Dynamic interfacial trapping of Janus nanorod aggregates in polymer blends*

Taking advantage of both shape and chemical anisotropy on the same nanoparticle offers rich plasmonic and self-assembly possibilities for nanotechnology. Combining Dissipative Particle Dynamics and Discrete Dipole Approximation calculations, the directed assembly of Janus nanorod aggregates in polymer blends has been assessed, along with the optical properties resulting thereof. Janus rods become kinetically-trapped and exhibit either parallel or antiparallel alignment with respect to their long axis. This depends on several factors that can be precisely tuned. Ultimately, two different aggregate structures result from rod tumbling that are not observed under quiescent conditions: monolayer-like aggregates exhibiting trapped rods with antiparallel configuration; and stacked nanorod arrays similar to superlattice sheets. Hence, the present study offers fundamental insight into relevant parameters governing the directed assembly of Janus nanoparticles at an interfacial level as well as an assessment of the potentially novel optical applications deriving from the resulting aggregate structures, such as peculiar displays and sensors.