Photo-controllable self-assembly of azobenzene-decorated nanoparticles in bulk: Computer simulation study

We study the photo-controllable self-assembly of the azobenzene-functionalised nanoparticles using coarse-grained molecular dynamics simulations. With no illumination applied, a monodomain smectic morphology is formed only via cooling the isotropic system at sufficiently slow rate. Upon irradiation with appropriate wavelength and intensity, the azobenzenes undergo trans-eis-trans photoisomerisation cycles which unlock the interdomain links and induce uniaxial orientation of domains with their local director perpendicular to the polarisation axis of irradiation. As demonstrated by the simulations, this transition can spead-up essentially the self-assembly of decorated nanoparticles from the isotropic to the monodomain smectic phase, both via gradual cooling down and via quenching in a broad temperature interval below the smectic-isotropic transition.