Date of Award
Chemistry and Biochemistry
Sergiu M. Gorun, Ph.D
James E. Hanson, Ph.D
Wyatt R. Murphy, Ph.D
Photocatalyst, Self-cleaning coating, Singlet oxygen, Phthalocyanine, Titanium dioxide, visible light
A new photocatalytic composite powder incorporated into a siloxane epoxy polymer has been shown to yield a highly efficient self-cleaning coating. The composite, which makes greater use of light in the visible/near-infrared (NIR) region, was prepared by coating a nano-particle photocatalytic TiO2 with 3% w/w of F64PcZn photosensitizer resulting in a dark green powder. The F64PcZn/P25 TiO2 composite exhibited a greater photo-induced degradation of methyl red, a model surface contaminant, compared to traditional nano-particle photocatalytic TiO2. Singlet oxygen (1Δg 1O2), generated form the F64PcZn, is believed to be the primary species responsible for the observed photo-activity. The durability of the coating was evaluated by electrochemical impedance spectroscopy (EIS) due to the potential for unwanted photo-oxidation of the polymer by the photocatalytic material. After 11 weeks of atmospheric sunlight exposure, the coating containing the composite displayed a small drop in impedance value but still remained >10 GOhm cm2, indicating the formation of a strong barrier that is able to protect the underlying metal surface. A control coating containing uncoated nano-particle photocatalytic TiO2 dropped slightly lower to ~10 GOhm cm2. The novelty of the disclosed composite for producing self-coatings was recognized by the US Patent Office, US 9,260,630 B2.
Sullivan, James F., "Epoxy Siloxane Self-Cleaning Coating using F64PcZn/TiO2 Photocatalyst Composite" (2016). Seton Hall University Dissertations and Theses (ETDs). 2171.