10/31/2022 0 Comments Core shell at![]() However, despite their interfacial core–corona morphology, we note that for pure microgels ( 44, 45) and typical core–microgel shell systems ( 46– 49), only an isostructural hexagonal non–close packed to hexagonal close-packed transition is observed. Since this initial discovery, many theoretical reports have shown that dozens of different structures can originate from simple spherical particles interacting via such Jagla-like potentials, including honeycombs, or quasicrystals of various symmetries for relative small shell-to-core ratios ( r 1 / r 0 ≲ 2 ) ( 26– 30), as well as defined particle clusters and complex chains phases at higher shell-to-core ratios ( r 1 / r 0 ≳ 2 ) ( 24, 31– 35). In particular, the minimum energy phase in such core–shell systems is determined by three parameters: the ratio of the shell-to-core diameter ( r 1 / r 0 ), the shape of the soft repulsive potential, expressed by the parameter g, and the area fraction of the system ( η), which determines the total amount of shell overlap ( 23, 27). 1, provides flexibility to tune the resultant self-assembly behavior. Jagla further showed that the generic potential, shown in Fig. The formation of such counterintuitive phases results from the competition between the two length scales in the interaction: when the core–shell particles are compressed such that their shells begin to touch, the system can minimize its energy by fully overlapping neighboring shells in some directions in order to prevent the overlap of shells in other directions ( 24– 26). In 1998, Jagla showed that a simple addition of a soft repulsive shell surrounding a hard sphere introduces a second length scale in the interaction potential, which allows for the creation of nonhexagonal minimum energy configurations (MECs) such as chains, squares, and rhombic phases ( 23). The possibility to control the interaction potential via the interfacial morphology provides a framework to realize structural features with unprecedented complexity from a simple, one-component system.Īn elegant solution to directly decouple particle shape from the resulting self-assembled phases has been theoretically proposed decades ago. By comparing theory, simulation, and experiment, we narrow the Jagla g-parameter of the system to between 0.9 and 2. ![]() The experimental phase behavior is accurately reproduced by Monte Carlo simulations and minimum energy calculations, suggesting that the interfacial assembly interacts via a pairwise-additive Jagla-type potential. Upon interfacial compression, the resulting core–shell particles arrange in well-defined dimer, trimer, and tetramer lattices before transitioning into complex chain and cluster phases. We controllably grow such shells by iniferter-type controlled radical polymerization. We find that core–shell particles consisting of a silica core surface functionalized with a noncrosslinked polymer shell efficiently spread at a liquid interface to form a two-dimensional polymer corona surrounding the core. Here, we capitalize on the distinct interfacial morphology of soft particles to design two-dimensional assemblies with structural complexity. Despite the elegance of this approach, its experimental realization has remained largely elusive. Based on such Jagla potentials, a wide variety of phases including cluster lattices, chains, and quasicrystals have been theoretically discovered. More than two decades ago, Jagla demonstrated that core–shell particles with two interaction length scales can form complex, nonhexagonal minimum energy configurations. ![]() However, the prevalence of hexagonal symmetries in such self-assembling systems limits its structural versatility. The two-dimensional self-assembly of colloidal particles serves as a model system for fundamental studies of structure formation and as a powerful tool to fabricate functional materials and surfaces. ![]()
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