I read many papers mixing tio2 with plastics.
I think even for a easier result , titanium dioxide can be mixed with salt and can be used to make insitu lenses as us soldiers produce their bullets from snow or sand at dan brown.
Titanium Dioxide Crystal Types
Titanium dioxide is manufactured in two crystal forms: anatase and rutile.
Both anatase and rutile TiO2 produce high opacity due to their high refractive index in comparison with extenders, fillers and early pigments. See Figure 4.1.
However, although anatase TiO2 was the first to be produced commercially, and represented a step-change in optical performance over the pigments that preceded it, the rutile form of TiO2 offers still higher opacity and durability.
In fact, examination of the basic properties of the two crystal forms shows several differences – in specific gravity, hardness, refractive index, and relative tint strength. The oil absorption of commercial anatase and rutile pigments also varies – in part due to the different types of surface treatment applied to them. See Figure 4.2 (anatase) and Figure 4.3 (rutile) for crystal properties.
Although both are 'white' pigments, they exhibit differences in tone with anatase pigments producing a bluer tone than rutile pigments. The reason for this can be found in their somewhat different reflectance curves across the visible and near visible spectrum. See Figure 4.4 for anatase and rutile reflectance curves.
Thus, rutile TiO2 reflects radiation slightly better than anatase in all but the very blue end of the visible spectrum and in the ultra-violet region and is therefore slightly brighter. But because anatase TiO2 absorbs less light at the blue end of the spectrum, it has a visibly bluer tone than rutile pigment. It should be noted that the mass tone of either anatase or rutile pigments are also influenced by their purity with coloring ion impurities such as iron, niobium, vanadium and chromium having a significant effect on the color of a pigment.
Because the rutile form absorbs more UV radiation, it further reduces the amount of energy available to degrade the binder system and provides relatively better durability to a system than anatase. However, the durability of rutile TiO2 pigment may be significantly improved by the addition of surface treatment.
Although the difference in refractive index gives rutile pigments up to 15% opacity benefit over anatase pigments, the bluer tone and lower hardness of anatase pigments are beneficial in some applications, especially where low abrasivity may be an issue. Thus anatase pigments were originally the preferred choice for paper filling and coating and also for delustering of synthetic fibers, where the color of the application may degraded by abrasion of metal during frequent rubbing contact with machinery during processing.
Where the highest possible optical efficiency and durability are required, rutile pigments are superior. In practice, virtually all paints and plastic applications are now pigmented with surface treated rutile pigments, with the coating specifically designed to maximize the performance properties required. Specially treated rutile pigments are also used in paper laminate applications where high opacity and good light stability are essential
