Pressure sensitive adhesives comprising an acrylate polymer and surface-modified nanoparticles are described. The surface-modified nanoparticles comprise a nanoparticle having a silica surface and surface modifying groups covalently attached to the silica surface. At least one surface-modifying group is a polymeric silane surface modifying group. At least one surface-modifying group is a non-polymeric silane surface modifying group. Methods of preparing such adhesives, including their exposure to UVA and UVC radiation are also described.
