A versatile dispersion of colloidal silica in a difunctional acrylate monomer for the use in adhesive and electronic applications. The silica phase consists of surface-modified, synthetic SiO2-spheres of very small size (Ø 20 nm) and narrow particle size distribution. Despite the high SiO2- content of 50 wt%, NANOCRYL® A 210 is highly transparent, low viscous and shows no sedimentation due to the agglomerate-free dispersion of the nanoparticles in the acrylate.