A new method for patterning azopolymer thin film surfaces

Abstract

Abstract:We present a simple bottom-up approach via an incoherent unpolarized illumination and the choice of a solvent-droplet-induced-dewetting method to photoinducenano doughnuts on the surface of azopolymer thin films. We demonstrate that doughnut-shaped nanostructures can be formed and tailored with a wide range of typical sizes, thus providing a rich field of applications using surface photo-patterning. Furthermore, due to the presence of highly photoactive azobenzene derivative in the material, illumination of these nanostructures by a polarized laser light shows the possibility of a further growth and reshaping opening the way for fundamental studies of size-dependent scaling laws of optical properties and possible fabrication of nano-reactor or nano-trap patterns.

Regulating Surface Topography of Liquid‐Crystalline Polymers by External Stimuli

“…[ 7 ] Then, a method of solvent‐induced dewetting has been developed to prepare ring‐shaped nanostructures on the surface of azobenzene‐containing films. [ 98 ] After dropping the solvent on the film surface, one incoherent white light beam was used to produce a photoinduced mass transport in film. As shown in Figure a, ring‐shaped nanostructures with diameters ranged from 150 to 500 nm were dispersed randomly on the film surface.…”

“…Reproduced with permission. [ 98 ] Copyright 2017, Elsevier. d) Schematic illustration of the formation of hierarchical stripes.…”

“…[99] For the primary stripes, it is easy to modulate by changing the moving distance and the stopping time of the lower substrate. For the secondary stripes, the influence of solution concentration and moving speed of lower substrate on the [98] Copyright 2017, Elsevier. d) Schematic illustration of the formation of hierarchical stripes.…”

“…c) AFM images of typical topography after 10 min LPL illumination. Reproduced with permission [98]. Copyright 2017, Elsevier.…”

Photonic applications of azobenzene molecules embedded in amorphous polymer

“…If azomaterials properties are coupled with other fabrication techniques, micro/nano structures of different shape and size can be realized [11,134,135] e.g. parallel groves [32,107,112,136], array of microporous [137][138][139][140][141] and hemispherical caps [142,143], whose geometry can be successively modified. Indeed, this technique allows to produce very sophisticated micro/nanoarchitecture that would be difficult to attain with other methods [12,107,144,145].…”