The results of the conversion of nanoparticle volumes to quasi-molecular weights are summarized in Table 3. For the smallest particles up to particle diameters of 2 nm molecular weights and diffusion coefficients were calculated in the range of common plastics additives. Then, with further increasing particle diameter molecular weights increase and diffusion coefficients decrease exponentially. For a particle with 10 nm in diameter, which is a small but realistic size for primary nanoparticles, an extremely low diffusion coefficient of 1.1E35 cm2 s1 was calculated. This diffusion coefficient results in an extreme low mobility of the nanoscale migrant that was never observed from any other additive in any polymer matrix.