Light diffusing films fabricated by strawberry-like PMMA/SiO₂ composite microspheres for LED application.
This paper presents a facile method to fabricate volumetric light diffusing films with high transmittance and haze simultaneously by mimicking the micro- and nanostructure of compound eyes. Strawberry-like polymethyl methacrylate/SiO2 composite microspheres were first prepared via the electrostatic attraction between positively charged PMMA spheres and negatively charged SiO2 nanoparticles, and further blended with polyacrylate latex to produce light diffusing coatings. A novel light diffusing film with hemispherical surface was built by casting the light diffusing coatings on optical-grade PET film. Effects of the sizes of PMMA spheres and SiO2 nanoparticles on the optical properties of light diffusing film were investigated by a haze meter and application on a LED lamp. The best result (transmittance 94.6% and haze 84.2%) was achieved for the strawberry-like composite microspheres based on 1 μm PMMA spheres and 50 nm SiO2 nanoparticles. The light-diffusing mechanism of the strawberry-like microspheres in the film was discussed.
Department of Materials Science and Advanced Coatings Research Center of Education Ministry of China, Fudan University, Shanghai 200433, China.
Shuang
S
Guo
Department of Materials Science and Advanced Coatings Research Center of Education Ministry of China, Fudan University, Shanghai 200433, China.
Shuxue
S
Zhou
Department of Materials Science and Advanced Coatings Research Center of Education Ministry of China, Fudan University, Shanghai 200433, China.
Huijing
H
Li
Department of Materials Science and Advanced Coatings Research Center of Education Ministry of China, Fudan University, Shanghai 200433, China. Electronic address: youbo@fudan.edu.cn.
Bo
B
You
Colloidal silica; LED light diffusing film; PMMA spheres; Strawberry-like microspheres