979307 - Use of TiO2 Enhanced Photocatalytic Construction Materials That Promote the Natural Oxidation of Vehicular-sourced Pollution and to Mitigate Heat Sinks in the Critical Roadway Microenvironment

In 2017 and 2018, PTI applied the first field tests for durable TiO2 solutions in Greenville (SC) and Orlando (FL). The technological breakthrough combined proven surface penetrating pavement preservation compounds, long utilized in Orlando and elsewhere, fortified with photocatalyst grade TiO2, to impregnate pavements with the natural pollution-reducing and heat reflecting material. The PTI technique provides both a method for sustainable TiO2 delivery into pavement wearing-course depth and at cost-effective “retrofit” economics. The practice promotes an efficient and scalable application for solar-based, direct capture technology for O3 precursors in the near-road environment.

Titanium is an amazing material. It is as strong as steel, yet a fraction of its weight and much more durable. TiO2 is a natural mineral whose atypical chemical properties have led to a diverse range of commercial and industrial uses from whitening additives in paints to food coloring, candy coatings, toothpaste and reflective sunscreens, etc., or as surface ‘wetting’ (i.e., hydrophilic) and anti-fogging agents, or as photo-reactive chemical catalysts.
As a photocatalyst, TiO2 is a multifaceted photo-responsive material rapidly gaining increased scientific and commercial interest for near-roadway MEs as it may advance a host of positive environmental benefits, including:

Depolluting near-pavement air (or water) cleaning applications, where TiO2 reacted surfaces are able to oxidize a variety of pollutants and contaminants such as those emitted by vehicles, especially NOx and VOCs, reducing ozone pollution and mitigating acid rain formation.

“Cool Pavement” applications where TiO2 treated surfaces provide a solar-reflective top boundary, which lessens pavement related radiative forcing (RF) by reducing the convective re- release or emissivity of solar radiation that leads to the undesired UHI effects and enhances the life-cycle assessment of pavements by slowing-down oxidation.

Super-Hydrophilic surfaces, which provide a rapid water-desorbing pavement, which is self- cleaning to remove contaminants (e.g., mold) and staining; and is indicated for inclement weather- related safety (rain displacing; ice inhibiting) improvements for roadways.