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Self‐assembly of inorganic nanoparticles (NPs) is an essential tool for constructing structured materials with a wide range of applications. However, achieving ordered assembly structures with externally programmable properties in binary NP systems remains challenging. In this work, we assemble binary inorganic NPs into hierarchically pH‐responsive alternating copolymer‐like nanostructures in an aqueous medium by engineering the interparticle electrostatic interactions. The polymer‐grafted NPs bearing opposite charges are viewed as nanoscale monomers ("nanomers"), and copolymerized into alternating nano‐copolymers (ANCPs) driven by the formation of interparticle "bonds" between nanomers. The resulting ANCPs exhibit reversibly responsive "bond" length (i.e. the distance between nanomers) in response to the variation of pH in a range of ~7–10, allowing precise control over the surface plasmon resonance of ANCPs. Moreover, specific interparticle "bonds" can break up at pH≥11, leading to the dis‐assembly of ANCPs into molecule‐like dimers and trimers. These dimeric and trimeric structures can reassemble to form ANCPs owing to the resuming of interparticle "bonds", when the pH value of the solution changes from 11 to 7. The hierarchically responsive nanostructures may find applications in such as biosensing, optical waveguide, and electronic devices. [ABSTRACT FROM AUTHOR]

Colloidal molecules (CMs) are precisely defined assemblies of nanoparticles (NPs) that mimic the structure of real molecules, but externally programming the precise self‐assembly of CMs is still challenging. In this work, we show that the photo‐induced self‐assembly of complementary copolymer‐capped binary NPs can be precisely controlled to form clustered ABx or linear (AB)y CMs at high yield (x is the coordination number of NP‐Bs, and y is the repeating unit number of AB clusters). Under UV light irradiation, photolabile p‐methoxyphenacyl groups of copolymers on NP‐A*s are converted to carboxyl groups (NP‐A), which react with tertiary amines of copolymers on NP‐B to trigger the directional NP bonding. The x value of ABx can be precisely controlled between 1 and 3 by varying the irradiation duration and hence the amount of carboxyl groups generated on NP‐As. Moreover, when NP‐A* and NP‐B are irradiated after mixing, the assembly process generates AB clusters or linear (AB)y structures with alternating sequence of the binary NPs. This assembly approach offers a simple yet non‐invasive way to externally regulate the formation of various CMs on demand without the need of redesigning the surface chemistry of NPs for use in drug delivery, diagnostics, optoelectronics, and plasmonic devices. [ABSTRACT FROM AUTHOR]

Controllable self-assembly of copolymers in solutions offers an effective tool for constructing functional nanostructures. However, achieving the stepwise assembly of copolymers in solutions remains challenging. In this study, we report the fabrication of cylindrical microstructures through the stepwise self-assembly of bottlebrush random copolymers (BBRPs) in solutions. The BBRPs were synthesized via a combination of "grafting-through" and "grafting-from" strategies. The assembly of BBRPs yielded spherical micelles in a mixture of dioxane and water, which further transformed into uniform cylindrical microstructures by dialyzing the solution against water. The cylinders could be obtained within a relatively large range of parameters, such as length ratios of hydrophilic/hydrophobic blocks, volume fractions of water, and copolymer concentrations. This work provides new insights into the assembly behavior of BBRPs and the preparation of cylindrical structures for applications in such as templated synthesis of hybrid materials. [ABSTRACT FROM AUTHOR]

Zhihong Nie, Yutao Sang, and their colleagues have published a research article in Angewandte Chemie International Edition on the photo-induced self-assembly of copolymer-capped nanoparticles into colloidal molecules. They use photolabile copolymer ligands to control the self-assembly of binary nanoparticles A and B into clustered ABx or linear (AB)y structures. This research demonstrates the ability to generate colloidal molecules with precise structures using UV light. [Extracted from the article]