Patchy Nanoparticle Synthesis and Self-Assembly

Abstract

Biological building blocks (i.e., proteins) are encoded with the information of target structure into the chemical and morphological patches, guiding their assembly into the levels of functional structures that are crucial for living organisms. Learning from nature, researchers have been attracted to the artificial analogues, “patchy particles,” which have controlled geometries of patches that serve as directional bonding sites. However, unlike the abundant studies of micron-scale patchy particles, which demonstrated complex assembly structures and unique behaviors attributed to the patches, research on patchy nanoparticles (NPs) has remained challenging. In the present chapter, we discuss the recent understandings on patchy NP design and synthesis strategies, and physical principles of their assembly behaviors, which are the main factors to program patchy NP self-assembly into target structures that cannot be achieved by conventional non-patched NPs. We further summarize the self-assembly of patchy NPs under external fields, in simulation, and in kinetically controlled assembly pathways, to show the structural richness patchy NPs bring. The patchy NP assembly is novel by their structures as well as the multicomponent features, and thus exhibits unique optical, chemical, and mechanical properties, potentially aiding applications in catalysts, photonic crystals, and metamaterials as well as fundamental nanoscience.

Symmetry-Broken Patches on Gold Nanoparticles through Deficient Ligand Exchange

“…It makes our method simple, general, and highly reproducible. We expect that it opens new doors to design symmetry-broken PGPNs as unique building blocks for their hierarchical self-assembly …”

Inverse design of triblock Janus spheres for self-assembly of complex structures in the crystallization slot via digital alchemy

“…For example, particles can be designed that self-assemble into open structures, [5][6][7][8] and these patchy interactions are often simpler (e.g., smoother functional form and without an excessive number of wells) to achieve both computationally and experimentally than isotropic but oscillatory pair potentials that also selfassemble open structures. [9][10][11][12] New techniques in patchy particle synthesis are making ever more complex patch patterns possible, 13,14 bringing ever closer the promise of patchy particles for colloidal matter on demand. However, the high degree of tailorability of patchy particles is a double-edged sword.…”

Patchy metal nanoparticles with polymers: controllable growth and two-way self-assembly

“…To this end, one area that has drawn increasing interest is the selective ligand modification of metal NPs to form the so-called patchy NPs. 20,21 Ligands can pattern the surface of NPs through a number of methods, including templated surface modification, 22,23 sitespecific grafting, [24][25][26] phase separation of mixed ligands, [27][28][29][30][31] and hydrophobicity-driven phase segregation. 32,33 As a postsynthetic method, surface ligands pattern the surface of metal NPs having pre-designed nanostructures without re-designing and re-synthesizing of NPs.…”