Sullivan Kyle T, Hayward Ryan C, Grason Gregory M
Department of Physics, <a href="https://ror.org/0072zz521">University of Massachusetts, Amherst</a>, Massachusetts 01003, USA.
Department of Chemical and Biological Engineering, <a href="https://ror.org/02ttsq026">University of Colorado, Boulder</a>, Colorado 80303, USA.
Phys Rev E. 2024 Aug;110(2-1):024602. doi: 10.1103/PhysRevE.110.024602.
In geometrically frustrated assemblies local intersubunit misfits propagate to intra-assembly strain gradients, giving rise to anomalous self-limiting assembly thermodynamics. Here we use theory and coarse-grained simulation to study a recently developed class of "curvamer" particles, flexible shell-like particles that exhibit self-limiting assembly due to the build up of curvature deformation in cohesive stacks. To address a generic, yet poorly understood aspect of frustrated assembly, we introduce a model of curvamer assembly that incorporates both intraparticle shape deformation as well as compliance of interparticle cohesive gaps, an effect we can attribute to a finite range of attraction between particles. We show that the ratio of intraparticle (bending elasticity) to interparticle stiffness not only controls the regimes of self-limitation but also the nature of frustration propagation through curvamer stacks. We find a transition from uniformly bound, curvature-focusing stacks at small size to gap opened, uniformly curved stacks at large size is controlled by a dimensionless measure of inter- versus intracurvamer stiffness. The finite range of interparticle attraction determines the range of cohesion in stacks that are self-limiting, a prediction which is in strong agreement with numerical studies of our coarse-grained colloidal model. These predictions provide critical guidance for experimental realizations of frustrated particle systems designed to exhibit self-limitation at especially large multiparticle scales.
在几何受挫的组装体中，局部亚基间的错配会传播为组装体内的应变梯度，从而产生反常的自限性组装热力学。在此，我们运用理论和粗粒化模拟来研究一类最近开发的“弯曲体”粒子，即柔性壳状粒子，它们由于在凝聚堆叠中曲率变形的积累而呈现出自限性组装。为了探讨受挫组装中一个普遍但理解不足的方面，我们引入了一个弯曲体组装模型，该模型既包含粒子内形状变形，也包含粒子间凝聚间隙的柔顺性，我们可将这种效应归因于粒子间有限范围的吸引力。我们表明，粒子内（弯曲弹性）与粒子间刚度的比值不仅控制自限性的状态，还控制通过弯曲体堆叠的受挫传播的性质。我们发现，从小尺寸时均匀结合、曲率聚焦的堆叠到大尺寸时间隙打开、均匀弯曲的堆叠的转变，由弯曲体间与弯曲体内刚度的无量纲度量控制。粒子间吸引力的有限范围决定了自限性堆叠中的凝聚范围，这一预测与我们粗粒化胶体模型的数值研究高度一致。这些预测为旨在在特别大的多粒子尺度上表现出自限性的受挫粒子系统的实验实现提供了关键指导。
