Fabrication and characterization of gradient refractive index plastic rods containing inorganic nanoparticles

A novel method was developed for the preparation of GRIN plastic rods containing inorganic nanoparticles. Silver nanoparticles were prepared by using W/O (water in oil) reversed micelle technique in the presence of bis(2-ethylhexyl) sulphosuccinate (AOT) surfactant. The effects of w values (w = [H₂O]/[AOT]), silver nitrate concentration, AOT/isooctane/H₂0 ratio, and initiator concentration on the nanoparticle size were investigated. Optical absorption spectra of the micellar samples were recorded on a spectrophotometer at room temperature in the range of 200-900 nm. The nanoparticle size was confirmed by TEM technique. To introduce the nanoparticles into the GRIN plastic rods, methyl methacrylate (MM A) was used instead of isooctane in the organic phase. Nanoparticles were found to increase the refractive index of plastic rods effectively. However, the existence of surfactant may cause the aggregation of nanoparticles leading to the occurrence of light scattering and becoming opaque. We estimated both real image transmission and the three dimensional refractive index distributions of the GRIN plastic rods prepared in this investigation. The results in this investigation suggest that nanoparticles could be used as a dopant to fabricate GRIN plastic rods and increase its refractive index effectively.