Pigment and nanofiller photoreactivity database

The service life and durability of nanocomposites containing fillers are affected by photocatalytic properties of these fillers, particularly narrow band gap metal oxides (NBMOs) such as titanium dioxide (TiO₂). When irradiated with ultraviolet flux, NBMOs produce electrons and other species that are capable of causing rapid degradation of organic materials with which they are in contact. Electrons and holes (positively charged species) migrate to the surface and react with species to generate various free radicals. Measurement science tools for characterizing TiO₂ photoreactivity using electron paramagnetic resonance (EPR) methods have been developed by the Engineering Laboratory (EL) at the National Institute of Standards and Technology (NIST) and a linkage between EPR measurements and current industrial methods has been established. A database of TiO₂ photoreactivity values and other data measured via the EPR methods and industrial assays has been compiled and will be accessed through a searchable software database in the NIST Standard Reference Database program??http://www.nist.gov/srd/index.cfm. The database provides fundamental photoreactivity data that can be used for product selection and development purposes to enable more reliable assessments of end-performance.