体动力学中起着重要作用。然而，这些关键因素的总体相互作用如何影响新的相和宏观性质，仍有待进一步探索。在这里，我们使用朗之万动力学模拟研究了由两亲性 Janus 粒子组成的手性活性系统的自组织，其中嵌入的各向异性相互作用方向被假定为与活性力的方向相同或相反。观察到丰富的动态相，包括相分离、聚类状态、均匀状态、螺旋涡旋流、群集和时空振荡的形成。通过调整自推进角速度和各向异性相互作用强度，我们确定了非平衡相图，并揭示了涡旋和群集模式的非常非平凡调制。有趣的是，我们发现强手性排列限制耦合产生了一种自驱动的时空组织，在逆时针涡旋和顺时针涡旋之间周期性地振荡。我们的工作为这种受限系统中出现的新自组装提供了新的理解，并为实现有序动态结构提供了新的策略。
