Circle TiO2 Treatment
What is titanium dioxide (TiO2), and how does it work as a photocatalyst?
Titanium dioxide (TiO2) is the naturally occurring oxide of titanium. Approved by the United States Food and Drug Administration (FDA), it is considered a safe substance that is harmless to humans. It is used in paint, printing ink, plastics, paper, synthetic fibers, rubber, condensers, crayons, ceramics, electronic components, food and cosmetics, including toothpaste and teeth-whitening solutions.
Many studies have been published on the use of TiO2 as a photocatalyst for the decomposition of organic compounds. When illuminated by UV light, from the sun or internal lighting, TiO2 catalyzes the production of hydroxyl radicals, which oxidize and thereby destroy any organic compounds they contract. These include microorganisms, bacteria, viruses, fungi, mold, algae, mildew, oils, organic particulates and dirt in general.
The hydroxyl radicals are generated from ambient oxygen and water vapor, and the TiO2 is not consumed in the process (it is only a catalyst), so it continues this process indefinitely.
What are Nano TiO2 coatings?
Nano TiO2 coatings, supplied by Nano Tek-On, are specially formulated by Green Circle to create surface coatings of TiO2 that exploit its disinfectant and self-cleaning properties.
In order to work properly as a surface treatment, the TiO2 must be available in a Nano sized particles, and suspended in an inorganic solution that bonds well, and is not consumed in the catalyzed reaction. Green Circle has been able to solve all of these problems, which are detailed in the the Basic Ccience found on the Introduction page.
What factors influence the efficiency of Nano TiO2 coatings?
Light and airflow have a strong influence over the reaction of the TiO2 catalyst, as both provide elements needed for the reaction. Regular lighting is somewhat effective, especially fluorescent lights, such as those found in many kitchens and offices. However direct sunlight, UV radiation, and black lights (UVA) create the most oxidizers.
Is titanium dioxide (TiO2) safe?
FDA approved, TiO2 is harmless to humans (and pets) and is actually used widely as a food additive, as well as in paint, toothpaste and a wide variety of other day-to-day applications. The Nano TiO2 liquid coating from Green Circle is not for human consumption, but is safe to touch both before and after application / drying.
Nano TiO2 liquid should not be applied directly on pets or animals. It can and should be used however to keep pet bedding from retaining odors.
How effective is TiO2 as a disinfectant?
The hydroxyl radicals produced by the TiO2 catalyst are among the strongest of oxidizing agents, even stronger than chlorine, ozone, and peroxide. They therefore act as very powerful disinfecting agents, killing a wide variety of contaminants.
What is the history of use of TiO2 as a disinfectant?
TiO2 has wide ranging applications, and has experienced years of successful use as a disinfectant in the Japanese marketplace. The Japanese government uses TiO2 in public bathrooms to keep them smelling fresh in a low-maintenance environment. They apply TiO2 coatings to highway guard rails to keep them looking new amidst constant bombardment from hydrocarbons and particulates from vehicle exhaust. The outside of some Japanese high-rises are treated with TiO2 to make the glass and metal maintenance free.
TiO2 coatings are also widely used in the health care, food, janitorial, auto, and construction business. Many Japanese homeowners treat their mini-blinds, windows, furniture, bathrooms, showers, carpets and flooring with TiO2 solutions in order to keep them free of organic compounds, including microorganisms, bacteria, fungi, viruses, mold, algae, mildew, oils, organic particulates, and dirt in general.
Is TiO2 effective against odors?
When exposed to UV light, the Nano TiO2 coating will create oxidizers that decompose the substances which are creating the odor. The principal difference between TiO2 and other odor-absorbing substances, including activated carbons, is that TiO2 will continue this deodorizing / disinfecting function indefinitely. Other odor-adsorbing substances are consumed as they work, and so must be repeatedly replaced.
Nano TiO2 coatings will destroy odors from tobacco, formaldehyde, nitrogen dioxide, urine, fecal odor, gasoline, and many other hydrocarbon molecules in the atmosphere.
Fabrics treated with the Nano TiO2 coating will not retain odors. Car interiors treated with it, even when subjected to second-hand smoke for prolonged periods of time, will not retain tobacco odor.
Does the Nano TiO2 coating get rid of cigarette odors from tar and nicotine that have penetrated surfaces?
Yes. If a surface contaminated with second-hand smoke is treated with the Nano TiO2 coating, the odor will soon disappear. However, the discoloration caused by second-hand smoke does not disappear. It is therefore advisable to first wash smoke-contaminated surfaces that show discoloration before treatment.
How long does the Nano TiO2 coating have be exposed to UV light before it releases oxidizers into the air to get rid of indoor air pollution?
