Nano-titanium dioxide TIO2 has high photocatalytic activity and has very valuable optical properties. With stable chemical properties and abundant sources of raw materials, it is currently the most promising photocatalyst.
According to the crystal type, it can be divided into: T689 rutile nano titanium dioxide and T681 anatase nano titanium dioxide.
According to its surface characteristics, it can be divided into: hydrophilic nano titanium dioxide and lipophilic nano titanium dioxide.
Nano titanium dioxide TIO2 mainly has two crystal forms: Anatase and Rutile. Rutile titanium dioxide is more stable and dense than anatase titanium dioxide, has higher hardness, density, dielectric constant and refractive index, and its hiding power and tinting power are also higher. The anatase-type titanium dioxide has higher reflectivity in the short-wave part of visible light than the rutile-type titanium dioxide, has a bluish tint, and has lower ultraviolet absorption capacity than the rutile-type, and has a higher photocatalytic activity than the rutile-type. Under certain conditions, anatase titanium dioxide can be converted into rutile titanium dioxide.
Environmental protection applications:
Including the treatment of organic pollutants (hydrocarbons, halogenated hydrocarbons, carboxylic acids, surfactants, dyes, nitrogen-containing organics, organic phosphorus pesticides, etc.), the treatment of inorganic pollutants (photocatalysis can solve Cr6+, Hg2+, Pb2+, etc.) Pollution of heavy metal ions) and indoor environmental purification (the degradation of indoor ammonia, formaldehyde and benzene by photocatalytic green coatings).
Applications in health care:
Nano-titanium dioxide decomposes bacteria under the action of photocatalysis to achieve antibacterial effect, killing bacteria and viruses, and can be used for sterilization and disinfection of domestic water; glass, ceramics, etc. loaded with TIO2 photocatalysis are used in various sanitary facilities such as hospitals, hotels, homes, etc. Ideal material for antibacterial and deodorizing. It can also inactivate certain cancer-causing cells.
The bactericidal effect of TiO2 lies in its quantum size effect. Although titanium dioxide (ordinary TiO2) also has a photocatalytic effect, it can also generate electron and hole pairs, but its time to reach the surface of the material is above microseconds, and it is easy to recombine. It is difficult to exert the antibacterial effect, and the nano-dispersion degree of TiO2, the electrons and holes excited by light migrate from the body to the surface, and it only takes nanoseconds, picoseconds, or even femtoseconds. The recombination of photogenerated electrons and holes is In the order of nanoseconds, it can quickly migrate to the surface, attack bacterial organisms, and play a corresponding antibacterial effect.
Anatase nano titanium dioxide has high surface activity, strong antibacterial ability, and the product is easy to disperse. Tests have shown that nano-titanium dioxide has strong bactericidal ability against Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Salmonella and Aspergillus. It has been deeply approved and widely used in antibacterial products in the fields of textiles, ceramics, rubber, and medicine.
Anti-fogging and self-cleaning coating:
Under ultraviolet light irradiation, water completely infiltrates the titanium dioxide film. Therefore, coating a layer of nano-titanium dioxide on bathroom mirrors, car glass and rearview mirrors can play a role in preventing fogging. It can also realize the self-cleaning of the surface of street lamps, highway guardrails, and building exterior wall tiles.
The results of the study found that under the action of sunlight or ultraviolet rays in the light, Ti02 activates and generates free radicals with high catalytic activity, which can produce strong photooxidation and reduction capabilities, and can catalyze and photodegrade various formaldehyde attached to the surface of objects. Such as organic matter and some inorganic matter. Can play a function of purifying indoor air.
UV shielding function
Any titanium dioxide has a certain ability to absorb ultraviolet rays, especially the long-wave ultraviolet rays that are harmful to the human body, UVAUVB, have a strong absorption capacity. Excellent chemical stability, thermal stability, non-toxicity and other properties. Ultra-fine titanium dioxide has a stronger ability to absorb ultraviolet rays due to its smaller particle size (transparent) and greater activity. In addition, it has a clear color tone, low abrasion, and good easy dispersion. It is determined that titanium dioxide is the most widely used inorganic raw material in cosmetics. According to its different functions in cosmetics, different qualities of titanium dioxide can be used. The whiteness and opacity of titanium dioxide can be used to make cosmetics have a wide range of colors. When titanium dioxide is used as a white additive, T681 anatase titanium dioxide is mainly used, but when the hiding power and light resistance are considered. It is better to use T689 rutile titanium dioxide.