Monolayer polystyrene micro-spheres array master derived by spin-coating method for UV nanoimprint.

Polystyrene micro-spheres aqueous suspensions were obtained by an emulsifier-free polymerization method. Fourier transform infrared spectroscopy and laser particle size distribution were used to characterize the colloidal solutions. Results indicate that the polystyrene micro-spheres colloidal solution has a good dispersion and the micro-spheres have a uniform size and smooth surface. The as-prepared polystyrene micro-spheres colloidal solution was spun onto glass substrates and then the coated sample was heated at 70 degrees C for 1 h to form close-packed monolayer polystyrene microspheres arrays, which are used as a master. Scanning electron microscopy was used to observe the morphological properties of the polystyrene micro-spheres array. A relative good result can be easily obtained by a spinning speed of 2000 rpm for 30 second, when the solution concentration is around 10 wt.%. Furthermore, the polydimethylsiloxane soft mold was replicated from the-fabricated polystyrene micro-spheres array master and was then imprinted onto the photosensitive hybrid film under UV-irradiation and thus the micro-lens arrays built in the photosensitive hybrid sol-gel film were obtained.