This process begins immediately, but varies with the strength of the UV light striking the TiO2. Regular lighting will activate it somewhat, especially fluorescent lights, such as those found in many kitchens and offices. However it is direct sunlight, UV radiation, and black lights (UVA) that create the most oxidizers.
How does the Nano TiO2 coating prevent and remove contamination from surfaces?
Airborne contaminants such as second-hand smoke, car exhaust, molds, viruses, bacteria, and other organic compounds cannot adhere to surfaces treated with the Nano TiO2 coating because they are oxidized by it. They are broken down and are discarded as harmless substances.
Why does the Nano TiO2 coating have a sterilizing and antimicrobial effect?
The longtime standard for killing airborne microorganisms has been strong UVC radiation. (over 20,000 μW of UVGI per second). UVC germicidal radiation kills microbes by destroying their DNA. However, some microorganisms, anthrax in particular, have very strong DNA coatings and can resist even 30,000 μW of UVGI.
The Nano TiO2 coating works in a different way, as TiO2 decomposes and destroys the cell membrane, not the DNA. Most microbes are single-celled organisms, so they die quickly when any part of them comes in contact with a treated surface. Accordingly, TiO2 even kills MRSA (Staphylococcus Aureus), a major cause of hospital infections. Japanese hospitals have demonstrated great anti-bacterial results with Nano TiO2 treatment.
The Nano TiO2 coating has been proven to kill microbes that are immune to antibiotics. Further, due to its oxidizing mechanism, it even decomposes toxins that are discharged when microbes die (Verotoxins, Enterotoxins), rendering them into harmless vapors.
What are some of the more popular applications for the Nano TiO2 coating?
Bathrooms, floor tiles, sinks, showers, car interiors (to remove and prevent tobacco odors), kitchen counters, furniture, carpets (especially with pets), curtains, mini-blinds, windows exposed to light, ceiling fans, outdoor furniture, house gutters (keeping them mold-free), concrete, brick – almost anything in a home or office environment that would benefit from having self-cleaning, deodorizing and disinfecting properties.
Can the Nano TiO2 coating be applied to carpets?
Yes, and with great results! Carpets treated with Nano TiO2 will resist not only odors and grime, but also pests such as fleas. Carpets will last much longer as a result. For this reason, carpets and fabrics in trains and public transportation are now being treated with Nano TiO2 in Japan.
Does the Nano TiO2 coating cause any fabric discoloration or any streaking effects on solid surfaces?
Nano TiO2 coatings can be applied to fabrics, curtains, carpets, woods, tiles, ceramics, glass, even metal and painted surfaces. If the surface is exposed to direct sunlight, it should not be applied to black or very dark colored surfaces, as the oxidation process can remove some pigments from the surface. Indoor light is not strong enough to cause this oxidative reaction however.
When spraying any surface with the Nano TiO2 coating, it is always advisable to spray a small test area first, and then allow it to dry, to make sure the solution does not react with the surface.
Do not apply the Nano TiO2 coating to leather, silk, or fine garments.
How is the Nano TiO2 coating applied?
Once a small area test has been performed, and there is confidence that the fabric or material can safely be treated, it can be brushed or sprayed onto surfaces.
When applied to fabrics, spray the surface until it is completely moistened, then a brush (of any sort) should be used to work the solution into the fabric.
When applied to non-fabric surfaces (plastic, metal, glass, etc.) the initial coating will leave a fine milky residue. Allow the area to completely dry, then wait several hours and wipe the area with a damp cloth.
How long does the Nano TiO2 coating take it to dry?
A film will form once the liquid has completely disappeared. The time needed for this to occur (evaporation time) will vary with temperature, wind, and film thickness. Generally speaking, it only takes 5 to 15 minutes to dry on solid surfaces and around one hour or longer to dry on fabrics. Use a blow dryer to speed up the drying process as well as aid with the bonding process.
After the Nano TiO2 coating is applied, how long does it last?
The Nano TiO2 coating forms bonds that are semi-permanent, depending on the substrate to which it is applied. Physically flexible materials, like carpets, mats and clothing, may undergo a physical peeling off as they are repeatedly reshaped over time. In this case it is recommended that the coating be reapplied every three years.
Generally speaking, the Nano TiO2 coating has a service life of five-to-ten years, or even longer on surfaces that do not experience much contact. The treatment will outlast many materials such as curtains, carpets and shingles.
Does the Nano TiO2 coating work in cold environments such as freezers?
Yes. Microbes that come in contact with a treated surface will be destroyed.
After application, does the Nano TiO2 coating produce any odor?
No, it does not have any odor.
Does the Nano TiO2 coating have a shelf life?
Basically there is no shelf life. The solution should be stored in a dark, cool environment over longer periods however.