Hollow Microspheres of SiO2/PMMA Nanocomposites: Preparation and Their Application in Light Diffusing Films

This paper presented a facile method to prepare the silica/poly (methyl methacrylate) (SiO2/PMMA) nanocomposite hollow microspheres (NHSs) which were firstly applied to fabricate the light diffusion films with high transmittance and high haze simultaneously. The SiO2/PMMA NHSs were prepared via in situ diffusion of polymeric core into the voids of inorganic shell under strong electrostatic attraction. The hollow morphologies of the microspheres were studied under the help of transmission electron microscope and scanning electronic microscope. The formation process of these NHSs could be elucidated using a mechanism similar to the Kirkendall effect. These NHSs were firstly used to produce light diffusion films by blending with polyacrylate latex. The new kind of light diffusion films with micro-nano structure were built by casting the SiO2/PMMA NHSs/polyacrylate coatings on optical-grade PET films. The transmittance and haze value of the light diffusion films were tested by a haze meter and application on a LED lamp. As a result, the coating films with NHSs had the best light diffusion properties compared to those films with no spheres or nanocomposite solid microspheres, which indicated that the light diffusion films with NHSs were promisingly applied in LED illumination, photoelectric devices and large area LCD.