Jadrich R B, Bollinger J A, Lindquist B A, Truskett T M
McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712, USA.
Soft Matter. 2015 Dec 28;11(48):9342-54. doi: 10.1039/c5sm01832c.
Inverse methods of statistical mechanics are becoming productive tools in the design of materials with specific microstructures or properties. While initial studies have focused on solid-state design targets (e.g., assembly of colloidal superlattices), one can alternatively design fluid states with desired morphologies. This work addresses the latter and demonstrates how a simple iterative Boltzmann inversion strategy can be used to determine the isotropic pair potential that reproduces the radial distribution function of a fluid of amorphous clusters with prescribed size. The inverse designed pair potential of this "ideal" cluster fluid, with its broad attractive well and narrow repulsive barrier at larger separations, is qualitatively different from the so-called SALR form most commonly associated with equilibrium cluster formation in colloids, which features short-range attractive (SA) and long-range repulsive (LR) contributions. These differences reflect alternative mechanisms for promoting cluster formation with an isotropic pair potential, and they in turn produce structured fluids with qualitatively different static and dynamic properties. Specifically, equilibrium simulations show that the amorphous clusters resulting from the inverse designed potentials display more uniformity in size and shape, and they also show greater spatial and temporal resolution than those resulting from SALR interactions.
统计力学的逆方法正成为设计具有特定微观结构或性质材料的有效工具。虽然最初的研究集中在固态设计目标（如胶体超晶格的组装）上，但人们也可以设计具有所需形态的流体状态。这项工作关注后者，并展示了如何使用一种简单的迭代玻尔兹曼反演策略来确定各向同性的对势，该对势能再现具有规定尺寸的非晶团簇流体的径向分布函数。这种“理想”团簇流体的反演设计对势，在较大间距处具有宽吸引阱和窄排斥势垒，在定性上不同于通常与胶体中平衡团簇形成相关的所谓SALR形式，后者具有短程吸引（SA）和长程排斥（LR）贡献。这些差异反映了用各向同性对势促进团簇形成的不同机制，进而产生具有定性不同的静态和动态性质的结构化流体。具体而言，平衡模拟表明，由反演设计势产生的非晶团簇在尺寸和形状上表现出更高的均匀性，并且与由SALR相互作用产生的团簇相比，它们还表现出更高的空间和时间分辨率。
