Preparation of monodispersed polystyrene microspheres and self-assembly of photonic crystals for structural colors on polyester fabrics

Monodispersed polystyrene (PS) microspheres with perfect sphericity and the spherical diameter ranging from 200 to 400 nm were prepared by soap-free emulsion polymerization. The spherical size of PS microspheres can be regulated by controlling the styrene concentration, potassium persulfate concentration, and polymerization time. The monodispersed PS microspheres were self-assembled by gravity into photonic crystals on polyester fabrics to generate bright structural colors. Scanning electron microscopy (SEM) observation and crystallographic analysis confirmed a face-centered cubic structure (FCC structure) of the photonic crystals. The structural color of the photonic crystals is governed by the photonic band gap dependent upon the viewing angle and the size of PS microspheres. The resultant polyester fabrics with the photonic crystals showed bright structural colors changing with the viewing angle, displaying a biomimetic variable color effect on the textiles.