A theoretical study into the hiding power of white TiO2-free coatings

 
Pigments that could replace titanium dioxide are desired, but not easily identified. In this work, alternatives were evaluated in silico (by computer simulations) rather than in paint. To do this, the maximum theoretical hiding power of non-absorbing, potentially opacifying substances was calculated. Normal (massive) particles were assessed, but also hollow versions were evaluated. For this, the particle sizes were optimized for maximum scattering. It was then determined how the performance in hiding power would compare to that of titanium dioxide (in paints below the critical PVC). The calculations show that TiO2¬ is still by far the most effective opacifier. For comparable hiding power at equal PVC and without additional labelling, an at least 4 times thicker coating layer would be required. This would lead to a considerable increase in labor, raw material use and ecological footprint.