Orientation-Controlled Ultralong Assembly of Janus Particles Induced by Bubble-Driven Instant Quasi-1D Interfaces

Constructing precisely oriented assemblies and exploring their orientation-dependent properties remain a challenge for Janus nanoparticles (JNPs) due to their asymmetric characteristics. Herein, we propose a bubble-driven instant quasi-1D interfacial strategy for the oriented assembly of JNP chains in a highly controllable manner. It is found that the rapid formation of templated bubbles can promote the interfacial orientation of JNPs kinetically, while the confined quasi-1D interface in the curved liquid bridge can constrain the disordered rotation of the particles, yielding well-oriented JNP chains in a long range. During the evaporation process, the interfacial orientation of the JNPs can be transferred to the assembled chains. By regulating the amphiphilicity of the JNPs, both heteraxial and coaxial JNP assemblies are obtained, which show different polarization dependences on light scattering, and the related colorimetric logic behaviors are demonstrated. This work demonstrates the great potential of patterned interfacial assembly with a manageable orientation and shows the broad prospect of asymmetric JNP assembly in constructing novel optoelectronic devices.

Automated summary

In this study, a bubble-driven instant quasi-1D interfacial strategy was proposed for the oriented assembly of Janus nanoparticle (JNP) chains. The rapid formation of templated bubbles promoted the interfacial orientation of JNPs kinetically, while the confined quasi-1D interface in the curved liquid bridge constrained the disordered rotation of particles, resulting in well-oriented JNP chains. By regulating the amphiphilicity of JNPs, heteraxial and coaxial JNP assemblies were obtained, which exhibited different polarization dependences on light scattering and demonstrated colorimetric logic behaviors. This work demonstrates the potential of patterned interfacial assembly and the prospect of asymmetric JNP assembly in constructing novel optoelectronic devices.