Self-Assembly of Single Chain Janus Nanoparticleswith Tunable Liquid Crystalline Properties from Stilbene-ContainingBlock Copolymers

Functional particles self-assembled from polymer single chain nanoparticles have potential applications in various fields, but functionality incorporation is difficult due to their ultrasmall sizes. Here, the preparation and self-assembly of amphiphilic polymer single chain Janus nanoparticles (SCJNPs) with tunable liquid crystalline (LC) properties are reported via intrachain photo-cross-linking stilbene-containing amphiphilic block copolymers (BCPs). The cross-linking degree can be controlled by varying UV irradiation time, which affects the LC properties and the size of the resulting SCJNPs accordingly. The self-assembly behavior of the LC-SCJNPs in solution was further investigated systematically. The morphology transition from nonspherical assemblies, including tubular, doughnut-like, and saddle-shaped, to spherical nanoparticles was observed by changing UV irradiation time and the composition of BCPs. Furthermore, the assemblies display a smectic phase with clear ordering stripes under TEM observati...