In order to generate high refractive indices, one approach is the use of composite polymers using inorganic nanoparticles. To avoid scattering effects, the nanoparticles, such as oxide nanoparticles, have to be small compared to the wavelength the material is used for. In order to avoid any agglomeration, nanoparticles and matrix materials have to be extremely well adjusted. Therefore, the nanoparticles are functionalized on the surface. This functionalization results in a decrease of effective refractive index and sometimes provide ageing issues such as yellowing effects when stressed thermally and/or by blue or UV light.
CeSMA has collected a lot of know-how in order to create well processable composites with low haze and excellent ageing properties. Selection of nanoparticles, processing, adaptation of the matrix material and characterization of the composite are all part of the services offered by CeSMA.
Not as sensitive as for optical applications but from a physical point of view the same function is the use of high-k nanoparticles for high-k dielectrics.